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Acute Trauma to the Foot

Introduction/Background Acute injuries to the foot are frequently encountered in the setting of the emergency room and in general practice. The clinical indications for imaging (known as the Ottawa rules) have been developed to minimize unnecessary radiographs, and their utility is well documented by multiple studies. The most commonly accepted form of these rules is the following: A series of foot radiographs is required only if there is pain in the midfoot and any one of the following: 1) point bone tenderness of the navicular; 2) point bone tenderness of the base of the fifth metatarsal; or 3) inability to bear weight or to walk 4 steps (immediately after the injury or at the emergency department). A meta-analysis (10 studies encompassing 3,725 patients) of the Ottawa rules for the foot showed that these rules have a sensitivity of 99% and a median specificity of 26% for combined evaluation of the ankle and midfoot [1]. The Ottawa rules for the ankle and midfoot have been shown to be effective for the pediatric population (>5 years of age) [2]. Including the added criterion of swelling yields a sensitivity and specificity for fracture of 100% and 55% for the malleolar zone and 50% and 40% for the midfoot, respectively [3,4]. Exclusionary Criteria Multiple conditions or scenarios preclude the use of the Ottawa rules for determining if imaging is necessary [5,6]. It has been reported that the Ottawa rules for the foot should not be used or should be used with great caution in the following clinical situations: penetrating trauma, pregnancy, any skin wound, transferred with radiographs already taken, >10 days after trauma, a return visit for continued traumatic foot pain, in the setting of polytrauma, altered sensorium, neurologic abnormality affecting the foot, or underlying bone disease [7].

Acute Trauma to the Foot. Introduction/Background Acute injuries to the foot are frequently encountered in the setting of the emergency room and in general practice. The clinical indications for imaging (known as the Ottawa rules) have been developed to minimize unnecessary radiographs, and their utility is well documented by multiple studies. The most commonly accepted form of these rules is the following: A series of foot radiographs is required only if there is pain in the midfoot and any one of the following: 1) point bone tenderness of the navicular; 2) point bone tenderness of the base of the fifth metatarsal; or 3) inability to bear weight or to walk 4 steps (immediately after the injury or at the emergency department). A meta-analysis (10 studies encompassing 3,725 patients) of the Ottawa rules for the foot showed that these rules have a sensitivity of 99% and a median specificity of 26% for combined evaluation of the ankle and midfoot [1]. The Ottawa rules for the ankle and midfoot have been shown to be effective for the pediatric population (>5 years of age) [2]. Including the added criterion of swelling yields a sensitivity and specificity for fracture of 100% and 55% for the malleolar zone and 50% and 40% for the midfoot, respectively [3,4]. Exclusionary Criteria Multiple conditions or scenarios preclude the use of the Ottawa rules for determining if imaging is necessary [5,6]. It has been reported that the Ottawa rules for the foot should not be used or should be used with great caution in the following clinical situations: penetrating trauma, pregnancy, any skin wound, transferred with radiographs already taken, >10 days after trauma, a return visit for continued traumatic foot pain, in the setting of polytrauma, altered sensorium, neurologic abnormality affecting the foot, or underlying bone disease [7].

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Acute Trauma to the Foot

Other clinical scenarios of foot trauma not directly addressed by the Ottawa rules include trauma to the metatarsal heads and toes and penetrating trauma with concern for a foreign body in the soft tissues. Also, there is little in the literature on medical decision making of when to order a radiographic study of the toes [8]. Discussion of Procedures by Variant Variant 1: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are negative. No suspected abnormalities in regions not evaluated by the Ottawa rules. Initial imaging. When assessing acute trauma to the foot, it is very important to determine that there are no exclusionary criteria for evaluation by Ottawa rules, in which case the rules cannot be applied; see Variant 3. In addition, there are clinical scenarios that are not specifically assessed by the Ottawa rules because the rules mainly address injuries to the midfoot. Such scenarios, for example, include injuries to the forefoot; see Variant 4. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org Acute Trauma to the Foot Radiography Foot The Ottawa rules were designed to minimize unnecessary radiographs for patients with acute ankle and foot injuries [6]. The Ottawa rules for acute trauma to the foot are fairly well established and have been validated by multiple institutional trials verifying the 99% sensitivity in determining the presence of a foot fracture [1,9,10].

Acute Trauma to the Foot. Other clinical scenarios of foot trauma not directly addressed by the Ottawa rules include trauma to the metatarsal heads and toes and penetrating trauma with concern for a foreign body in the soft tissues. Also, there is little in the literature on medical decision making of when to order a radiographic study of the toes [8]. Discussion of Procedures by Variant Variant 1: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are negative. No suspected abnormalities in regions not evaluated by the Ottawa rules. Initial imaging. When assessing acute trauma to the foot, it is very important to determine that there are no exclusionary criteria for evaluation by Ottawa rules, in which case the rules cannot be applied; see Variant 3. In addition, there are clinical scenarios that are not specifically assessed by the Ottawa rules because the rules mainly address injuries to the midfoot. Such scenarios, for example, include injuries to the forefoot; see Variant 4. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through society representation on expert panels. Participation by representatives from collaborating societies on the expert panel does not necessarily imply individual or society endorsement of the final document. Reprint requests to: publications@acr.org Acute Trauma to the Foot Radiography Foot The Ottawa rules were designed to minimize unnecessary radiographs for patients with acute ankle and foot injuries [6]. The Ottawa rules for acute trauma to the foot are fairly well established and have been validated by multiple institutional trials verifying the 99% sensitivity in determining the presence of a foot fracture [1,9,10].

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The more serious potential problems in determining the need for imaging occurs in the patient who does not meet the inclusion criteria for imaging by the Ottawa rules of the foot. These inclusionary criteria are stated in the Introduction/Background section [5,6]; added criterion of swelling increases sensitivity and specificity [3,4]. One should carefully evaluate the patient to make sure they do not meet any of the exclusionary criteria before implementing the Ottawa rules. Radiographs may be appropriate in certain clinical scenarios when Ottawa rules cannot be applied. Also, trauma to the distal forefoot (metatarsal heads and toes) is not directly addressed by the Ottawa rules. In general, if a fracture of a toe is suspected, radiographs can document or rule out a fracture [11,12]. CT Foot In this clinical scenario and in absence of exclusionary criteria for the Ottawa rules, CT is not routinely used as the first imaging study for the evaluation of acute trauma to the foot. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot. US Foot A preliminary ultrasound (US) study has had less successful results compared with radiographic evaluation, with 90.9% sensitivity and specificity for detecting fracture [13]. A recent consensus paper from the European Society of Musculoskeletal Radiology [14] assigned low grading scores for US assessment of talus and bony avulsions. Variant 2: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are positive. Initial imaging. Radiography Foot Radiographs are indicated by positive Ottawa rules with 99% sensitivity in determining the presence of a foot fracture [1,9,10]. Radiographs are the mainstay of initial imaging in the setting of acute foot trauma. Initial imaging typically consists of a 3-view study with the possibility of additional views as indicated by the clinical setting [8].

Acute Trauma to the Foot. The more serious potential problems in determining the need for imaging occurs in the patient who does not meet the inclusion criteria for imaging by the Ottawa rules of the foot. These inclusionary criteria are stated in the Introduction/Background section [5,6]; added criterion of swelling increases sensitivity and specificity [3,4]. One should carefully evaluate the patient to make sure they do not meet any of the exclusionary criteria before implementing the Ottawa rules. Radiographs may be appropriate in certain clinical scenarios when Ottawa rules cannot be applied. Also, trauma to the distal forefoot (metatarsal heads and toes) is not directly addressed by the Ottawa rules. In general, if a fracture of a toe is suspected, radiographs can document or rule out a fracture [11,12]. CT Foot In this clinical scenario and in absence of exclusionary criteria for the Ottawa rules, CT is not routinely used as the first imaging study for the evaluation of acute trauma to the foot. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot. US Foot A preliminary ultrasound (US) study has had less successful results compared with radiographic evaluation, with 90.9% sensitivity and specificity for detecting fracture [13]. A recent consensus paper from the European Society of Musculoskeletal Radiology [14] assigned low grading scores for US assessment of talus and bony avulsions. Variant 2: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are positive. Initial imaging. Radiography Foot Radiographs are indicated by positive Ottawa rules with 99% sensitivity in determining the presence of a foot fracture [1,9,10]. Radiographs are the mainstay of initial imaging in the setting of acute foot trauma. Initial imaging typically consists of a 3-view study with the possibility of additional views as indicated by the clinical setting [8].

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Additional views, such as axial calcaneal view, can be useful in patients with suspected calcaneal fracture [15] because addition of this view increases specificity in diagnosing calcaneal fractures and sensitivity in distinguishing intra-articular calcaneal fractures. Radiography Foot with Weightbearing If there are clinical signs of a Lisfranc injury, obtaining weightbearing radiographs is recommended when possible because nonweightbearing radiographs are not reliable for detection of subtle injuries. Weightbearing views have been shown to increase the abnormal alignment at the Lisfranc joint, thus making it easier to identify a Lisfranc injury [16,19]. The inclusion of both feet on AP radiographs can help in the detection of subtle malalignment when compared with the uninjured side [20]. CT Foot CT is commonly used in evaluating the true extent of osseous injury in complex fractures and at times is used as the initial imaging study in polytrauma patients and in complex regions such as the midfoot [21,22]. CT is not routinely used as the first imaging study for the evaluation of acute trauma to the foot with positive Ottawa rules when exclusionary criteria do not apply. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot with positive Ottawa rules. Acute Trauma to the Foot US Foot A preliminary US study had less successful results compared with radiographic evaluation, with 90.9% sensitivity and specificity for detecting fracture [13]. In the presence of localized tenderness, one study reported US sensitivity and specificity of 100% and 96% for fifth metatarsal fractures and 40% and 93% for navicular fractures, respectively [23]. A recent consensus paper from European Society of Musculoskeletal Radiology [14] assigned low grading scores for US assessment of talus and bony avulsions. Variant 3: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules cannot be evaluated due to exclusionary criteria.

Acute Trauma to the Foot. Additional views, such as axial calcaneal view, can be useful in patients with suspected calcaneal fracture [15] because addition of this view increases specificity in diagnosing calcaneal fractures and sensitivity in distinguishing intra-articular calcaneal fractures. Radiography Foot with Weightbearing If there are clinical signs of a Lisfranc injury, obtaining weightbearing radiographs is recommended when possible because nonweightbearing radiographs are not reliable for detection of subtle injuries. Weightbearing views have been shown to increase the abnormal alignment at the Lisfranc joint, thus making it easier to identify a Lisfranc injury [16,19]. The inclusion of both feet on AP radiographs can help in the detection of subtle malalignment when compared with the uninjured side [20]. CT Foot CT is commonly used in evaluating the true extent of osseous injury in complex fractures and at times is used as the initial imaging study in polytrauma patients and in complex regions such as the midfoot [21,22]. CT is not routinely used as the first imaging study for the evaluation of acute trauma to the foot with positive Ottawa rules when exclusionary criteria do not apply. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot with positive Ottawa rules. Acute Trauma to the Foot US Foot A preliminary US study had less successful results compared with radiographic evaluation, with 90.9% sensitivity and specificity for detecting fracture [13]. In the presence of localized tenderness, one study reported US sensitivity and specificity of 100% and 96% for fifth metatarsal fractures and 40% and 93% for navicular fractures, respectively [23]. A recent consensus paper from European Society of Musculoskeletal Radiology [14] assigned low grading scores for US assessment of talus and bony avulsions. Variant 3: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules cannot be evaluated due to exclusionary criteria.

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Acute Trauma to the Foot

Initial imaging. Multiple conditions or scenarios preclude the use of the Ottawa rules for determining if imaging is necessary [5,6]. It has been reported that the Ottawa rules for the foot should not be used or should be used with great caution in the following clinical situations: penetrating trauma, pregnancy, any skin wound, transferred with radiographs already taken, >10 days after trauma, a return visit for continued traumatic foot pain, in the setting of polytrauma, altered sensorium, neurologic abnormality affecting the foot, or underlying bone disease [7]. Radiography Foot If a foot fracture is suspected in a neurologically compromised patient, including patients with diabetic neuropathy, the foot should be radiographed. The Ottawa rules should not be applied in this clinical setting because pain perception may be diminished, no point tenderness will be elicited with palpation, and the patient may be able to ambulate even if a fracture is present [5]. Polytrauma and penetrating trauma also constitute exceptions to the implementations of the Ottawa rules. Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. The best initial imaging study for a foreign body in the foot depends on whether or not the suspected foreign body is radiopaque (eg, gravel, both leaded and nonleaded glass, or metal). Radiographic evaluation for a radiopaque foreign body has approximately 98% sensitivity [25]. If an unembedded fragment of the foreign body is available, then imaging it alongside the foot might provide more information as to the morphology and density of the foreign body. CT Foot CT is commonly used in evaluating the true extent of osseous injury in complex fractures and at times is used as the initial imaging study in polytrauma patients and in complex regions such as the midfoot [21,22]. In the polytrauma patient, approximately 25% of midfoot fractures identified on CT are overlooked on radiographs [21].

Acute Trauma to the Foot. Initial imaging. Multiple conditions or scenarios preclude the use of the Ottawa rules for determining if imaging is necessary [5,6]. It has been reported that the Ottawa rules for the foot should not be used or should be used with great caution in the following clinical situations: penetrating trauma, pregnancy, any skin wound, transferred with radiographs already taken, >10 days after trauma, a return visit for continued traumatic foot pain, in the setting of polytrauma, altered sensorium, neurologic abnormality affecting the foot, or underlying bone disease [7]. Radiography Foot If a foot fracture is suspected in a neurologically compromised patient, including patients with diabetic neuropathy, the foot should be radiographed. The Ottawa rules should not be applied in this clinical setting because pain perception may be diminished, no point tenderness will be elicited with palpation, and the patient may be able to ambulate even if a fracture is present [5]. Polytrauma and penetrating trauma also constitute exceptions to the implementations of the Ottawa rules. Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. The best initial imaging study for a foreign body in the foot depends on whether or not the suspected foreign body is radiopaque (eg, gravel, both leaded and nonleaded glass, or metal). Radiographic evaluation for a radiopaque foreign body has approximately 98% sensitivity [25]. If an unembedded fragment of the foreign body is available, then imaging it alongside the foot might provide more information as to the morphology and density of the foreign body. CT Foot CT is commonly used in evaluating the true extent of osseous injury in complex fractures and at times is used as the initial imaging study in polytrauma patients and in complex regions such as the midfoot [21,22]. In the polytrauma patient, approximately 25% of midfoot fractures identified on CT are overlooked on radiographs [21].

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Acute Trauma to the Foot

Therefore, CT is essential for appropriate treatment planning and determining the true extent of osseous injuries in the polytrauma patient and can be used as primary imaging technique in high-energy polytrauma patients. Initial clinical experience suggests that cone-beam CT of the foot or ankle of pediatric patients is a viable lower- dose alternative to multidetector CT [26]. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of peripheral neuropathy, penetrating trauma, or polytrauma. US Foot US is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of peripheral neuropathy or polytrauma. Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. US is the imaging modality of choice if the foreign body is not radiopaque (eg, wood or plastic), with a reported 90% sensitivity for visualizing wooden foreign bodies in some clinical and experimental studies [27,28]. US can identify a foreign body and also help localize it and determine if it involves a tendon or a muscle and to evaluate for an abscess. Variant 4: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are negative. Suspected pathology in an anatomic area not addressed by Ottawa rules (not involving the midfoot; eg, metatarsal-phalangeal joint, metatarsal, toe, tendon, etc). Initial imaging. In clinical situations when Ottawa rules are applicable and negative, imaging may still be desired to evaluate for injuries not assessed by the Ottawa rules. For example, clinical scenarios of acute foot trauma not directly addressed by the Ottawa rules include trauma to the metatarsal heads and toes and acute tendon injury.

Acute Trauma to the Foot. Therefore, CT is essential for appropriate treatment planning and determining the true extent of osseous injuries in the polytrauma patient and can be used as primary imaging technique in high-energy polytrauma patients. Initial clinical experience suggests that cone-beam CT of the foot or ankle of pediatric patients is a viable lower- dose alternative to multidetector CT [26]. MRI Foot MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of peripheral neuropathy, penetrating trauma, or polytrauma. US Foot US is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of peripheral neuropathy or polytrauma. Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. US is the imaging modality of choice if the foreign body is not radiopaque (eg, wood or plastic), with a reported 90% sensitivity for visualizing wooden foreign bodies in some clinical and experimental studies [27,28]. US can identify a foreign body and also help localize it and determine if it involves a tendon or a muscle and to evaluate for an abscess. Variant 4: Adult or child older than 5 years of age. Acute trauma to the foot. Ottawa rules can be evaluated without exclusionary criteria. Ottawa rules are negative. Suspected pathology in an anatomic area not addressed by Ottawa rules (not involving the midfoot; eg, metatarsal-phalangeal joint, metatarsal, toe, tendon, etc). Initial imaging. In clinical situations when Ottawa rules are applicable and negative, imaging may still be desired to evaluate for injuries not assessed by the Ottawa rules. For example, clinical scenarios of acute foot trauma not directly addressed by the Ottawa rules include trauma to the metatarsal heads and toes and acute tendon injury.

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Acute Trauma to the Foot Radiography Foot Metatarsal-Phalangeal Joint Injury The best initial imaging study for evaluating hallux plantar plate disruption after metatarsal-phalangeal (MTP) joint injury is weightbearing AP, lateral, and sesamoid axial views, with addition of comparison radiographs of the contralateral foot [29]. Radiographs may also indirectly evaluate lesser metatarsophalangeal plantar plate injury [30]. The combination of a positive drawer test coupled with transverse deviation of the third MTP joint on radiographs can be used to diagnose high-grade plantar plate tear of the second MTP joint [31]. A forced dorsiflexion lateral view of the hallux MTP joint is recommended if there is clinical suspicion of plantar plate injury of the first MTP joint [29]. Radiography Foot with Weightbearing The best initial imaging study for evaluating hallux plantar plate disruption after MTP joint injury is weightbearing AP, lateral, and sesamoid axial views with addition of comparison radiographs of the contralateral foot [29,32]. MRI Foot MRI is the most sensitive modality for the detection of occult fracture and acute bone stress changes [34,35]. MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in setting of suspected MTP joint injury or occult fracture. Both MRI and US are used in evaluating soft-tissue injuries of the foot in the setting of acute trauma, especially when radiographs are noncontributory. Both modalities have a similar sensitivity for acute soft-tissue trauma about the ankle and foot such as ligamentous and tendinous disruption [36- 38]. US Foot US is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of suspected MTP joint injury or occult fracture. US has been shown to be sensitive for the diagnosis of acute tendon rupture or tendon dislocation in the foot [36,39,40].

Acute Trauma to the Foot. Acute Trauma to the Foot Radiography Foot Metatarsal-Phalangeal Joint Injury The best initial imaging study for evaluating hallux plantar plate disruption after metatarsal-phalangeal (MTP) joint injury is weightbearing AP, lateral, and sesamoid axial views, with addition of comparison radiographs of the contralateral foot [29]. Radiographs may also indirectly evaluate lesser metatarsophalangeal plantar plate injury [30]. The combination of a positive drawer test coupled with transverse deviation of the third MTP joint on radiographs can be used to diagnose high-grade plantar plate tear of the second MTP joint [31]. A forced dorsiflexion lateral view of the hallux MTP joint is recommended if there is clinical suspicion of plantar plate injury of the first MTP joint [29]. Radiography Foot with Weightbearing The best initial imaging study for evaluating hallux plantar plate disruption after MTP joint injury is weightbearing AP, lateral, and sesamoid axial views with addition of comparison radiographs of the contralateral foot [29,32]. MRI Foot MRI is the most sensitive modality for the detection of occult fracture and acute bone stress changes [34,35]. MRI is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in setting of suspected MTP joint injury or occult fracture. Both MRI and US are used in evaluating soft-tissue injuries of the foot in the setting of acute trauma, especially when radiographs are noncontributory. Both modalities have a similar sensitivity for acute soft-tissue trauma about the ankle and foot such as ligamentous and tendinous disruption [36- 38]. US Foot US is not routinely used as the first imaging study for the evaluation of acute trauma to the foot in the setting of suspected MTP joint injury or occult fracture. US has been shown to be sensitive for the diagnosis of acute tendon rupture or tendon dislocation in the foot [36,39,40].

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Acute Trauma to the Foot

Fluoroscopy Foot In addition to routine radiographs, fluoroscopy has been suggested in assessment of a hallux MTP joint injury with direct fluoroscopic evaluation of sesamoid tracking distally with great toe extension at the MTP joint on forced dorsiflexion lateral view or fluoroscopy [29]. Variant 5: Adult or child older than 5 years of age. Acute trauma to the foot. Suspect Lisfranc injury, tendon injury, or occult fracture or dislocation. Radiographs are normal or equivocal. Next imaging study. CT Foot Lisfranc Injury CT has been advocated as the primary imaging technique in acute hyperflexion injury and high-energy polytrauma (especially if the patient is not able to bear weight) [33,38,41-45]. CT is useful in demonstrating the multiple metatarsal and cuneiform fractures that can be associated with a ligamentous Lisfranc injury [21,22,33]. CT is typically used for preoperative planning for fracture treatment and evaluation. In the patient with a suspected Lisfranc injury and normal radiographs, the literature supports further advanced imaging by MRI and CT [21,33,43,46]. Acute Tendinous Injury CT imaging has been shown to be an effective way of documenting various tendon entrapment and dislocations, in particularly peroneal dislocations and peroneal retinacular injuries, which are associated with comminuted calcaneal fractures [47-50]. MRI Foot MRI can show osseous injuries that are not visible radiographically including fractures and high-grade contusions associated with prolonged recovery times in elite athletes [51]. MRI can demonstrate ligamentous and osseous Acute Trauma to the Foot injuries in midtarsal (Chopart) sprains, which frequently accompany acute ankle injuries [52,53]. If radiographs are negative, MRI can be obtained in select patients with forefoot pain because of its increased sensitivity for the early detection of metatarsal head subchondral fracture [54].

Acute Trauma to the Foot. Fluoroscopy Foot In addition to routine radiographs, fluoroscopy has been suggested in assessment of a hallux MTP joint injury with direct fluoroscopic evaluation of sesamoid tracking distally with great toe extension at the MTP joint on forced dorsiflexion lateral view or fluoroscopy [29]. Variant 5: Adult or child older than 5 years of age. Acute trauma to the foot. Suspect Lisfranc injury, tendon injury, or occult fracture or dislocation. Radiographs are normal or equivocal. Next imaging study. CT Foot Lisfranc Injury CT has been advocated as the primary imaging technique in acute hyperflexion injury and high-energy polytrauma (especially if the patient is not able to bear weight) [33,38,41-45]. CT is useful in demonstrating the multiple metatarsal and cuneiform fractures that can be associated with a ligamentous Lisfranc injury [21,22,33]. CT is typically used for preoperative planning for fracture treatment and evaluation. In the patient with a suspected Lisfranc injury and normal radiographs, the literature supports further advanced imaging by MRI and CT [21,33,43,46]. Acute Tendinous Injury CT imaging has been shown to be an effective way of documenting various tendon entrapment and dislocations, in particularly peroneal dislocations and peroneal retinacular injuries, which are associated with comminuted calcaneal fractures [47-50]. MRI Foot MRI can show osseous injuries that are not visible radiographically including fractures and high-grade contusions associated with prolonged recovery times in elite athletes [51]. MRI can demonstrate ligamentous and osseous Acute Trauma to the Foot injuries in midtarsal (Chopart) sprains, which frequently accompany acute ankle injuries [52,53]. If radiographs are negative, MRI can be obtained in select patients with forefoot pain because of its increased sensitivity for the early detection of metatarsal head subchondral fracture [54].

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Lisfranc Injury MRI has been advocated as a sensitive diagnostic test in evaluation of Lisfranc ligamentous complex (especially if the patient is not able to bear weight), and 3-D volumetric acquisitions have proven superiority over orthogonal proton density fat-suppressed imaging [33,38,41-45]. There is a high correlation between MRI and intraoperative findings for an unstable Lisfranc injury [44]. In the patient with a suspected Lisfranc injury and normal radiographs, the literature supports further advanced imaging by MRI and CT [21,33,43,46]. Acute Tendinous Rupture MRI tends to be used as a screening tool when one is not certain of the specific tendon injury or if concomitant osseous injury is suspected. Both MRI and US have been shown to be sensitive for the diagnosis of acute tendon rupture or dislocation in the foot [39]. In a surgically confirmed study, MRI was shown to have 83% sensitivity for diagnosing tendon and ligament traumatic injuries about the foot and ankle [37]. US Foot The importance of focused US examinations is emphasized in the literature [57,58]. Protocol-based US evaluation identified 97.4% of symptomatic abnormalities in the distal extremities (including the foot), with additional accuracy obtained with focused examination [57]. Lisfranc Injury Although the literature evidence is limited, US may hold promise as an alternative method to accurately evaluate for a significant Lisfranc injury providing direct and indirect assessment of the Lisfranc ligamentous complex as well as dynamic evaluation with weightbearing as demonstrated in a series of 10 patients [59]. Dorsal component of Lisfranc ligament is amenable to direct US evaluation [59,60], although this structure may not be critical for stability for the Lisfranc joint [20,32]. The physiologic deformation of the dorsal Lisfranc ligament resulting from functional loading emphasized the need for normative US data as well as proper positioning when bilateral evaluation is performed [61,62].

Acute Trauma to the Foot. Lisfranc Injury MRI has been advocated as a sensitive diagnostic test in evaluation of Lisfranc ligamentous complex (especially if the patient is not able to bear weight), and 3-D volumetric acquisitions have proven superiority over orthogonal proton density fat-suppressed imaging [33,38,41-45]. There is a high correlation between MRI and intraoperative findings for an unstable Lisfranc injury [44]. In the patient with a suspected Lisfranc injury and normal radiographs, the literature supports further advanced imaging by MRI and CT [21,33,43,46]. Acute Tendinous Rupture MRI tends to be used as a screening tool when one is not certain of the specific tendon injury or if concomitant osseous injury is suspected. Both MRI and US have been shown to be sensitive for the diagnosis of acute tendon rupture or dislocation in the foot [39]. In a surgically confirmed study, MRI was shown to have 83% sensitivity for diagnosing tendon and ligament traumatic injuries about the foot and ankle [37]. US Foot The importance of focused US examinations is emphasized in the literature [57,58]. Protocol-based US evaluation identified 97.4% of symptomatic abnormalities in the distal extremities (including the foot), with additional accuracy obtained with focused examination [57]. Lisfranc Injury Although the literature evidence is limited, US may hold promise as an alternative method to accurately evaluate for a significant Lisfranc injury providing direct and indirect assessment of the Lisfranc ligamentous complex as well as dynamic evaluation with weightbearing as demonstrated in a series of 10 patients [59]. Dorsal component of Lisfranc ligament is amenable to direct US evaluation [59,60], although this structure may not be critical for stability for the Lisfranc joint [20,32]. The physiologic deformation of the dorsal Lisfranc ligament resulting from functional loading emphasized the need for normative US data as well as proper positioning when bilateral evaluation is performed [61,62].

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Acute Trauma to the Foot

Turf Toe and Plantar Plate Injuries US in the sagittal plane best visualizes the plantar plate between the flexor tendon and hyaline cartilage of the metatarsal head [63]. US has shown a 96% sensitivity compared with 87% sensitivity for MRI for the detection of lesser toe plantar plate tears; however, both modalities have poor specificity [64]. Acute Tendinous Rupture Both MRI and US have been shown to be sensitive for the diagnosis of acute tendon rupture or dislocation in the foot [39]. US has also been reported to have a high sensitivity for peroneal tendon tears [65]. Variant 6: Adult or child older than 5 years of age. Acute trauma to the foot. Suspect penetrating trauma with a foreign body. Radiographs of the foot are negative. Next imaging study. CT Foot An experimental study for detection of a variety of foreign bodies (eg, fresh wood, dry wood, glass, porcelain, and plastic fragments) reported 63% sensitivity and 98% specificity for CT for detecting a foreign body [66]. CT was superior to MRI in identifying water-rich fresh wood. MRI Foot An experimental study reported 58% sensitivity and 100% specificity for MRI for detecting a foreign body [66]. In a clinical study including 8 patients with wooden foreign bodies, MRI showed the surrounding inflammatory response in all patients [28]. US Foot Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. US is the imaging modality of choice if the foreign body is not radiopaque (eg, wood or plastic), Acute Trauma to the Foot with a reported 90% sensitivity for visualizing wooden foreign bodies in some clinical and experimental studies [27,28]. US can be used effectively to locate wooden foreign bodies as small as 2.5 mm in length [27]. However, some experimental studies utilizing soft-tissue phantom models report lower overall sensitivity (<50%) for US for detection of foreign bodies [25].

Acute Trauma to the Foot. Turf Toe and Plantar Plate Injuries US in the sagittal plane best visualizes the plantar plate between the flexor tendon and hyaline cartilage of the metatarsal head [63]. US has shown a 96% sensitivity compared with 87% sensitivity for MRI for the detection of lesser toe plantar plate tears; however, both modalities have poor specificity [64]. Acute Tendinous Rupture Both MRI and US have been shown to be sensitive for the diagnosis of acute tendon rupture or dislocation in the foot [39]. US has also been reported to have a high sensitivity for peroneal tendon tears [65]. Variant 6: Adult or child older than 5 years of age. Acute trauma to the foot. Suspect penetrating trauma with a foreign body. Radiographs of the foot are negative. Next imaging study. CT Foot An experimental study for detection of a variety of foreign bodies (eg, fresh wood, dry wood, glass, porcelain, and plastic fragments) reported 63% sensitivity and 98% specificity for CT for detecting a foreign body [66]. CT was superior to MRI in identifying water-rich fresh wood. MRI Foot An experimental study reported 58% sensitivity and 100% specificity for MRI for detecting a foreign body [66]. In a clinical study including 8 patients with wooden foreign bodies, MRI showed the surrounding inflammatory response in all patients [28]. US Foot Both radiographs and US are useful imaging tools to exclude a foreign body in the setting of penetrating trauma to the foot [24]. US is the imaging modality of choice if the foreign body is not radiopaque (eg, wood or plastic), Acute Trauma to the Foot with a reported 90% sensitivity for visualizing wooden foreign bodies in some clinical and experimental studies [27,28]. US can be used effectively to locate wooden foreign bodies as small as 2.5 mm in length [27]. However, some experimental studies utilizing soft-tissue phantom models report lower overall sensitivity (<50%) for US for detection of foreign bodies [25].

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Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

Introduction/Background Pediatric musculoskeletal infections can result in significant morbidity, particularly given ongoing skeletal maturation, and delayed diagnosis may result in premature physeal arrest or joint damage. Among osteoarticular infections, osteomyelitis occurs twice as frequently as septic arthritis [1]. Estimates of the incidence of pediatric osteomyelitis vary widely but have been cited between 2 to 20 per 100,000 [1-4]. Concomitant joint and bone or other extra-articular infections are common in children and may occur in >50% of cases [5-7]. Septic arthritis, which most commonly occurs in the knee and hip joints, is considered an orthopedic emergency because bacterial proliferation and metabolites can rapidly result in cartilage damage [11]. The Kocher criteria, first described in 1999, are widely applied in evaluation of the hip joint as a means to distinguish septic arthritis (surgical emergency) from transient synovitis (expectant management) [14]. The criteria include fever >101.3oF, erythrocyte sedimentation rate of at least 40 mm/hour, white blood cell (WBC) count of at least 12,000 cells/mm3, and an inability to bear weight on the affected side. Satisfying more of these criteria results in higher likelihood of septic arthritis, with near 100% likelihood in patients who meet all four criteria. More recently, elevated C-reactive protein >2.0 mg/dL has been described as an accurate predictor of septic arthritis [15]. Clinical suspicion of septic arthritis is of paramount importance in management because diagnosis is made by arthrocentesis. The distribution of septic arthritis and osteomyelitis varies by age. Children <2 years of age have been reported to be more likely to have septic arthritis than osteomyelitis (P = . 0003). In children between 2 and 10 years old, osteomyelitis is slightly more common than septic arthritis, and in children from 10 to 18 years old, septic arthritis is slightly more common [6].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Introduction/Background Pediatric musculoskeletal infections can result in significant morbidity, particularly given ongoing skeletal maturation, and delayed diagnosis may result in premature physeal arrest or joint damage. Among osteoarticular infections, osteomyelitis occurs twice as frequently as septic arthritis [1]. Estimates of the incidence of pediatric osteomyelitis vary widely but have been cited between 2 to 20 per 100,000 [1-4]. Concomitant joint and bone or other extra-articular infections are common in children and may occur in >50% of cases [5-7]. Septic arthritis, which most commonly occurs in the knee and hip joints, is considered an orthopedic emergency because bacterial proliferation and metabolites can rapidly result in cartilage damage [11]. The Kocher criteria, first described in 1999, are widely applied in evaluation of the hip joint as a means to distinguish septic arthritis (surgical emergency) from transient synovitis (expectant management) [14]. The criteria include fever >101.3oF, erythrocyte sedimentation rate of at least 40 mm/hour, white blood cell (WBC) count of at least 12,000 cells/mm3, and an inability to bear weight on the affected side. Satisfying more of these criteria results in higher likelihood of septic arthritis, with near 100% likelihood in patients who meet all four criteria. More recently, elevated C-reactive protein >2.0 mg/dL has been described as an accurate predictor of septic arthritis [15]. Clinical suspicion of septic arthritis is of paramount importance in management because diagnosis is made by arthrocentesis. The distribution of septic arthritis and osteomyelitis varies by age. Children <2 years of age have been reported to be more likely to have septic arthritis than osteomyelitis (P = . 0003). In children between 2 and 10 years old, osteomyelitis is slightly more common than septic arthritis, and in children from 10 to 18 years old, septic arthritis is slightly more common [6].

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Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Osteomyelitis or Septic Arthritis-Child Typical management of uncomplicated osteomyelitis in the pediatric population consists initially of intravenous (IV) antibiotic therapy followed by a prolonged course of outpatient antibiotics, either oral or IV. However, surgical debridement may be indicated in certain scenarios, such as in the setting of subperiosteal collections, necrosis, or failure to respond to initial management. Typical management of septic arthritis consists of antibiotics, arthrotomy, irrigation, and debridement [16]. Imaging plays a critical role in characterizing and differentiating septic arthritis from osteomyelitis. Please note that chronic recurrent multifocal osteomyelitis, which affects the pediatric population and typically manifests with multiple sites of involvement, is a nonbacterial autoinflammatory disorder and as such will not be discussed in this document, which will focus on acute musculoskeletal infection. Special Imaging Considerations Evaluation for pediatric musculoskeletal infection in the setting of existing orthopedic hardware can be impacted by artifact. On CT, beam hardening artifact occurs, which can be reduced on conventional CT by corrective software, as well as filtration and calibration connection [18,19]. With the advent of dual-energy CT, metal artifact reduction can be performed to reduce beam hardening by acquisition of data at two distinct energy spectra in order to create a virtual monochromatic image to optimize visualization of bone or soft tissue [19].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Osteomyelitis or Septic Arthritis-Child Typical management of uncomplicated osteomyelitis in the pediatric population consists initially of intravenous (IV) antibiotic therapy followed by a prolonged course of outpatient antibiotics, either oral or IV. However, surgical debridement may be indicated in certain scenarios, such as in the setting of subperiosteal collections, necrosis, or failure to respond to initial management. Typical management of septic arthritis consists of antibiotics, arthrotomy, irrigation, and debridement [16]. Imaging plays a critical role in characterizing and differentiating septic arthritis from osteomyelitis. Please note that chronic recurrent multifocal osteomyelitis, which affects the pediatric population and typically manifests with multiple sites of involvement, is a nonbacterial autoinflammatory disorder and as such will not be discussed in this document, which will focus on acute musculoskeletal infection. Special Imaging Considerations Evaluation for pediatric musculoskeletal infection in the setting of existing orthopedic hardware can be impacted by artifact. On CT, beam hardening artifact occurs, which can be reduced on conventional CT by corrective software, as well as filtration and calibration connection [18,19]. With the advent of dual-energy CT, metal artifact reduction can be performed to reduce beam hardening by acquisition of data at two distinct energy spectra in order to create a virtual monochromatic image to optimize visualization of bone or soft tissue [19].

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On MRI, susceptibility artifact limits regional visualization and directly correlates with magnetic field strength. Basic metal artifact reduction can be performed by increasing bandwidth, decreasing slice thickness, increasing echo train length, and increasing matrix size [20]. Advanced MR software packages and sequences have been developed for more robust through-section and in-plane artifact reduction. Osteomyelitis commonly occurs in young children, with half of cases reportedly in children <5 years of age [13,21]. Although hematogenous bacterial seeding is the most common underlying cause for osteomyelitis, a history of trauma, often minor, is frequently elicited [11,13]. Infants and toddlers with septic arthritis or osteomyelitis often present with a limp, though it is often difficult in this population to localize a site of involvement on physical examination. In these cases, imaging is often utilized to help identify the affected site [22]. Concurrent osteomyelitis and septic arthritis are common. 3-Phase Bone Scan Area of Interest There is no relevant literature regarding the use of 3-phase bone scan of the area of interest in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. Osteomyelitis or Septic Arthritis-Child Bone Scan Whole Body There is no relevant literature regarding the use of whole-body bone scan in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest There is no relevant literature regarding the use of whole-body bone scan with 3-phase bone scan of the area of interest in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. CT Area of Interest There is no relevant literature regarding the use of CT in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age.

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. On MRI, susceptibility artifact limits regional visualization and directly correlates with magnetic field strength. Basic metal artifact reduction can be performed by increasing bandwidth, decreasing slice thickness, increasing echo train length, and increasing matrix size [20]. Advanced MR software packages and sequences have been developed for more robust through-section and in-plane artifact reduction. Osteomyelitis commonly occurs in young children, with half of cases reportedly in children <5 years of age [13,21]. Although hematogenous bacterial seeding is the most common underlying cause for osteomyelitis, a history of trauma, often minor, is frequently elicited [11,13]. Infants and toddlers with septic arthritis or osteomyelitis often present with a limp, though it is often difficult in this population to localize a site of involvement on physical examination. In these cases, imaging is often utilized to help identify the affected site [22]. Concurrent osteomyelitis and septic arthritis are common. 3-Phase Bone Scan Area of Interest There is no relevant literature regarding the use of 3-phase bone scan of the area of interest in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. Osteomyelitis or Septic Arthritis-Child Bone Scan Whole Body There is no relevant literature regarding the use of whole-body bone scan in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest There is no relevant literature regarding the use of whole-body bone scan with 3-phase bone scan of the area of interest in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age. CT Area of Interest There is no relevant literature regarding the use of CT in the initial evaluation of osteomyelitis or septic arthritis in children <5 years of age.

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Although some studies have shown no significant difference in sensitivity and specificity in diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, IV contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis, and diminished femoral head enhancement on MRI in the setting of septic arthritis in children <12 months of age correlated with development of secondary osteomyelitis [34,35]. Contrast has been shown to markedly improve detection of infection of unossified growth cartilage (chondritis) in children <6 years of age, in which the cartilage most commonly appeared normal on unenhanced sequences; hypoenhancement was more commonly noted with infection [36,37]. In one study of children <18 months of age with community acquired S aureus infection of the unossified epiphyseal cartilage, 7 of 9 cases demonstrated normal cartilage signal on noncontrast sequences; hypoenhancement or nonenhancement of involved foci was used for diagnosis [36]. In another study of children <6 years of age, focal or global cartilage nonenhancement was demonstrated in 71% of 14 patients with surgically confirmed epiphyseal osteomyelitis, compared with 21% of controls [37]. Global enhancement defects were more sensitive, noted in 43% of cases but not seen in any control cases. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis.

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Although some studies have shown no significant difference in sensitivity and specificity in diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, IV contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis, and diminished femoral head enhancement on MRI in the setting of septic arthritis in children <12 months of age correlated with development of secondary osteomyelitis [34,35]. Contrast has been shown to markedly improve detection of infection of unossified growth cartilage (chondritis) in children <6 years of age, in which the cartilage most commonly appeared normal on unenhanced sequences; hypoenhancement was more commonly noted with infection [36,37]. In one study of children <18 months of age with community acquired S aureus infection of the unossified epiphyseal cartilage, 7 of 9 cases demonstrated normal cartilage signal on noncontrast sequences; hypoenhancement or nonenhancement of involved foci was used for diagnosis [36]. In another study of children <6 years of age, focal or global cartilage nonenhancement was demonstrated in 71% of 14 patients with surgically confirmed epiphyseal osteomyelitis, compared with 21% of controls [37]. Global enhancement defects were more sensitive, noted in 43% of cases but not seen in any control cases. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis.

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Among patients who did not have osteomyelitis, 20% had contralateral abnormalities; most common diagnoses included stress reaction, soft-tissue edema, myositis, sterile joint effusion, and leukemia. Radiography Area of Interest Features of acute osteomyelitis on radiographs include periosteal reaction, a well-circumscribed focal bone lucency, and frank bone destruction. Radiographs are not sensitive in assessment of early osteomyelitis because bone destruction does not typically occur until 7 to 10 days into the disease course, and radiographs are normal until >30% osseous matrix destruction has occurred [24,40]. Radiographs, however, do have initial utility in all populations in excluding other entities that may mimic acute osteomyelitis, such as fracture or neoplasm and can be used to direct subsequent imaging evaluation [3,25,31,40]. A particularly challenging subset of patients to Osteomyelitis or Septic Arthritis-Child evaluate is those with sickle cell disease. One study found that 63% of patients with known hand or wrist osteomyelitis and underlying sickle cell disease had lytic radiographic changes or periosteal reaction, compared with 23% of patients without sickle cell disease, with the greater frequency in the sickle cell population attributed to either marrow infarction or osteomyelitis as the underlying cause for radiographic changes [41]. Radiographs are highly variable in identifying hip joint effusions, with sensitivity ranging from 20% to 73% [40,42,43]. Radiographs are also variable for identifying fluid in joints other than the hip. US Area of Interest Ultrasonography (US) is a highly sensitive method of diagnosing joint effusions, with the bulk of literature addressing the hip joint. US can reportedly detect hip effusions as small as 1 mL [44].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities; most common diagnoses included stress reaction, soft-tissue edema, myositis, sterile joint effusion, and leukemia. Radiography Area of Interest Features of acute osteomyelitis on radiographs include periosteal reaction, a well-circumscribed focal bone lucency, and frank bone destruction. Radiographs are not sensitive in assessment of early osteomyelitis because bone destruction does not typically occur until 7 to 10 days into the disease course, and radiographs are normal until >30% osseous matrix destruction has occurred [24,40]. Radiographs, however, do have initial utility in all populations in excluding other entities that may mimic acute osteomyelitis, such as fracture or neoplasm and can be used to direct subsequent imaging evaluation [3,25,31,40]. A particularly challenging subset of patients to Osteomyelitis or Septic Arthritis-Child evaluate is those with sickle cell disease. One study found that 63% of patients with known hand or wrist osteomyelitis and underlying sickle cell disease had lytic radiographic changes or periosteal reaction, compared with 23% of patients without sickle cell disease, with the greater frequency in the sickle cell population attributed to either marrow infarction or osteomyelitis as the underlying cause for radiographic changes [41]. Radiographs are highly variable in identifying hip joint effusions, with sensitivity ranging from 20% to 73% [40,42,43]. Radiographs are also variable for identifying fluid in joints other than the hip. US Area of Interest Ultrasonography (US) is a highly sensitive method of diagnosing joint effusions, with the bulk of literature addressing the hip joint. US can reportedly detect hip effusions as small as 1 mL [44].

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The absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with septic arthritis of the hip required US imaging alone to guide their management [45]. US can also be used to identify joint fluid in extremity joints other than the hip. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes such as periosteal elevation, subperiosteal collections, and soft-tissue edema [40,49,50]. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest Skeletal scintigraphy has been traditionally used to accurately detect disease in cases of suspected acute osteomyelitis with normal radiographs because scintigraphic changes are present within the first 1 to 2 days of symptoms [8]. Although multiple studies have documented the success of scintigraphy in identifying acute osteomyelitis in children, there is limited data with studies in which only the area of interest was imaged. In one study in which blood pool and delayed imaging of only the area of interest were performed, 70 of 71 cases of osteomyelitis were identified [51]. However, multifocal osteomyelitis is common in the pediatric population, particularly among young children, and as a result, whole-body bone scan is typically advocated [52]. One study, in which a 3-phase bone scan was performed followed by a whole-body scan, delayed imaging noted 19% of cases of acute osteomyelitis were noted to be multifocal osteomyelitis, with over half of those cases noted in patients <6 years of age, the majority of which were neonates [52].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. The absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with septic arthritis of the hip required US imaging alone to guide their management [45]. US can also be used to identify joint fluid in extremity joints other than the hip. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes such as periosteal elevation, subperiosteal collections, and soft-tissue edema [40,49,50]. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest Skeletal scintigraphy has been traditionally used to accurately detect disease in cases of suspected acute osteomyelitis with normal radiographs because scintigraphic changes are present within the first 1 to 2 days of symptoms [8]. Although multiple studies have documented the success of scintigraphy in identifying acute osteomyelitis in children, there is limited data with studies in which only the area of interest was imaged. In one study in which blood pool and delayed imaging of only the area of interest were performed, 70 of 71 cases of osteomyelitis were identified [51]. However, multifocal osteomyelitis is common in the pediatric population, particularly among young children, and as a result, whole-body bone scan is typically advocated [52]. One study, in which a 3-phase bone scan was performed followed by a whole-body scan, delayed imaging noted 19% of cases of acute osteomyelitis were noted to be multifocal osteomyelitis, with over half of those cases noted in patients <6 years of age, the majority of which were neonates [52].

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Single-photon emission computed tomography (SPECT)/CT offers improved characterization of osseous pathology compared to planar imaging [53]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of disease [53]. Whole-body bone scan is typically helpful when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54]. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55]. Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. In another smaller study, 9 patients who underwent whole-body scan, 100% (7 of 7) patients with osteomyelitis had increased uptake corresponding to the site of involvement [56]. In one study of 213 children referred for skeletal scintigraphy because of suspicion for acute hematogenous osteomyelitis who underwent a 3-phase bone scan of the area of interest along with whole-body delayed images, accurate diagnosis was made in 84% of cases without the need for MRI, including 92% of those diagnosed with osteomyelitis, although it should be noted that bone scan was limited regarding soft- tissue and articular pathology [57]. In another study of 65 children who underwent whole-body scan with focused evaluations of the area of interest and the contralateral side, 23 patients who were classified as having osteomyelitis all had abnormal bone scans [58].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Single-photon emission computed tomography (SPECT)/CT offers improved characterization of osseous pathology compared to planar imaging [53]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of disease [53]. Whole-body bone scan is typically helpful when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54]. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55]. Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. In another smaller study, 9 patients who underwent whole-body scan, 100% (7 of 7) patients with osteomyelitis had increased uptake corresponding to the site of involvement [56]. In one study of 213 children referred for skeletal scintigraphy because of suspicion for acute hematogenous osteomyelitis who underwent a 3-phase bone scan of the area of interest along with whole-body delayed images, accurate diagnosis was made in 84% of cases without the need for MRI, including 92% of those diagnosed with osteomyelitis, although it should be noted that bone scan was limited regarding soft- tissue and articular pathology [57]. In another study of 65 children who underwent whole-body scan with focused evaluations of the area of interest and the contralateral side, 23 patients who were classified as having osteomyelitis all had abnormal bone scans [58].

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SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease [53]. Osteomyelitis or Septic Arthritis-Child CT Area of Interest There is no relevant literature regarding the use of CT as the next imaging study in evaluation of osteomyelitis or septic arthritis in children under 5 years of age. Image-Guided Aspiration Area of Interest Primary differential considerations when a joint effusion is present in the absence of trauma are transient synovitis and septic arthritis. Although the most common locations of septic arthritis are the knee and hip joints, this can affect any joint [60]. Although most nontraumatic hip joint effusions are secondary to transient synovitis, early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate for diagnosis [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted than US guidance for aspiration was only provided in one case, and the remainder were performed using anatomic landmarks without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US-guided joint aspiration experienced shorter duration of stay and shorter duration of a limp compared with those who did not undergo joint aspiration [61]. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease [53]. Osteomyelitis or Septic Arthritis-Child CT Area of Interest There is no relevant literature regarding the use of CT as the next imaging study in evaluation of osteomyelitis or septic arthritis in children under 5 years of age. Image-Guided Aspiration Area of Interest Primary differential considerations when a joint effusion is present in the absence of trauma are transient synovitis and septic arthritis. Although the most common locations of septic arthritis are the knee and hip joints, this can affect any joint [60]. Although most nontraumatic hip joint effusions are secondary to transient synovitis, early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate for diagnosis [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted than US guidance for aspiration was only provided in one case, and the remainder were performed using anatomic landmarks without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US-guided joint aspiration experienced shorter duration of stay and shorter duration of a limp compared with those who did not undergo joint aspiration [61]. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63].

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Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, IV contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis, and diminished femoral head enhancement on MRI has been noted in the setting of septic arthritis in children under 12 months of age correlated with development of secondary osteomyelitis [34,35]. Contrast has been shown to markedly improve detection of infection of unossified growth cartilage (chondritis) in children <6 years of age, in which the cartilage most commonly appeared normal on unenhanced sequences; hypoenhancement was more commonly noted with infection [36,37]. In one study of children <18 months of age with community acquired S aureus infection of the unossified epiphyseal cartilage, 7 of 9 cases demonstrated normal cartilage signal on noncontrast sequences; hypoenhancement or nonenhancement of involved foci was used for diagnosis [36]. In another study of children <6 years of age, focal or global cartilage nonenhancement was demonstrated in 71% of 14 patients with surgically confirmed epiphyseal osteomyelitis, compared with 21% of controls [37]. Global enhancement defects were more sensitive, noted in 43% of cases but not seen in any control cases. Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, IV contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis, and diminished femoral head enhancement on MRI has been noted in the setting of septic arthritis in children under 12 months of age correlated with development of secondary osteomyelitis [34,35]. Contrast has been shown to markedly improve detection of infection of unossified growth cartilage (chondritis) in children <6 years of age, in which the cartilage most commonly appeared normal on unenhanced sequences; hypoenhancement was more commonly noted with infection [36,37]. In one study of children <18 months of age with community acquired S aureus infection of the unossified epiphyseal cartilage, 7 of 9 cases demonstrated normal cartilage signal on noncontrast sequences; hypoenhancement or nonenhancement of involved foci was used for diagnosis [36]. In another study of children <6 years of age, focal or global cartilage nonenhancement was demonstrated in 71% of 14 patients with surgically confirmed epiphyseal osteomyelitis, compared with 21% of controls [37]. Global enhancement defects were more sensitive, noted in 43% of cases but not seen in any control cases. Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60].

3158175

acrac_3158175_9

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities; most common diagnoses included stress reaction, soft-tissue edema, myositis, sterile joint effusion, and leukemia. Osteomyelitis or Septic Arthritis-Child US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. Although some studies have shown no significant difference in sensitivity and specificity in diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection.

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities; most common diagnoses included stress reaction, soft-tissue edema, myositis, sterile joint effusion, and leukemia. Osteomyelitis or Septic Arthritis-Child US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. Although some studies have shown no significant difference in sensitivity and specificity in diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection.

3158175

acrac_3158175_10

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, though this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, >50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. Radiography Area of Interest Radiographs are not sensitive in assessment of early osteomyelitis because bone destruction does not typically occur until 7 to 10 days into the disease course, and radiographs are normal until >30% osseous matrix destruction has occurred [24,40]. Radiographs, however, do have utility in all populations in excluding other entities that may mimic acute osteomyelitis, such as fracture or neoplasm [3,25,31,40]. Radiographs are highly variable in identifying hip joint effusions, with sensitivity ranging from 20% to 73% [40,42,43]. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, though this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, >50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38]. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. Radiography Area of Interest Radiographs are not sensitive in assessment of early osteomyelitis because bone destruction does not typically occur until 7 to 10 days into the disease course, and radiographs are normal until >30% osseous matrix destruction has occurred [24,40]. Radiographs, however, do have utility in all populations in excluding other entities that may mimic acute osteomyelitis, such as fracture or neoplasm [3,25,31,40]. Radiographs are highly variable in identifying hip joint effusions, with sensitivity ranging from 20% to 73% [40,42,43]. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44].

3158175

acrac_3158175_11

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. Bone Scan Whole Body Whole-body bone scan is typically recommended when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54]. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole- body and selected static images, without blood flow or blood pool views [55]. Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. In another smaller study, 9 patients who underwent whole-body scan, Osteomyelitis or Septic Arthritis-Child 100% (7 of 7) patients with osteomyelitis had increased uptake corresponding to the site of involvement [56]. SPECT/CT offers improved characterization of osseous pathology compared to planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease [53]. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest Whole-body bone scan is typically recommended when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. Bone Scan Whole Body Whole-body bone scan is typically recommended when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54]. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole- body and selected static images, without blood flow or blood pool views [55]. Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. In another smaller study, 9 patients who underwent whole-body scan, Osteomyelitis or Septic Arthritis-Child 100% (7 of 7) patients with osteomyelitis had increased uptake corresponding to the site of involvement [56]. SPECT/CT offers improved characterization of osseous pathology compared to planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease [53]. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest Whole-body bone scan is typically recommended when scintigraphy is used for suspected osteomyelitis, particularly if there is a fever of unknown origin or bacteremia [54].

3158175

acrac_3158175_12

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

In one study of 213 children referred for skeletal scintigraphy because of a suspicion for acute hematogenous osteomyelitis who underwent a 3-phase bone scan of the area of interest along with whole-body delayed images, accurate diagnosis was made in 84% of cases without the need for MRI, including 92% of those diagnosed with osteomyelitis [57]. In another study of 65 children who underwent whole-body scan with focused evaluations of the area of interest and the contralateral side, 23 patients who were classified as having osteomyelitis all had abnormal bone scans [58]. SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease, but SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [53,59]. Image-Guided Aspiration Area of Interest Primary differential considerations when a joint effusion is present in the absence of trauma are transient synovitis and septic arthritis. Though most nontraumatic hip joint effusions are secondary to transient synovitis, early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate for diagnosis [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted than US guidance for aspiration was only provided in one case, and the remainder were performed using anatomic landmarks and without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US- guided joint aspiration experienced shorter duration of stay and shorter duration of a limp compared with those who did not undergo joint aspiration [61].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In one study of 213 children referred for skeletal scintigraphy because of a suspicion for acute hematogenous osteomyelitis who underwent a 3-phase bone scan of the area of interest along with whole-body delayed images, accurate diagnosis was made in 84% of cases without the need for MRI, including 92% of those diagnosed with osteomyelitis [57]. In another study of 65 children who underwent whole-body scan with focused evaluations of the area of interest and the contralateral side, 23 patients who were classified as having osteomyelitis all had abnormal bone scans [58]. SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [59]. MRI is generally considered preferable in detection of early manifestations of osteomyelitis, as well as infection of the surrounding soft tissues, because of the rapid progression of the disease, but SPECT/CT offers improved characterization of osseous pathology compared with planar imaging [53,59]. Image-Guided Aspiration Area of Interest Primary differential considerations when a joint effusion is present in the absence of trauma are transient synovitis and septic arthritis. Though most nontraumatic hip joint effusions are secondary to transient synovitis, early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate for diagnosis [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted than US guidance for aspiration was only provided in one case, and the remainder were performed using anatomic landmarks and without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US- guided joint aspiration experienced shorter duration of stay and shorter duration of a limp compared with those who did not undergo joint aspiration [61].

3158175

acrac_3158175_13

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63]. Although the bulk of literature on image-guided joint aspiration in the pediatric population refers to the hip joint, aspiration could also be considered in other joints. Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection. In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, although this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, over 50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60]. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63]. Although the bulk of literature on image-guided joint aspiration in the pediatric population refers to the hip joint, aspiration could also be considered in other joints. Although some studies have shown no significant difference in sensitivity and specificity in the diagnosis of osteomyelitis or septic arthritis with or without the use of gadolinium-based contrast agents, contrast has been shown to improve detection of abscesses [32,33]. Decreased femoral head enhancement on early postcontrast imaging has been noted as a reliable feature of septic arthritis not seen in transient synovitis [34]. In addition, MRI has been shown to be useful in evaluating for concurrent musculoskeletal infection. In assessment of septic arthritis, the majority of pediatric patients with septic arthritis were noted on MRI to have infection beyond the joint space, although this may vary based on population factors such as geography [7,46,60,65,66]. Conversely, in metaphyseal osteomyelitis, over 50% in one study were noted on MRI to have concomitant joint effusions, 75% of which were confirmed to be septic arthritis [67]. Osteomyelitis or Septic Arthritis-Child Repeat MRI of the area of interest performed for worsening or persistent symptoms resulted in clinical management changes in 21% of patients [64]. In one study on septic elbow arthritis, 40% of patients did not respond to antibiotic therapy and were noted on subsequent elbow MRI to have concurrent osteomyelitis [60]. MRI Extremity Area of Interest In one study, a large field-of-view MRI was performed to encompass both lower extremities rather than the area of concern [38].

3158175

acrac_3158175_14

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. 3-Phase Bone Scan Area of Interest There is limited data regarding the use of 3-phase bone scan of area of interest as the next imaging study in evaluation of septic arthritis. In one study in which blood pool and delayed imaging of only the area of interest were performed, 8 of 9 cases of septic arthritis were identified [51]. Bone Scan Whole Body There is limited data regarding the use of whole-body bone scan as the next imaging study in the evaluation of septic arthritis. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. In patients who were later found to have osteomyelitis, 11% had contralateral extremity findings, including contralateral osteomyelitis, and 20% had ipsilateral septic arthritis. Among patients who did not have osteomyelitis, 20% had contralateral abnormalities, most commonly stress reaction, soft-tissue edema, myositis, joint effusion (not septic), and leukemia. US Area of Interest US is a highly sensitive method of diagnosing hip joint effusion, and the absence of hip joint effusion virtually excludes septic arthritis; a false negative rate of 5% has been described, noted in patients with a shorter duration of symptoms (<1 day) [40,43,45-47]. US can reportedly detect hip effusions as small as 1 mL [44]. Hip US for the purpose of identifying joint effusion can be performed with high sensitivity and specificity [48]. In one study, nearly 80% of pediatric patients with hip septic arthritis required US imaging alone to guide their management [45]. US in evaluation of osteomyelitis is limited in its ability to assess the osseous structures but can identify abutting inflammatory changes affecting the soft tissues such as periosteal elevation and subperiosteal collections [40,49,50]. 3-Phase Bone Scan Area of Interest There is limited data regarding the use of 3-phase bone scan of area of interest as the next imaging study in evaluation of septic arthritis. In one study in which blood pool and delayed imaging of only the area of interest were performed, 8 of 9 cases of septic arthritis were identified [51]. Bone Scan Whole Body There is limited data regarding the use of whole-body bone scan as the next imaging study in the evaluation of septic arthritis. One study assessed the accuracy of bone scan for the diagnosis of suspected acute hematogenous osteomyelitis and septic arthritis in 86 children, using whole-body and selected static images, without blood flow or blood pool views [55].

3158175

acrac_3158175_15

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs

Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest There is no relevant recent regarding the use of whole-body bone scan and 3-phase bone scan of area of interest as the next imaging study in the evaluation of suspected septic arthritis. CT Area of Interest There is no relevant literature regarding the use of CT as the next imaging study in the evaluation of suspected septic arthritis. Image-Guided Aspiration Area of Interest Early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted that US guidance for Osteomyelitis or Septic Arthritis-Child aspiration was only provided in one case, and the remainder performed using anatomic landmarks without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US-guided joint aspiration experienced shorter duration of stay and shorter duration of limp compared with those who did not undergo joint aspiration [61]. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63].

Osteomyelitis or Septic Arthritis Child Excluding Axial Skeleton PCAs. Bone scan findings were correlated with the final diagnosis in 34 sites of septic arthritis and in 62 sites of osteomyelitis. Bone scan accuracy was 81%. Positive predictive value was 82% for those sites with increased activity and 100% for those sites with decreased activity. Negative predictive value was 63%. Bone Scan Whole Body and 3-Phase Bone Scan Area of Interest There is no relevant recent regarding the use of whole-body bone scan and 3-phase bone scan of area of interest as the next imaging study in the evaluation of suspected septic arthritis. CT Area of Interest There is no relevant literature regarding the use of CT as the next imaging study in the evaluation of suspected septic arthritis. Image-Guided Aspiration Area of Interest Early diagnosis of septic arthritis is extremely important in preventing complications, and US-guided hip aspiration is considered highly accurate [43,61]. In one study, 100% of children were confirmed to have septic hip arthritis via bedside joint aspiration and were able to avoid arthrotomy. However, it should be noted that US guidance for Osteomyelitis or Septic Arthritis-Child aspiration was only provided in one case, and the remainder performed using anatomic landmarks without imaging guidance [62]. In the setting of confirmed transient synovitis, children who underwent US-guided joint aspiration experienced shorter duration of stay and shorter duration of limp compared with those who did not undergo joint aspiration [61]. In patients with suspected or confirmed septic arthritis, femoral neck aspiration performed at the time of incision and drainage was noted to improve diagnosis of concurrent osteomyelitis compared with preoperative MRI alone [63].

3158175

acrac_69482_0

Headache PCAs

Initial Imaging Definition Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when: aColumbia University Medical Center, New York, New York. bPanel Chair, Uniformed Services University, Bethesda, Maryland. cOhio State University, Columbus, Ohio. dWake Forest School of Medicine, Winston Salem, North Carolina; American Geriatrics Society. eStanford University, Stanford, California, Primary care physician. fIndiana University School of Medicine, Indianapolis, Indiana; Committee on Emergency Radiology-GSER. gMayo Clinic, Rochester, Minnesota; Commission on Nuclear Medicine and Molecular Imaging. hWeill Cornell Medical College, New York, New York. iUniversity of California Los Angeles, Los Angeles, California. jEinstein Healthcare Network, Philadelphia, Pennsylvania. kFort Belvoir Community Hospital, Fort Belvoir, Virginia; American Academy of Family Physicians. lUniversity of California San Diego, San Diego, California. mOregon Health & Science University, Portland, Oregon. nSouthern California Permanente Medical Group, Pasadena, California; American Academy of Neurology. oWeill Cornell Medical College, New York, New York; American Academy of Otolaryngology-Head and Neck Surgery. pSchmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida; American College of Emergency Physicians. qThe University of Vermont Medical Center, Burlington, Vermont. rOakland University William Beaumont School of Medicine, Rochester, Michigan; American Association of Neurological Surgeons/Congress of Neurological Surgeons. sUniversity of Cincinnati Medical Center, Cincinnati, Ohio. tSpecialty Chair, Montefiore Medical Center, Bronx, New York.

Headache PCAs. Initial Imaging Definition Initial imaging is defined as imaging at the beginning of the care episode for the medical condition defined by the variant. More than one procedure can be considered usually appropriate in the initial imaging evaluation when: aColumbia University Medical Center, New York, New York. bPanel Chair, Uniformed Services University, Bethesda, Maryland. cOhio State University, Columbus, Ohio. dWake Forest School of Medicine, Winston Salem, North Carolina; American Geriatrics Society. eStanford University, Stanford, California, Primary care physician. fIndiana University School of Medicine, Indianapolis, Indiana; Committee on Emergency Radiology-GSER. gMayo Clinic, Rochester, Minnesota; Commission on Nuclear Medicine and Molecular Imaging. hWeill Cornell Medical College, New York, New York. iUniversity of California Los Angeles, Los Angeles, California. jEinstein Healthcare Network, Philadelphia, Pennsylvania. kFort Belvoir Community Hospital, Fort Belvoir, Virginia; American Academy of Family Physicians. lUniversity of California San Diego, San Diego, California. mOregon Health & Science University, Portland, Oregon. nSouthern California Permanente Medical Group, Pasadena, California; American Academy of Neurology. oWeill Cornell Medical College, New York, New York; American Academy of Otolaryngology-Head and Neck Surgery. pSchmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida; American College of Emergency Physicians. qThe University of Vermont Medical Center, Burlington, Vermont. rOakland University William Beaumont School of Medicine, Rochester, Michigan; American Association of Neurological Surgeons/Congress of Neurological Surgeons. sUniversity of Cincinnati Medical Center, Cincinnati, Ohio. tSpecialty Chair, Montefiore Medical Center, Bronx, New York.

69482

acrac_69482_1

Headache PCAs

The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org OR Headache Discussion of Procedures by Variant Variant 1: Sudden onset severe headache that reaches maximal severity within one hour. Initial imaging. Many of the headaches presenting to the emergency department are benign or primary; however, a subset of headaches defined as TCH warrant further investigation. The most important feature of TCH is the abrupt onset of a severe headache that reaches maximum intensity in <1 minute, although for the purposes of this discussion, the term will be used more loosely to encompass the sudden onset of a severe headache that reaches maximum intensity in <1 hour. Initially used in reference to the pain associated with leaking or ruptured intracranial aneurysms, other etiologies of TCH have since been identified [10,11]. Ruptured aneurysm resulting in subarachnoid hemorrhage (SAH) is the primary concern because of significant morbidity and mortality, although it accounts for only 4% to 12% of acute severe headaches [11]. Reversible cerebral vasoconstriction syndrome (RCVS) is the second most common cause of TCH and is the most common cause of TCH without aneurysmal SAH. Associated complications include intracranial hemorrhage and ischemic infarction [12]. RCVS is an important cause of recurrent TCH; half of RCVS headaches can be attributed to a specific trigger [10,12].

Headache PCAs. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org OR Headache Discussion of Procedures by Variant Variant 1: Sudden onset severe headache that reaches maximal severity within one hour. Initial imaging. Many of the headaches presenting to the emergency department are benign or primary; however, a subset of headaches defined as TCH warrant further investigation. The most important feature of TCH is the abrupt onset of a severe headache that reaches maximum intensity in <1 minute, although for the purposes of this discussion, the term will be used more loosely to encompass the sudden onset of a severe headache that reaches maximum intensity in <1 hour. Initially used in reference to the pain associated with leaking or ruptured intracranial aneurysms, other etiologies of TCH have since been identified [10,11]. Ruptured aneurysm resulting in subarachnoid hemorrhage (SAH) is the primary concern because of significant morbidity and mortality, although it accounts for only 4% to 12% of acute severe headaches [11]. Reversible cerebral vasoconstriction syndrome (RCVS) is the second most common cause of TCH and is the most common cause of TCH without aneurysmal SAH. Associated complications include intracranial hemorrhage and ischemic infarction [12]. RCVS is an important cause of recurrent TCH; half of RCVS headaches can be attributed to a specific trigger [10,12].

69482

acrac_69482_2

Headache PCAs

Less common causes of TCH include cerebral venous thrombosis (CVT), cervical arterial dissection, posterior reversible encephalopathy syndrome (PRES), spontaneous intracranial hypotension (SIH), pituitary apoplexy, perimesencephalic hemorrhage, arteriovenous malformations (AVM), dural arteriovenous fistulas, and intraventricular colloid cyst. A subset of patients will not have a causative disorder and will be diagnosed as suffering from primary TCH; this is a diagnosis of exclusion [10,11,13]. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Digital subtraction angiography (DSA) can assess vessel diameters as small as 0.4 mm compared with 0.7 mm for CT angiography (CTA). This may be useful for further workup of etiologies such as RCVS, which primarily impacts the smaller vessels and provides the opportunity for intravascular therapy. For example, intraarterial nimodipine has been used to demonstrate reversibility, a diagnostic criterion for RCVS [12]. Likewise, DSA may have a role in the workup of aneurysm rupture associated with SAH, when no aneurysm is detected on the initial multidetector CTA. The American Heart Association and the American Stroke Association guidelines also suggest that DSA may not be necessary if a classic perimesencephalic pattern of hemorrhage is present on CT with a negative CTA. In cases of suspected CVT or AVM based on initial neuroimaging, catheter angiography may be used for further characterization and for endovascular therapy [11]. CT Head With IV Contrast There is no relevant literature to support the use of CT head with intravenous (IV) contrast in the initial imaging evaluation of TCH. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of TCH. Headache

Headache PCAs. Less common causes of TCH include cerebral venous thrombosis (CVT), cervical arterial dissection, posterior reversible encephalopathy syndrome (PRES), spontaneous intracranial hypotension (SIH), pituitary apoplexy, perimesencephalic hemorrhage, arteriovenous malformations (AVM), dural arteriovenous fistulas, and intraventricular colloid cyst. A subset of patients will not have a causative disorder and will be diagnosed as suffering from primary TCH; this is a diagnosis of exclusion [10,11,13]. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Digital subtraction angiography (DSA) can assess vessel diameters as small as 0.4 mm compared with 0.7 mm for CT angiography (CTA). This may be useful for further workup of etiologies such as RCVS, which primarily impacts the smaller vessels and provides the opportunity for intravascular therapy. For example, intraarterial nimodipine has been used to demonstrate reversibility, a diagnostic criterion for RCVS [12]. Likewise, DSA may have a role in the workup of aneurysm rupture associated with SAH, when no aneurysm is detected on the initial multidetector CTA. The American Heart Association and the American Stroke Association guidelines also suggest that DSA may not be necessary if a classic perimesencephalic pattern of hemorrhage is present on CT with a negative CTA. In cases of suspected CVT or AVM based on initial neuroimaging, catheter angiography may be used for further characterization and for endovascular therapy [11]. CT Head With IV Contrast There is no relevant literature to support the use of CT head with intravenous (IV) contrast in the initial imaging evaluation of TCH. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of TCH. Headache

69482

acrac_69482_3

Headache PCAs

CT Head Without IV Contrast CT head without IV contrast is useful in the setting of TCH because of its high sensitivity for detecting intracranial hemorrhage. Several studies have demonstrated a high negative predictive value of a noncontrast head CT performed within 6 hours of headache onset in detecting aneurysmal SAH, ranging between 99.9% and 100%. When it is performed within the first 24 hours, the sensitivity ranges between 90% and 100% [16,17]. Ten percent of patients with CVT present with SAH; associated CT abnormalities include venous infarcts, parenchymal edema, or hyperdense thrombus within the occluded sinus. Although SAH is less common in cases of ruptured AVMs, lobar hemorrhage and serpiginous structures representing dilated vasculature can be seen on a noncontrast head CT [11]. In addition, a CTA head with IV contrast may be useful in the setting of TCH when performed in conjunction with a noncontrast head CT (not as an independent initial imaging technique in isolation). There is literature supporting the usefulness of obtaining a head CTA at the same time as a head CT in a patient with TCH, especially when a patient presents with sudden onset severe headache >6 hours, because the sensitivity of head CT for SAH diminishes over time. For suspected cases of RCVS, a noncontrast head CT with special attention to the presence of convexity SAH has been shown to be useful [12] CTA Head With IV Contrast CTA head with IV contrast may be useful in the setting of TCH when performed in conjunction with a noncontrast head CT (not as an independent initial imaging technique in isolation). There is literature supporting the usefulness of obtaining a head CTA at the same time as a head CT in a patient with TCH, especially when a patient presents with sudden onset severe headache >6 hours, because the sensitivity of head CT for SAH diminishes over time.

Headache PCAs. CT Head Without IV Contrast CT head without IV contrast is useful in the setting of TCH because of its high sensitivity for detecting intracranial hemorrhage. Several studies have demonstrated a high negative predictive value of a noncontrast head CT performed within 6 hours of headache onset in detecting aneurysmal SAH, ranging between 99.9% and 100%. When it is performed within the first 24 hours, the sensitivity ranges between 90% and 100% [16,17]. Ten percent of patients with CVT present with SAH; associated CT abnormalities include venous infarcts, parenchymal edema, or hyperdense thrombus within the occluded sinus. Although SAH is less common in cases of ruptured AVMs, lobar hemorrhage and serpiginous structures representing dilated vasculature can be seen on a noncontrast head CT [11]. In addition, a CTA head with IV contrast may be useful in the setting of TCH when performed in conjunction with a noncontrast head CT (not as an independent initial imaging technique in isolation). There is literature supporting the usefulness of obtaining a head CTA at the same time as a head CT in a patient with TCH, especially when a patient presents with sudden onset severe headache >6 hours, because the sensitivity of head CT for SAH diminishes over time. For suspected cases of RCVS, a noncontrast head CT with special attention to the presence of convexity SAH has been shown to be useful [12] CTA Head With IV Contrast CTA head with IV contrast may be useful in the setting of TCH when performed in conjunction with a noncontrast head CT (not as an independent initial imaging technique in isolation). There is literature supporting the usefulness of obtaining a head CTA at the same time as a head CT in a patient with TCH, especially when a patient presents with sudden onset severe headache >6 hours, because the sensitivity of head CT for SAH diminishes over time.

69482

acrac_69482_4

Headache PCAs

For example, a concurrent or follow-up CTA is useful in suspected cases of intracranial aneurysm (ruptured or unruptured), arterial dissection, and RCVS [10-12,18]. CTV Head With IV Contrast There is no relevant literature to support the use of CT venography (CTV) head with IV contrast in the initial imaging evaluation of TCH. Following initial evaluation with a noncontrast head CT, head CTV can be useful when there are clinical or imaging findings suspicious for CVT, which is a less common cause of TCH [11,13]. MRA Head With IV Contrast There is no relevant literature to support the use of MR angiography (MRA) head with IV contrast in the initial imaging evaluation of TCH. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of TCH. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of TCH. However, similar to head CTA, brain MRA can be obtained as a follow-up imaging study when there are clinical or imaging findings concerning for aneurysm, dissection, RCVS, or AVM [11]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of TCH. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Contrast-enhanced brain MRI can be useful in the diagnosis of SIH, pituitary apoplexy, and intraventricular colloid cyst, which are rare causes of TCH [11]. High-resolution MRI using vessel wall imaging may be useful in differentiating various vasculitides from RCVS and in identifying dissection of the intracranial vessels, compared with standard MRI.

Headache PCAs. For example, a concurrent or follow-up CTA is useful in suspected cases of intracranial aneurysm (ruptured or unruptured), arterial dissection, and RCVS [10-12,18]. CTV Head With IV Contrast There is no relevant literature to support the use of CT venography (CTV) head with IV contrast in the initial imaging evaluation of TCH. Following initial evaluation with a noncontrast head CT, head CTV can be useful when there are clinical or imaging findings suspicious for CVT, which is a less common cause of TCH [11,13]. MRA Head With IV Contrast There is no relevant literature to support the use of MR angiography (MRA) head with IV contrast in the initial imaging evaluation of TCH. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of TCH. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of TCH. However, similar to head CTA, brain MRA can be obtained as a follow-up imaging study when there are clinical or imaging findings concerning for aneurysm, dissection, RCVS, or AVM [11]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of TCH. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Contrast-enhanced brain MRI can be useful in the diagnosis of SIH, pituitary apoplexy, and intraventricular colloid cyst, which are rare causes of TCH [11]. High-resolution MRI using vessel wall imaging may be useful in differentiating various vasculitides from RCVS and in identifying dissection of the intracranial vessels, compared with standard MRI.

69482

acrac_69482_5

Headache PCAs

For example, recent studies have demonstrated concentric thickening of the vessel wall with minimal or no enhancement in RCVS, compared with more eccentric wall thickening and significant wall enhancement in cases of vasculitis [12]. In addition, vessel wall imaging can be used to help identify the ruptured lesion when initial CTA reveals multiple aneurysms [11]. Headache MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Brain MRI has been shown to have high sensitivity for SAH when using fluid-attenuated inversion recovery (FLAIR) and T2* or susceptibility-weighted images, especially in the acute phase. FLAIR has been demonstrated to be useful for detecting peripheral or sulcal SAH, and T2* has been demonstrated to be useful for detecting cisternal or intraventricular hemorrhage. However, other studies have identified additional causes of sulcal FLAIR hyperintensity, which is therefore not a specific finding for SAH. Brain MRI has higher contrast resolution than head CT, and as a follow-up examination, it can help delineate parenchymal changes from various other non-SAH etiologies of TCH including RCVS, CVT, and pituitary apoplexy [13,19,20]. MRV Head With IV Contrast There is no relevant literature to support the use of MR venography (MRV) head with IV contrast in the initial imaging evaluation of TCH. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of TCH. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of TCH.

Headache PCAs. For example, recent studies have demonstrated concentric thickening of the vessel wall with minimal or no enhancement in RCVS, compared with more eccentric wall thickening and significant wall enhancement in cases of vasculitis [12]. In addition, vessel wall imaging can be used to help identify the ruptured lesion when initial CTA reveals multiple aneurysms [11]. Headache MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of TCH; it may have utility in follow-up evaluation after initial neuroimaging. Brain MRI has been shown to have high sensitivity for SAH when using fluid-attenuated inversion recovery (FLAIR) and T2* or susceptibility-weighted images, especially in the acute phase. FLAIR has been demonstrated to be useful for detecting peripheral or sulcal SAH, and T2* has been demonstrated to be useful for detecting cisternal or intraventricular hemorrhage. However, other studies have identified additional causes of sulcal FLAIR hyperintensity, which is therefore not a specific finding for SAH. Brain MRI has higher contrast resolution than head CT, and as a follow-up examination, it can help delineate parenchymal changes from various other non-SAH etiologies of TCH including RCVS, CVT, and pituitary apoplexy [13,19,20]. MRV Head With IV Contrast There is no relevant literature to support the use of MR venography (MRV) head with IV contrast in the initial imaging evaluation of TCH. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of TCH. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of TCH.

69482

acrac_69482_6

Headache PCAs

Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. Variant 2: Primary migraine or tension-type headache. Normal neurologic examination. Initial imaging. In a single year, more than half of the adult population suffers from a headache, most often a primary headache such as TTH and migraine, with a prevalence of 21% and 15%, respectively [21]. Based on the 2016 Global Burden of Diseases study, TTHs and migraines have been ranked in the top 10 causes, with the greatest prevalence. Moreover, migraines are ranked as the second leading cause of years living with disability, especially in high- income, high-middle-income, and middle-socio-demographic index quintile countries. Migraine was also ranked as the second leading cause of years living with disability for women in 35 countries [22]. Two major types of migraines are documented: migraine with aura and migraine without aura. Although less disabling than migraine, TTH has a higher lifetime prevalence of 30% to 78% and, therefore, a high socioeconomic impact. The clinical criteria classify TTH into subtypes based on the frequency of headaches (number of days per month) and the presence or absence of pericranial tenderness [23]. Despite the clinical and social impact of the 2 most common primary headaches, various studies have demonstrated very few significant structural abnormalities on neuroimaging in patients presenting to the emergency department and outpatient clinics. The HUNT MRI study performed in middle-aged patients demonstrated that headache sufferers in general demonstrated an increased incidence of intracranial abnormalities, mostly attributed to small nonspecific white matter hyperintensities. This association was near zero when white matter hyperintensities were removed from the analysis [21]. Studies were also conducted examining the incidence of intracranial abnormalities in patients suffering from migraine with and without aura.

Headache PCAs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT [11]. Variant 2: Primary migraine or tension-type headache. Normal neurologic examination. Initial imaging. In a single year, more than half of the adult population suffers from a headache, most often a primary headache such as TTH and migraine, with a prevalence of 21% and 15%, respectively [21]. Based on the 2016 Global Burden of Diseases study, TTHs and migraines have been ranked in the top 10 causes, with the greatest prevalence. Moreover, migraines are ranked as the second leading cause of years living with disability, especially in high- income, high-middle-income, and middle-socio-demographic index quintile countries. Migraine was also ranked as the second leading cause of years living with disability for women in 35 countries [22]. Two major types of migraines are documented: migraine with aura and migraine without aura. Although less disabling than migraine, TTH has a higher lifetime prevalence of 30% to 78% and, therefore, a high socioeconomic impact. The clinical criteria classify TTH into subtypes based on the frequency of headaches (number of days per month) and the presence or absence of pericranial tenderness [23]. Despite the clinical and social impact of the 2 most common primary headaches, various studies have demonstrated very few significant structural abnormalities on neuroimaging in patients presenting to the emergency department and outpatient clinics. The HUNT MRI study performed in middle-aged patients demonstrated that headache sufferers in general demonstrated an increased incidence of intracranial abnormalities, mostly attributed to small nonspecific white matter hyperintensities. This association was near zero when white matter hyperintensities were removed from the analysis [21]. Studies were also conducted examining the incidence of intracranial abnormalities in patients suffering from migraine with and without aura.

69482

acrac_69482_7

Headache PCAs

It was found that patients with migraine with aura were imaged more frequently and demonstrated an increased incidence of minor intracranial abnormalities such as lacunar infarcts and microvascular ischemic changes. No abnormalities were detected that were of major clinical significance [24]. A study performed in China in 2018 examined 1,070 healthy control patients and 1,070 primary headache sufferers; imaging evaluation included either CT or MRI and found no statistical difference in the detection of intracranial abnormalities: 0.58% in patients with headache and 0.78% in healthy controls [25]. Headache Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Most studies demonstrate a very low incidence of clinically significant intracranial abnormalities in patients presenting with migraine or TTH and a normal neurological examination [25,26]. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination.

Headache PCAs. It was found that patients with migraine with aura were imaged more frequently and demonstrated an increased incidence of minor intracranial abnormalities such as lacunar infarcts and microvascular ischemic changes. No abnormalities were detected that were of major clinical significance [24]. A study performed in China in 2018 examined 1,070 healthy control patients and 1,070 primary headache sufferers; imaging evaluation included either CT or MRI and found no statistical difference in the detection of intracranial abnormalities: 0.58% in patients with headache and 0.78% in healthy controls [25]. Headache Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Most studies demonstrate a very low incidence of clinically significant intracranial abnormalities in patients presenting with migraine or TTH and a normal neurological examination [25,26]. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination.

69482

acrac_69482_8

Headache PCAs

CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Brain MRA in primary patients with headache has demonstrated no increased incidence of vascular abnormalities [21]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Several studies in primary headache sufferers demonstrated no significant increase in the incidence of major intracranial abnormalities that would require further action or are clinically significant. The most prevalent findings were an increased incidence of small nonspecific white matter hyperintensities, especially in TTH [21,24-26].

Headache PCAs. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Brain MRA in primary patients with headache has demonstrated no increased incidence of vascular abnormalities [21]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Several studies in primary headache sufferers demonstrated no significant increase in the incidence of major intracranial abnormalities that would require further action or are clinically significant. The most prevalent findings were an increased incidence of small nonspecific white matter hyperintensities, especially in TTH [21,24-26].

69482

acrac_69482_9

Headache PCAs

Imaging techniques continue to evolve and improve, and recent developments in advanced MRI techniques are allowing the clinical community to better understand the underlying pathophysiology of migraines, which remains less well characterized than the clinical phenotype. Early research with novel structural imaging techniques such as voxel based morphometry and surface based morphometry suggest consistent variations in gray matter volume in regions of the brain responsible for pain processing and modulation in patients with migraine and other chronic Headache pain. White matter hyperintensities have been the most common minor intracranial abnormality in patients with migraine. Recent studies have investigated the correlation of white matter volume changes (eg, corpus callosum) and microstructural alterations on diffusion tensor imaging to symptoms in patients with migraine with and without aura, especially those with a depressive/anxious comorbidity. Functional neuroimaging studies have also been used to investigate the brain activation changes during and between migraine attacks. In addition to functional imaging, research using arterial spin labeling imaging to measure perfusion without necessitating IV contrast is providing useful insignts into the transient perfusion changes during the acute phase of an aura and following an attack. Arterial spin labeling has also proved in separating mirgraine with aura from cerebral ischemia, which can have a direct impact on clinical decision making. This ongoing research may help us understand attack ignition/propagation and provide targets for future therapy [27,28]. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination.

Headache PCAs. Imaging techniques continue to evolve and improve, and recent developments in advanced MRI techniques are allowing the clinical community to better understand the underlying pathophysiology of migraines, which remains less well characterized than the clinical phenotype. Early research with novel structural imaging techniques such as voxel based morphometry and surface based morphometry suggest consistent variations in gray matter volume in regions of the brain responsible for pain processing and modulation in patients with migraine and other chronic Headache pain. White matter hyperintensities have been the most common minor intracranial abnormality in patients with migraine. Recent studies have investigated the correlation of white matter volume changes (eg, corpus callosum) and microstructural alterations on diffusion tensor imaging to symptoms in patients with migraine with and without aura, especially those with a depressive/anxious comorbidity. Functional neuroimaging studies have also been used to investigate the brain activation changes during and between migraine attacks. In addition to functional imaging, research using arterial spin labeling imaging to measure perfusion without necessitating IV contrast is providing useful insignts into the transient perfusion changes during the acute phase of an aura and following an attack. Arterial spin labeling has also proved in separating mirgraine with aura from cerebral ischemia, which can have a direct impact on clinical decision making. This ongoing research may help us understand attack ignition/propagation and provide targets for future therapy [27,28]. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination.

69482

acrac_69482_10

Headache PCAs

MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Variant 3: Primary trigeminal autonomic cephalalgias (eg, cluster headache). Initial imaging. The ICHD-3 describes TACs as attacks of severe, strictly unilateral pain, which are orbital, supraorbital, temporal, or in any combination of these sites, lasting 15 to 180 minutes and occurring from once every other day to 8 times a day. Associated symptoms include ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhea, forehead and facial sweating, miosis, ptosis and/or eyelid edema, with or without restlessness or agitation. This predilection for the ophthalmic nerve (V1) distribution and associated autonomic symptoms help differentiate TACs from trigeminal neuralgia, which is a different disease. They are further classified as chronic or episodic, with 10% to 15% of patients suffering from chronic cluster headaches. Other subtypes include paroxysmal hemicranias (2-30 minutes), short-lasting unilateral neuralgiform headache attacks (1-600 seconds), hemicrania continua, and probable TAC. The short-lasting unilateral headache attacks are further characterized in 2 types: short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms [23]. TACs are, as a group, an uncommon primary headache disorder, with cluster headaches being the most common, characterized by a prevalence of 0.1% to 0.4% and a male predominance [29,30].

Headache PCAs. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of primary migraine or TTH with a normal neurologic examination. Variant 3: Primary trigeminal autonomic cephalalgias (eg, cluster headache). Initial imaging. The ICHD-3 describes TACs as attacks of severe, strictly unilateral pain, which are orbital, supraorbital, temporal, or in any combination of these sites, lasting 15 to 180 minutes and occurring from once every other day to 8 times a day. Associated symptoms include ipsilateral conjunctival injection, lacrimation, nasal congestion, rhinorrhea, forehead and facial sweating, miosis, ptosis and/or eyelid edema, with or without restlessness or agitation. This predilection for the ophthalmic nerve (V1) distribution and associated autonomic symptoms help differentiate TACs from trigeminal neuralgia, which is a different disease. They are further classified as chronic or episodic, with 10% to 15% of patients suffering from chronic cluster headaches. Other subtypes include paroxysmal hemicranias (2-30 minutes), short-lasting unilateral neuralgiform headache attacks (1-600 seconds), hemicrania continua, and probable TAC. The short-lasting unilateral headache attacks are further characterized in 2 types: short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms [23]. TACs are, as a group, an uncommon primary headache disorder, with cluster headaches being the most common, characterized by a prevalence of 0.1% to 0.4% and a male predominance [29,30].

69482

acrac_69482_11

Headache PCAs

The exact pathophysiology of TACs is not well understood; current investigations suggest the involvement of the trigeminovascular system, the autonomic nervous system, and the hypothalamus. Recent functional and anatomic neuroimaging studies have demonstrated changes in the pain neuromatrix including the trigeminal nerve, trigeminovascular complex, and general pain system [30]. TACs are a primary headache disorder; however, the differential diagnosis includes structural lesions affecting the trigeminal autonomic reflex and pain pathways. Therefore, it is usually recommended to rule out a secondary cause of these headaches with neuroimaging. The most common structural lesions are primary pituitary lesions. Other reported lesions include parasellar meningiomas, posterior fossa lesions, vascular lesions such as carotid or vertebral artery dissection, cerebral AVMs, and sinus infections. Possible underlying causes of hemicrania continua include CVT and intracranial metastases [30-33]. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of TACs. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of TACs. Headache CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of TACs. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of TACs. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of TACs; it may have utility in follow-up evaluation after initial neuroimaging. Vascular lesions including carotid/vertebral dissections, AVMs, and aneurysms are a rare, secondary cause of TACs [30,31,33].

Headache PCAs. The exact pathophysiology of TACs is not well understood; current investigations suggest the involvement of the trigeminovascular system, the autonomic nervous system, and the hypothalamus. Recent functional and anatomic neuroimaging studies have demonstrated changes in the pain neuromatrix including the trigeminal nerve, trigeminovascular complex, and general pain system [30]. TACs are a primary headache disorder; however, the differential diagnosis includes structural lesions affecting the trigeminal autonomic reflex and pain pathways. Therefore, it is usually recommended to rule out a secondary cause of these headaches with neuroimaging. The most common structural lesions are primary pituitary lesions. Other reported lesions include parasellar meningiomas, posterior fossa lesions, vascular lesions such as carotid or vertebral artery dissection, cerebral AVMs, and sinus infections. Possible underlying causes of hemicrania continua include CVT and intracranial metastases [30-33]. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of TACs. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of TACs. Headache CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of TACs. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of TACs. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of TACs; it may have utility in follow-up evaluation after initial neuroimaging. Vascular lesions including carotid/vertebral dissections, AVMs, and aneurysms are a rare, secondary cause of TACs [30,31,33].

69482

acrac_69482_12

Headache PCAs

The European Headache Federation recommends vascular imaging especially when 3 consecutive preventative treatments fail [34]. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of TACs. Brain CTV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua. [30,31,33,34]. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of TACs. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of TACs. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of TACs; it may have utility in follow-up evaluation after initial neuroimaging. Vascular lesions including carotid/vertebral dissections, AVMs, and aneurysms are a rare, secondary cause of TACs [30,31,33]. The European Headache Federation recommends vascular imaging especially when 3 consecutive preventative treatments fail [34]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of TACs; the most common recommendation for initial imaging evaluation is MRI head without and with IV contrast. MRI Head Without and With IV Contrast MRI head without and with IV contrast is the most common recommendation for initial imaging evaluation of TACs; it is useful to help exclude a secondary headache due to a sellar region or posterior fossa mass. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of TACs; the most common recommendation for initial imaging evaluation is MRI head without and with IV contrast.

Headache PCAs. The European Headache Federation recommends vascular imaging especially when 3 consecutive preventative treatments fail [34]. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of TACs. Brain CTV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua. [30,31,33,34]. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of TACs. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of TACs. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of TACs; it may have utility in follow-up evaluation after initial neuroimaging. Vascular lesions including carotid/vertebral dissections, AVMs, and aneurysms are a rare, secondary cause of TACs [30,31,33]. The European Headache Federation recommends vascular imaging especially when 3 consecutive preventative treatments fail [34]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of TACs; the most common recommendation for initial imaging evaluation is MRI head without and with IV contrast. MRI Head Without and With IV Contrast MRI head without and with IV contrast is the most common recommendation for initial imaging evaluation of TACs; it is useful to help exclude a secondary headache due to a sellar region or posterior fossa mass. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of TACs; the most common recommendation for initial imaging evaluation is MRI head without and with IV contrast.

69482

acrac_69482_13

Headache PCAs

Headache MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. Variant 4: Headache with features of intracranial hypertension (eg, papilledema, pulsatile tinnitus, visual symptoms worse on Valsalva). Initial imaging. Headache attributed to increased cerebrospinal fluid (CSF) pressure can be accompanied by nausea/vomiting and exacerbated by the Valsalva maneuver (inhibits venous return) or by lying down (redistributes CSF into head). Elevated intracranial pressure can be due to various secondary etiologies such as structural lesions including mass, hydrocephalus, and venous sinus thrombosis [35]. Primary idiopathic intracranial hypertension (IIH), also known previously as pseudotumor cerebri, is characterized as an elevation of intracranial pressure with no identifiable cause. The etiology remains unknown. IIH predominantly impacts women, especially obese women of childbearing age. The prevalence of IIH in the general population ranges between 0.5 and 2 per 100,000. Due to the overlap of symptoms with several other primary headache syndromes, IIH is likely underdiagnosed.

Headache PCAs. Headache MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of TACs. Brain MRV can be used as a follow-up imaging study in cases of suspected CVT, which is in the differential diagnosis for TACs, especially hemicrania continua [30,31,33,34]. Variant 4: Headache with features of intracranial hypertension (eg, papilledema, pulsatile tinnitus, visual symptoms worse on Valsalva). Initial imaging. Headache attributed to increased cerebrospinal fluid (CSF) pressure can be accompanied by nausea/vomiting and exacerbated by the Valsalva maneuver (inhibits venous return) or by lying down (redistributes CSF into head). Elevated intracranial pressure can be due to various secondary etiologies such as structural lesions including mass, hydrocephalus, and venous sinus thrombosis [35]. Primary idiopathic intracranial hypertension (IIH), also known previously as pseudotumor cerebri, is characterized as an elevation of intracranial pressure with no identifiable cause. The etiology remains unknown. IIH predominantly impacts women, especially obese women of childbearing age. The prevalence of IIH in the general population ranges between 0.5 and 2 per 100,000. Due to the overlap of symptoms with several other primary headache syndromes, IIH is likely underdiagnosed.

69482

acrac_69482_14

Headache PCAs

Headache is present in 90% of patients with IIH and is commonly the presenting symptom. The diagnostic criteria as per the ICHD-3 includes a documentation of intracranial pressure exceeding 250 mm H2O (or 280 mm H2O in obese children). A lumbar puncture to document opening pressure remains a required diagnostic tool for the diagnosis of IIH. Physical examination findings such as papilledema is a cardinal feature of IIH. Recognition of IIH and treatment is predominantly aimed preserving vision. The role of neuroimaging is mostly to exclude secondary causes of elevated intracranial pressure and to aid in the diagnosis of IIH [23,35,36]. It can also identify venous outflow problems, which can contribute to elevated intracranial pressure in both primary and secondary intracranial hypertension. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of headache with features of intracranial hypertension. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CTV Head With IV Contrast Theories regarding the pathophysiology of IIH include venous outflow obstruction leading to increased intracranial pressure, which can compress and narrow the distal transverse sinuses. Several studies have demonstrated a finding

Headache PCAs. Headache is present in 90% of patients with IIH and is commonly the presenting symptom. The diagnostic criteria as per the ICHD-3 includes a documentation of intracranial pressure exceeding 250 mm H2O (or 280 mm H2O in obese children). A lumbar puncture to document opening pressure remains a required diagnostic tool for the diagnosis of IIH. Physical examination findings such as papilledema is a cardinal feature of IIH. Recognition of IIH and treatment is predominantly aimed preserving vision. The role of neuroimaging is mostly to exclude secondary causes of elevated intracranial pressure and to aid in the diagnosis of IIH [23,35,36]. It can also identify venous outflow problems, which can contribute to elevated intracranial pressure in both primary and secondary intracranial hypertension. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of headache with features of intracranial hypertension. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. CTV Head With IV Contrast Theories regarding the pathophysiology of IIH include venous outflow obstruction leading to increased intracranial pressure, which can compress and narrow the distal transverse sinuses. Several studies have demonstrated a finding

69482

acrac_69482_15

Headache PCAs

Headache of venous sinus stenosis or thrombosis in patients with suspected IIH and patients with chronic headaches, which reinforces the value of venous imaging for unexplained headaches, especially when there are features of intracranial hypertension [38-40]. Several studies have also demonstrated the increased utility of CTV with IV contrast when compared with time-of-flight MRI techniques [36,38]. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRI Head Without and With IV Contrast Brain MRI can be useful to detect imaging signs that are associated with primary IIH and to help exclude secondary causes of elevated intracranial pressure, including structural abnormalities such as mass, edema, or hydrocephalus [37]. Although IV contrast is not required to visualize the structural alterations associated with IIH or mass/hydrocephalus, it can be useful for characterization of an intracranial mass and for depiction of the venous sinuses. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial imaging evaluation of headache with features of intracranial hypertension. For example, brain MRI can evaluate for secondary causes of elevated intracranial pressure, including structural abnormalities such as mass, edema, or hydrocephalus. In addition, brain MRI can detect subtle findings that have been described in the literature that are associated with primary IIH.

Headache PCAs. Headache of venous sinus stenosis or thrombosis in patients with suspected IIH and patients with chronic headaches, which reinforces the value of venous imaging for unexplained headaches, especially when there are features of intracranial hypertension [38-40]. Several studies have also demonstrated the increased utility of CTV with IV contrast when compared with time-of-flight MRI techniques [36,38]. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypertension. MRI Head Without and With IV Contrast Brain MRI can be useful to detect imaging signs that are associated with primary IIH and to help exclude secondary causes of elevated intracranial pressure, including structural abnormalities such as mass, edema, or hydrocephalus [37]. Although IV contrast is not required to visualize the structural alterations associated with IIH or mass/hydrocephalus, it can be useful for characterization of an intracranial mass and for depiction of the venous sinuses. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial imaging evaluation of headache with features of intracranial hypertension. For example, brain MRI can evaluate for secondary causes of elevated intracranial pressure, including structural abnormalities such as mass, edema, or hydrocephalus. In addition, brain MRI can detect subtle findings that have been described in the literature that are associated with primary IIH.

69482

acrac_69482_16

Headache PCAs

Based on a 2011 study including patients with elevated intracranial pressure, 6 signs were more prevalent in patients with IIH: partially empty sella, posterior displacement of the pituitary stalk, flattening of the posterior globe, optic nerve head protrusion, optic nerve sheath distension, and optic nerve sheath tortuosity. Three of the above signs were shown to be highly specific for IIH: partially empty sella, flattening of the posterior globe, and optic nerve head protrusion [35,41]. A small-scale study has shown the potential utility of semiautomated volumetric evaluation of the optic nerve sheath and hypophysis to help diagnose IIH [42]. MRV Head With IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension. The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. MRV Head Without and With IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension.

Headache PCAs. Based on a 2011 study including patients with elevated intracranial pressure, 6 signs were more prevalent in patients with IIH: partially empty sella, posterior displacement of the pituitary stalk, flattening of the posterior globe, optic nerve head protrusion, optic nerve sheath distension, and optic nerve sheath tortuosity. Three of the above signs were shown to be highly specific for IIH: partially empty sella, flattening of the posterior globe, and optic nerve head protrusion [35,41]. A small-scale study has shown the potential utility of semiautomated volumetric evaluation of the optic nerve sheath and hypophysis to help diagnose IIH [42]. MRV Head With IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension. The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. MRV Head Without and With IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension.

69482

acrac_69482_17

Headache PCAs

The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Headache Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. MRV Head Without IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension. The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of headache with features of intracranial hypotension. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension; although some findings of SIH can be detected on noncontrast head CT, contrast-enhanced brain MRI is needed to evaluate for pachymeningeal enhancement.

Headache PCAs. The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Headache Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. MRV Head Without IV Contrast Venous outflow obstruction either by an intraluminal thrombus or an extrinsic stenosis has been shown to be associated with elevated intracranial pressure and IIH; therefore, venous imaging such as brain MRV can be useful in the imaging evaluation of headache with features of intracranial hypertension. The decision to use noncontrast (eg, time-of-flight or phase-contrast) versus contrast techniques may depend on the preferences of different institutions. The use of IV contrast helps clearly delineate the venous sinus lumen and avoids some of the flow- related artifacts encountered in noncontrast MRV techniques, which can be more prone to misinterpretation [36,38]. Therefore, noncontrast brain MRV should be interpreted with attention to possible artifacts related to slow or turbulent flow and in conjunction with brain MRI, if previously performed. Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of headache with features of intracranial hypotension. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension; although some findings of SIH can be detected on noncontrast head CT, contrast-enhanced brain MRI is needed to evaluate for pachymeningeal enhancement.

69482

acrac_69482_18

Headache PCAs

CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. Headache MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRI Head Without and With IV Contrast MRI head without and with IV contrast is useful in the initial imaging evaluation of headache with features of intracranial hypotension. The most common brain MRI findings include pachymeningeal enhancement (reported in 83% of patients), subdural fluid collections, brain/brainstem sagging, downward displacement of cerebellar tonsils, distension of venous structures/sinuses, and enlargement of the pituitary gland. Orbital findings include a collapsed optic nerve sheath and a straightened optic nerve angle.

Headache PCAs. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CT Head Without IV Contrast There is no relevant literature to support the use of CT head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. CTV Head With IV Contrast There is no relevant literature to support the use of CTV head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. Headache MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRI Head Without and With IV Contrast MRI head without and with IV contrast is useful in the initial imaging evaluation of headache with features of intracranial hypotension. The most common brain MRI findings include pachymeningeal enhancement (reported in 83% of patients), subdural fluid collections, brain/brainstem sagging, downward displacement of cerebellar tonsils, distension of venous structures/sinuses, and enlargement of the pituitary gland. Orbital findings include a collapsed optic nerve sheath and a straightened optic nerve angle.

69482

acrac_69482_19

Headache PCAs

It should be noted that the venous sinus, pituitary gland, and optic nerve sheath findings are opposite of what is seen in IIH or intracranial hypertension, as expected. It should also be noted that these need to be interpreted in the appropriate clinical context of orthostatic headaches, because there are other diseases with overlapping imaging findings: downward displacement of cerebellar tonsils in Chiari type 1 malformation, subdural fluid collections due to trauma, and diffuse dural thickening due to inflammatory conditions such as immunoglobulin G4-related disease and neurosarcoidosis [43-45]. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension; although some findings of SIH can be detected on noncontrast brain MRI, contrast-enhanced brain MRI is needed to evaluate for pachymeningeal enhancement. MRI Thoracic Spine With IV Contrast Although the primary purpose of spine imaging is to look for an extradural fluid collection that would be consistent with a dural tear, which does not require contrast, there may be scenarios where postcontrast imaging of the spine is reasonable, for example, when contrast is being administered for concurrent brain MRI or when contrast is needed to differentiate enhancing epidural venous distension from nonenhancing epidural fluid collection. MRI Thoracic Spine Without and With IV Contrast Although the primary purpose of spine imaging is to look for an extradural fluid collection that would be consistent with a dural tear, which does not require contrast, there may be scenarios where postcontrast imaging of the spine is reasonable, for example, when contrast is being administered for concurrent brain MRI or when contrast is needed to differentiate enhancing epidural venous distension from nonenhancing epidural fluid collection.

Headache PCAs. It should be noted that the venous sinus, pituitary gland, and optic nerve sheath findings are opposite of what is seen in IIH or intracranial hypertension, as expected. It should also be noted that these need to be interpreted in the appropriate clinical context of orthostatic headaches, because there are other diseases with overlapping imaging findings: downward displacement of cerebellar tonsils in Chiari type 1 malformation, subdural fluid collections due to trauma, and diffuse dural thickening due to inflammatory conditions such as immunoglobulin G4-related disease and neurosarcoidosis [43-45]. MRI Head Without IV Contrast There is no relevant literature to support the use of MRI head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension; although some findings of SIH can be detected on noncontrast brain MRI, contrast-enhanced brain MRI is needed to evaluate for pachymeningeal enhancement. MRI Thoracic Spine With IV Contrast Although the primary purpose of spine imaging is to look for an extradural fluid collection that would be consistent with a dural tear, which does not require contrast, there may be scenarios where postcontrast imaging of the spine is reasonable, for example, when contrast is being administered for concurrent brain MRI or when contrast is needed to differentiate enhancing epidural venous distension from nonenhancing epidural fluid collection. MRI Thoracic Spine Without and With IV Contrast Although the primary purpose of spine imaging is to look for an extradural fluid collection that would be consistent with a dural tear, which does not require contrast, there may be scenarios where postcontrast imaging of the spine is reasonable, for example, when contrast is being administered for concurrent brain MRI or when contrast is needed to differentiate enhancing epidural venous distension from nonenhancing epidural fluid collection.

69482

acrac_69482_20

Headache PCAs

MRI Thoracic Spine Without IV Contrast MRI spine without IV contrast is useful in the initial imaging evaluation of headache with features of intracranial hypotension. The primary purpose is to look for an extradural fluid collection in the spinal canal, usually at the level of the thoracic spine, that would be consistent with a dural tear (type 1 or type 2 CSF leak). Identification of such a fluid collection can help to guide further management or to confirm a diagnosis of SIH in rare cases in which brain MRI is normal. Other spine MRI findings that have been reported in SIH include dural enhancement, distension of epidural veins, and abnormal visualization of nerve root sleeves. Although some patients with a spinal CSF leak will respond to horizontal bedrest and/or nontargeted epidural blood patches in the lumbar spine, others will have refractory symptoms and require spinal CSF leak localization for targeted therapy. Heavily T2-weighted MR myelography without the use of intrathecal contrast is an emerging noninvasive technique for detecting CSF leaks without the need for a lumbar puncture and radiation exposure. This technique can also be used to guide targeted epidural blood patches. A study conducted in Korea replaced CT myelography with heavily T2-weighted MR myelography (performed on a 3T MRI) for 26 patients who presented with headache attributed to Headache low CSF pressure. This study demonstrated CSF leak detection in 80.8% of the patients. The findings of heavily T2-weighted MR myelography was used to plan epidural blood patches placement; complete relief of symptoms was achieved in 82.4% of patients in whom a CSF leak was seen using heavily T2-weighted MR myelography [46]. Minimally invasive methods for spinal CSF leak localization include conventional CT myelography, dynamic CT myelography, digital subtraction myelography, and MR myelography with intrathecal injection of contrast.

Headache PCAs. MRI Thoracic Spine Without IV Contrast MRI spine without IV contrast is useful in the initial imaging evaluation of headache with features of intracranial hypotension. The primary purpose is to look for an extradural fluid collection in the spinal canal, usually at the level of the thoracic spine, that would be consistent with a dural tear (type 1 or type 2 CSF leak). Identification of such a fluid collection can help to guide further management or to confirm a diagnosis of SIH in rare cases in which brain MRI is normal. Other spine MRI findings that have been reported in SIH include dural enhancement, distension of epidural veins, and abnormal visualization of nerve root sleeves. Although some patients with a spinal CSF leak will respond to horizontal bedrest and/or nontargeted epidural blood patches in the lumbar spine, others will have refractory symptoms and require spinal CSF leak localization for targeted therapy. Heavily T2-weighted MR myelography without the use of intrathecal contrast is an emerging noninvasive technique for detecting CSF leaks without the need for a lumbar puncture and radiation exposure. This technique can also be used to guide targeted epidural blood patches. A study conducted in Korea replaced CT myelography with heavily T2-weighted MR myelography (performed on a 3T MRI) for 26 patients who presented with headache attributed to Headache low CSF pressure. This study demonstrated CSF leak detection in 80.8% of the patients. The findings of heavily T2-weighted MR myelography was used to plan epidural blood patches placement; complete relief of symptoms was achieved in 82.4% of patients in whom a CSF leak was seen using heavily T2-weighted MR myelography [46]. Minimally invasive methods for spinal CSF leak localization include conventional CT myelography, dynamic CT myelography, digital subtraction myelography, and MR myelography with intrathecal injection of contrast.

69482

acrac_69482_21

Headache PCAs

These techniques are, therefore, useful in the follow-up imaging evaluation of headache with features of intracranial hypotension, when refractory to nontargeted therapy. The choice between spinal CSF leak localization techniques may depend on the suspected CSF leak type (dural tear versus distal nerve root sleeve) and also on the preferences of different institutions. Although radioisotope cisternography can be used in some scenarios to help confirm the presence of a spinal CSF leak, it has insufficient spatial resolution for precise leak localization. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. Variant 6: Headache with new onset or pattern during pregnancy or peripartum period. Initial imaging. Thirty-five percent of pregnant women and 40% of postpartum women experience headache. Although migraine headaches are common, evidence shows that during the second trimester, migraine symptoms typically improve. More than a third of pregnant women presenting to the hospital can have a secondary headache [47-49]. Total blood volume increase (by 40% at term) and rising progesterone levels in the third trimester can contribute to increased venous compliance. These are factors that can explain some of the neurological complications in pregnancy [49]. A study at an urban medical center conducted over a 5-year period examining 140 pregnant women presenting with acute headache demonstrated an incidence of secondary headaches in 35%.

Headache PCAs. These techniques are, therefore, useful in the follow-up imaging evaluation of headache with features of intracranial hypotension, when refractory to nontargeted therapy. The choice between spinal CSF leak localization techniques may depend on the suspected CSF leak type (dural tear versus distal nerve root sleeve) and also on the preferences of different institutions. Although radioisotope cisternography can be used in some scenarios to help confirm the presence of a spinal CSF leak, it has insufficient spatial resolution for precise leak localization. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. MRV Head Without IV Contrast There is no relevant literature to support the use of MRV head without IV contrast in the initial imaging evaluation of headache with features of intracranial hypotension. Variant 6: Headache with new onset or pattern during pregnancy or peripartum period. Initial imaging. Thirty-five percent of pregnant women and 40% of postpartum women experience headache. Although migraine headaches are common, evidence shows that during the second trimester, migraine symptoms typically improve. More than a third of pregnant women presenting to the hospital can have a secondary headache [47-49]. Total blood volume increase (by 40% at term) and rising progesterone levels in the third trimester can contribute to increased venous compliance. These are factors that can explain some of the neurological complications in pregnancy [49]. A study at an urban medical center conducted over a 5-year period examining 140 pregnant women presenting with acute headache demonstrated an incidence of secondary headaches in 35%.

69482

acrac_69482_22

Headache PCAs

Within this group, hypertensive disorder of pregnancy was most common, predominated by preeclampsia [47]. Various secondary headaches are more likely to occur during pregnancy, which may be related to hypercoagulability, hormonal factors, and anesthesia for labor. Pregnancy-induced hypercoagulability is an adaptive physiologic mechanism that reduces the risk of hemorrhage but increases the risk of thromboembolism; this risk extends into the postpartum period, which is defined as the first 6 weeks following delivery. Conditions related to the hypercoagulability and endothelial dysfunction include cerebral venous sinus thrombosis and RCVS. A subset of pregnancy-related RCVS is postpartum angiopathy, which is an important cause of headache in these patients and which may be underdiagnosed. Intracranial hypotension from iatrogenic CSF leak is another important consideration in postpartum patients, which may follow spinal anesthesia or inadvertent dural puncture during epidural anesthesia (also refer to Variant 5) [12,49]. The incidence of primary malignant tumors in pregnant women is slightly lower than in nonpregnant women; however, studies have shown that both tumor volume and growth increase during pregnancy, especially with respect to gliomas. Lesions such as meningiomas express progesterone receptors and are known to regress after pregnancy. These gestational tumoral changes also correlated with clinical worsening and increased frequency of seizure that may precipitate obstetrical emergencies [50]. Breast cancer and choriocarcinoma are 2 of the most common types of cancers that can metastasize to the brain in pregnancy [49]. Pituitary disorders are also a cause of symptoms during pregnancy. The adenohypophysis increases in volume by 30% in pregnancy. Prolactinomas are the most common pituitary tumors occurring during pregnancy, and a small percentage of microadenomas show signs of tumor enlargement.

Headache PCAs. Within this group, hypertensive disorder of pregnancy was most common, predominated by preeclampsia [47]. Various secondary headaches are more likely to occur during pregnancy, which may be related to hypercoagulability, hormonal factors, and anesthesia for labor. Pregnancy-induced hypercoagulability is an adaptive physiologic mechanism that reduces the risk of hemorrhage but increases the risk of thromboembolism; this risk extends into the postpartum period, which is defined as the first 6 weeks following delivery. Conditions related to the hypercoagulability and endothelial dysfunction include cerebral venous sinus thrombosis and RCVS. A subset of pregnancy-related RCVS is postpartum angiopathy, which is an important cause of headache in these patients and which may be underdiagnosed. Intracranial hypotension from iatrogenic CSF leak is another important consideration in postpartum patients, which may follow spinal anesthesia or inadvertent dural puncture during epidural anesthesia (also refer to Variant 5) [12,49]. The incidence of primary malignant tumors in pregnant women is slightly lower than in nonpregnant women; however, studies have shown that both tumor volume and growth increase during pregnancy, especially with respect to gliomas. Lesions such as meningiomas express progesterone receptors and are known to regress after pregnancy. These gestational tumoral changes also correlated with clinical worsening and increased frequency of seizure that may precipitate obstetrical emergencies [50]. Breast cancer and choriocarcinoma are 2 of the most common types of cancers that can metastasize to the brain in pregnancy [49]. Pituitary disorders are also a cause of symptoms during pregnancy. The adenohypophysis increases in volume by 30% in pregnancy. Prolactinomas are the most common pituitary tumors occurring during pregnancy, and a small percentage of microadenomas show signs of tumor enlargement.

69482

acrac_69482_23

Headache PCAs

Lymphocytic hypophysitis is a rare inflammatory autoimmune disorder of the pituitary gland/stalk that can occur in the postpartum period or in the third trimester. Typically, these lesions can present with visual symptoms due to impingement of the optic chiasm in addition to symptoms of headache and hypopituitarism. Pituitary apoplexy can present similarly in the setting of postpartum hemorrhage (Sheehan syndrome) [49]. Headache Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of new headache during pregnancy or peripartum period. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period, unless there is TCH and suspicion for aneurysmal SAH or RCVS (also refer to Variant 1). Overall, the risk of intracerebral hemorrhage in pregnant women is rare; however, the risk of SAH rises dramatically in the postpartum period. As such, these patients may present with a classic TCH, and etiologies for SAH should be considered. Other conditions such as arterial dissections are also seen in pregnancy and are usually associated with preeclampsia [51]. After an initial head CT, a concurrent or follow-up CTA is useful in suspected cases of intracranial aneurysm (ruptured or unruptured), arterial dissection, and RCVS, which can occur within the first month of pregnancy and most often within 10 days [10-12,18,49].

Headache PCAs. Lymphocytic hypophysitis is a rare inflammatory autoimmune disorder of the pituitary gland/stalk that can occur in the postpartum period or in the third trimester. Typically, these lesions can present with visual symptoms due to impingement of the optic chiasm in addition to symptoms of headache and hypopituitarism. Pituitary apoplexy can present similarly in the setting of postpartum hemorrhage (Sheehan syndrome) [49]. Headache Arteriography Cervicocerebral There is no relevant literature to support the use of cervicocerebral arteriography in the initial imaging evaluation of new headache during pregnancy or peripartum period. CT Head With IV Contrast There is no relevant literature to support the use of CT head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. CTA Head With IV Contrast There is no relevant literature to support the use of CTA head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period, unless there is TCH and suspicion for aneurysmal SAH or RCVS (also refer to Variant 1). Overall, the risk of intracerebral hemorrhage in pregnant women is rare; however, the risk of SAH rises dramatically in the postpartum period. As such, these patients may present with a classic TCH, and etiologies for SAH should be considered. Other conditions such as arterial dissections are also seen in pregnancy and are usually associated with preeclampsia [51]. After an initial head CT, a concurrent or follow-up CTA is useful in suspected cases of intracranial aneurysm (ruptured or unruptured), arterial dissection, and RCVS, which can occur within the first month of pregnancy and most often within 10 days [10-12,18,49].

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Headache PCAs

CTV Head With IV Contrast CTV head with IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, as this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. In pregnant patients requiring contrast-enhanced evaluation of the dural venous sinuses, CTV is the modality of choice because iodinated contrast agents are generally considered safer than gadolinium-based contrast agents (GBCA) with regard to potential effects on the fetus. After an initial head CT, a concurrent or follow-up CTV is useful in suspected cases of venous thrombosis. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. In some scenarios, brain MRA may be useful following or in conjunction with brain MRI when evaluating for cerebrovascular etiologies of headache such as RCVS [12,52]. Headache MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.

Headache PCAs. CTV Head With IV Contrast CTV head with IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, as this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. In pregnant patients requiring contrast-enhanced evaluation of the dural venous sinuses, CTV is the modality of choice because iodinated contrast agents are generally considered safer than gadolinium-based contrast agents (GBCA) with regard to potential effects on the fetus. After an initial head CT, a concurrent or follow-up CTV is useful in suspected cases of venous thrombosis. MRA Head With IV Contrast There is no relevant literature to support the use of MRA head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without and With IV Contrast There is no relevant literature to support the use of MRA head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRA Head Without IV Contrast There is no relevant literature to support the use of MRA head without IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period. In some scenarios, brain MRA may be useful following or in conjunction with brain MRI when evaluating for cerebrovascular etiologies of headache such as RCVS [12,52]. Headache MRI Head With IV Contrast There is no relevant literature to support the use of MRI head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.

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Headache PCAs

MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period. There are multiple etiologies that can cause secondary headaches in pregnant women. For TCH, there is the possibility of arterial pathologies such as aneurysmal SAH or RCVS, especially in the postpartum period (also refer to Variant 1). Structural lesions include intracranial neoplasms and lesions originating from the pituitary gland. Another condition to consider is intracranial hypertension, especially in an obese female (also refer to variant 4). Preeclampsia and eclampsia are diseases of pregnancy that can present with headache and with findings of PRES on neuroimaging [47,49-51]. Brain MRI is the study of choice to evaluate for vasogenic edema due to endothelial dysfunction in PRES. It is best seen on FLAIR and T2-weighted imaging, which is more sensitive for abnormalities in the posterior fossa than head CT, which is abnormal in 45% of patients with PRES. In the setting of headache with new onset seizures, MRI can potentially detect the causative mass/lesion or PRES to support a diagnosis of eclampsia. [49,50]. Lesions originating from the pituitary gland are also readily detectable on MRI [30,49]. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.

Headache PCAs. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRI Head Without IV Contrast MRI head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period. There are multiple etiologies that can cause secondary headaches in pregnant women. For TCH, there is the possibility of arterial pathologies such as aneurysmal SAH or RCVS, especially in the postpartum period (also refer to Variant 1). Structural lesions include intracranial neoplasms and lesions originating from the pituitary gland. Another condition to consider is intracranial hypertension, especially in an obese female (also refer to variant 4). Preeclampsia and eclampsia are diseases of pregnancy that can present with headache and with findings of PRES on neuroimaging [47,49-51]. Brain MRI is the study of choice to evaluate for vasogenic edema due to endothelial dysfunction in PRES. It is best seen on FLAIR and T2-weighted imaging, which is more sensitive for abnormalities in the posterior fossa than head CT, which is abnormal in 45% of patients with PRES. In the setting of headache with new onset seizures, MRI can potentially detect the causative mass/lesion or PRES to support a diagnosis of eclampsia. [49,50]. Lesions originating from the pituitary gland are also readily detectable on MRI [30,49]. MRV Head With IV Contrast There is no relevant literature to support the use of MRV head with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy.

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Headache PCAs

MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRV Head Without IV Contrast MRV head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, because this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. After an initial brain MRI, a concurrent or follow-up MRV is useful in suspected cases of venous thrombosis. Because the recommendation is to avoid administering IV GBCA during pregnancy, this is typically performed using a noncontrast technique such as time-of-flight or phase-contrast imaging. Over the course of the last 2 decades, several studies have demonstrated a higher incidence of neuropathology for selected patients with certain red and orange flags. For example, a British literature review demonstrated that in the primary care setting, the risk of a brain tumor with a headache presentation is 0.09%; however, when the headache was associated with abnormal findings on neurologic examination, with aggravation by exertion, with vomiting, or Headache Posttraumatic onset headaches are defined as those that develop within a 7-day interval of trauma by the ICHD-3; this subset of headaches is defined as chronic or persistent if they persist beyond 3 months [23,55]. Headache One study examining 3,630 patient records noted clinically significant abnormal noncontrast CT scans in 7 patients who had a normal neurologic examination. In this study, these 7 patients described their headaches as severe and nonremitting. The study concludes that noncontrast head CT may be useful for patients suffering from severe and unremitting headaches [62].

Headache PCAs. MRV Head Without and With IV Contrast There is no relevant literature to support the use of MRV head without and with IV contrast in the initial imaging evaluation of new headache during pregnancy or peripartum period; the recommendation is to avoid administering IV GBCA during pregnancy. MRV Head Without IV Contrast MRV head without IV contrast can be useful in the initial imaging evaluation of new headache during pregnancy or peripartum period, because this patient demographic is at a higher risk for thromboembolic complications such as CVT, especially in the postpartum period [12,49]. After an initial brain MRI, a concurrent or follow-up MRV is useful in suspected cases of venous thrombosis. Because the recommendation is to avoid administering IV GBCA during pregnancy, this is typically performed using a noncontrast technique such as time-of-flight or phase-contrast imaging. Over the course of the last 2 decades, several studies have demonstrated a higher incidence of neuropathology for selected patients with certain red and orange flags. For example, a British literature review demonstrated that in the primary care setting, the risk of a brain tumor with a headache presentation is 0.09%; however, when the headache was associated with abnormal findings on neurologic examination, with aggravation by exertion, with vomiting, or Headache Posttraumatic onset headaches are defined as those that develop within a 7-day interval of trauma by the ICHD-3; this subset of headaches is defined as chronic or persistent if they persist beyond 3 months [23,55]. Headache One study examining 3,630 patient records noted clinically significant abnormal noncontrast CT scans in 7 patients who had a normal neurologic examination. In this study, these 7 patients described their headaches as severe and nonremitting. The study concludes that noncontrast head CT may be useful for patients suffering from severe and unremitting headaches [62].

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acrac_69503_0

Acute Pelvic Pain in the Reproductive Age Group

Introduction/Background Premenopausal patients with acute pelvic pain often pose a diagnostic dilemma. They may exhibit additional nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. The differential considerations encompass gynecological and obstetrical causes (eg, hemorrhagic ovarian cysts, pelvic inflammatory disease [PID], ovarian torsion, ectopic pregnancy, spontaneous abortion, or labor and placental abruption), as well as nongynecological etiologies (eg, appendicitis, inflammatory bowel disease, infectious enteritis, diverticulitis, urinary tract calculi, pyelonephritis, and pelvic thrombophlebitis). The choice of imaging modality is determined by the most likely clinically suspected differential diagnosis, because each modality differs in the ability to depict disease in the various pelvic organs. Thus, a thorough clinical evaluation of the patient is required to determine the index of suspicion among the various etiologies. Diagnostic considerations should be based upon the correlation of history, physical examination, and laboratory testing before a radiologic examination is chosen. Details on risk to the fetus, as well as guidelines on screening for pregnancy, minimizing radiation exposure, and risk assessment, can be found throughout this document. Special Imaging Considerations Details on risk to the fetus, guideline on screening for pregnancy, minimizing radiation exposure, and risk assessment can be found in the ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [1]. Use of contrast in MRI during pregnancy should be done with caution, because the gadolinium-chelate molecules are excreted in the amniotic fluid and may remain there for an indeterminate amount of time before finally being reabsorbed and eliminated [2].

Acute Pelvic Pain in the Reproductive Age Group. Introduction/Background Premenopausal patients with acute pelvic pain often pose a diagnostic dilemma. They may exhibit additional nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. The differential considerations encompass gynecological and obstetrical causes (eg, hemorrhagic ovarian cysts, pelvic inflammatory disease [PID], ovarian torsion, ectopic pregnancy, spontaneous abortion, or labor and placental abruption), as well as nongynecological etiologies (eg, appendicitis, inflammatory bowel disease, infectious enteritis, diverticulitis, urinary tract calculi, pyelonephritis, and pelvic thrombophlebitis). The choice of imaging modality is determined by the most likely clinically suspected differential diagnosis, because each modality differs in the ability to depict disease in the various pelvic organs. Thus, a thorough clinical evaluation of the patient is required to determine the index of suspicion among the various etiologies. Diagnostic considerations should be based upon the correlation of history, physical examination, and laboratory testing before a radiologic examination is chosen. Details on risk to the fetus, as well as guidelines on screening for pregnancy, minimizing radiation exposure, and risk assessment, can be found throughout this document. Special Imaging Considerations Details on risk to the fetus, guideline on screening for pregnancy, minimizing radiation exposure, and risk assessment can be found in the ACR-SPR Practice Parameter for Imaging Pregnant or Potentially Pregnant Adolescents and Women with Ionizing Radiation [1]. Use of contrast in MRI during pregnancy should be done with caution, because the gadolinium-chelate molecules are excreted in the amniotic fluid and may remain there for an indeterminate amount of time before finally being reabsorbed and eliminated [2].

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Acute Pelvic Pain in the Reproductive Age Group

Gadolinium is considered a pregnancy category C drug (it should be administered only if the potential benefit outweighs the risk) because animal studies have revealed adverse effects. Among 26 patients who had exposure to gadopentetate-dimeglumine in the periconceptional and first trimester period, only one congenital birth anomaly was found (hemangiomas) [3]. However, no well-controlled studies of the teratogenic effects of these media in The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Acute Pelvic Pain in the Reproductive Age Group pregnant patients have been performed. Thus, if the information requested from the MRI study with intravenous (IV) contrast cannot be acquired using other modalities and is needed to potentially affect the care of the patient or fetus during the pregnancy, and the ordering physician believes that it is not prudent to wait until the patient is no longer pregnant, IV contrast may be administered and the rationale diligently documented. It is recommended that informed consent be obtained from the patient after discussion with the referring physician [4]. Acute Pelvic Pain in the Reproductive Age Group Generally, MRI of the pelvis may provide sufficient anatomic coverage without including the entire abdomen as with MRI of the abdomen and pelvis and, thus, may be used in selected cases as a second-line imaging modality. Cesarean scar pregnancy was accurately diagnosed in 95.5% of cases using contrast-enhanced MRI compared with 88.6% using US in a retrospective analysis of 44 patients with cesarean section scar pregnancy.

Acute Pelvic Pain in the Reproductive Age Group. Gadolinium is considered a pregnancy category C drug (it should be administered only if the potential benefit outweighs the risk) because animal studies have revealed adverse effects. Among 26 patients who had exposure to gadopentetate-dimeglumine in the periconceptional and first trimester period, only one congenital birth anomaly was found (hemangiomas) [3]. However, no well-controlled studies of the teratogenic effects of these media in The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Acute Pelvic Pain in the Reproductive Age Group pregnant patients have been performed. Thus, if the information requested from the MRI study with intravenous (IV) contrast cannot be acquired using other modalities and is needed to potentially affect the care of the patient or fetus during the pregnancy, and the ordering physician believes that it is not prudent to wait until the patient is no longer pregnant, IV contrast may be administered and the rationale diligently documented. It is recommended that informed consent be obtained from the patient after discussion with the referring physician [4]. Acute Pelvic Pain in the Reproductive Age Group Generally, MRI of the pelvis may provide sufficient anatomic coverage without including the entire abdomen as with MRI of the abdomen and pelvis and, thus, may be used in selected cases as a second-line imaging modality. Cesarean scar pregnancy was accurately diagnosed in 95.5% of cases using contrast-enhanced MRI compared with 88.6% using US in a retrospective analysis of 44 patients with cesarean section scar pregnancy.

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acrac_69503_2

Acute Pelvic Pain in the Reproductive Age Group

This suggests that contrast-enhanced MRI could be used as a reliable adjunct for diagnosing cesarean scar pregnancy in select cases or if US is inconclusive or nondiagnostic. The typical findings of a gestational sac embedded in the anterior lower part of the uterus in the sagittal T2-weighted views were identified in all the patients. However, MRI examinations were performed approximately 5 days after the US examinations, which may have resulted in some bias, and same- day studies might have yielded similar sensitivity between both modalities [6]. Please refer to the Special Imaging Considerations section above for a discussion about the use of gadolinium-based contrast in the setting of pregnancy. In the early 1990s, Doppler imaging was suggested as a tool allowing for increased detection rate of ectopic pregnancy, increasing sensitivity from 71% to 87% [11]; however, a recent study evaluating the correlation between adnexal sonographic findings and tubal rupture found no statistically significant correlation. Nonspecific adnexal Acute Pelvic Pain in the Reproductive Age Group findings allows earlier detection of ectopic pregnancy than previously reported findings of detection of a yolk sac or embryonic heartbeat [12]. US Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach could serve as an alternative if a transvaginal approach is not feasible. TVUS and transabdominal US (TAUS) of the pelvis are the most useful imaging modalities for initial assessment when an obstetrical or gynecological etiology is suspected [13]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. TVUS is the most useful method to evaluate the endometrium, early pregnancy, and adnexa [14].

Acute Pelvic Pain in the Reproductive Age Group. This suggests that contrast-enhanced MRI could be used as a reliable adjunct for diagnosing cesarean scar pregnancy in select cases or if US is inconclusive or nondiagnostic. The typical findings of a gestational sac embedded in the anterior lower part of the uterus in the sagittal T2-weighted views were identified in all the patients. However, MRI examinations were performed approximately 5 days after the US examinations, which may have resulted in some bias, and same- day studies might have yielded similar sensitivity between both modalities [6]. Please refer to the Special Imaging Considerations section above for a discussion about the use of gadolinium-based contrast in the setting of pregnancy. In the early 1990s, Doppler imaging was suggested as a tool allowing for increased detection rate of ectopic pregnancy, increasing sensitivity from 71% to 87% [11]; however, a recent study evaluating the correlation between adnexal sonographic findings and tubal rupture found no statistically significant correlation. Nonspecific adnexal Acute Pelvic Pain in the Reproductive Age Group findings allows earlier detection of ectopic pregnancy than previously reported findings of detection of a yolk sac or embryonic heartbeat [12]. US Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach could serve as an alternative if a transvaginal approach is not feasible. TVUS and transabdominal US (TAUS) of the pelvis are the most useful imaging modalities for initial assessment when an obstetrical or gynecological etiology is suspected [13]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. TVUS is the most useful method to evaluate the endometrium, early pregnancy, and adnexa [14].

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Acute Pelvic Pain in the Reproductive Age Group

TVUS is currently considered the single best diagnostic modality to assess for ectopic pregnancy [15]. In a retrospective study of 1,880 patients presenting to the emergency department with first trimester pain or vaginal bleeding, an overall accuracy of TVUS diagnosis was 78%, with a specificity above 90% but a low sensitivity of 35%. The sensitivity for ectopic and intrauterine pregnancy diagnosis is even lower in the absence of a yolk sac, 13% for ectopic pregnancy and 4% for intrauterine pregnancy. However, specificity is preserved in the absence of the yolk sac and remains above 90% [18]. A meta-analysis of 14 studies with 12,101 patients with ectopic pregnancy showed a positive likelihood ratio of 111 for the finding of adnexal mass without an intrauterine pregnancy on TVUS. This makes TVUS the single best diagnostic modality for evaluating patients with suspected ectopic pregnancy. A lack of adnexal abnormalities on TVUS decreases the likelihood of ectopic pregnancy with a negative likelihood ratio of 0.12 [15]. CT findings of tubo-ovarian abscess (TOA) include a thick-walled fluid density in adnexal location, septations within the mass, indistinct borders between the uterus and adjacent bowel loops, and gas bubbles within the mass. Other findings include thickening and anterior displacement of the round ligament, which suggest adnexal origin rather than gastrointestinal tract origin. Findings of a tubular cystic lesion with multiple satellite lesions were pathologically proven to be pyosalpinx in 10 of 14 cases [23]. The presence of a right ovarian vein entering a right pelvic abscess had a 100% specificity and 94% sensitivity to TOA and may help differentiate from peri-appendiceal abscess [24]. In the setting of endometriosis, CT evaluation may demonstrate secondary signs of architectural distortion, thickening of bowel serosa, or even bowel obstruction, although the imaging findings may not be specific to deep pelvic endometriosis.

Acute Pelvic Pain in the Reproductive Age Group. TVUS is currently considered the single best diagnostic modality to assess for ectopic pregnancy [15]. In a retrospective study of 1,880 patients presenting to the emergency department with first trimester pain or vaginal bleeding, an overall accuracy of TVUS diagnosis was 78%, with a specificity above 90% but a low sensitivity of 35%. The sensitivity for ectopic and intrauterine pregnancy diagnosis is even lower in the absence of a yolk sac, 13% for ectopic pregnancy and 4% for intrauterine pregnancy. However, specificity is preserved in the absence of the yolk sac and remains above 90% [18]. A meta-analysis of 14 studies with 12,101 patients with ectopic pregnancy showed a positive likelihood ratio of 111 for the finding of adnexal mass without an intrauterine pregnancy on TVUS. This makes TVUS the single best diagnostic modality for evaluating patients with suspected ectopic pregnancy. A lack of adnexal abnormalities on TVUS decreases the likelihood of ectopic pregnancy with a negative likelihood ratio of 0.12 [15]. CT findings of tubo-ovarian abscess (TOA) include a thick-walled fluid density in adnexal location, septations within the mass, indistinct borders between the uterus and adjacent bowel loops, and gas bubbles within the mass. Other findings include thickening and anterior displacement of the round ligament, which suggest adnexal origin rather than gastrointestinal tract origin. Findings of a tubular cystic lesion with multiple satellite lesions were pathologically proven to be pyosalpinx in 10 of 14 cases [23]. The presence of a right ovarian vein entering a right pelvic abscess had a 100% specificity and 94% sensitivity to TOA and may help differentiate from peri-appendiceal abscess [24]. In the setting of endometriosis, CT evaluation may demonstrate secondary signs of architectural distortion, thickening of bowel serosa, or even bowel obstruction, although the imaging findings may not be specific to deep pelvic endometriosis.

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Acute Pelvic Pain in the Reproductive Age Group

Findings of irregular peripherally enhancing adnexal cyst usually accompanied by hemorrhagic pelvic free fluid might also indicate a ruptured hemorrhagic cyst. Acute Pelvic Pain in the Reproductive Age Group MRI Pelvis Without and With IV Contrast There is no relevant literature to support the use of pelvic MRI without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of ovarian torsion, PID, TOA, and other gynecological causes of acute pelvic pain in patients of reproductive age such as fibroid torsion or necrosis or in patients that are unable to tolerate TVUS. For MRI evaluation of adnexal torsion, a meta-analysis including 18 studies (1,654 patients, 665 cases) reported a pooled sensitivity of 81% and specificity of 91% [22]. An enlarged ovary with or without an underlying mass and a twisted pedicle suggest adnexal torsion (with multiplanar MRI acquisitions potentially necessary for better detection of the twisted pedicle). Other findings may include subacute ovarian hematoma (better assessed with T1- weighted sequences with fat saturation), abnormal or absent ovarian enhancement, ascites, deviation of the uterus to the side of the twist, engorged vessels on the twisted side, and fallopian tube thickening [21]. A prospective cohort study with 187 patients evaluated with MRI for PID showed a sensitivity, specificity, PPV, negative predicative value (NPV), and accuracy with conventional MRI findings (T1-weighted, T2-weighted with fat saturation, postcontrast sequences) of 90.7%, 93.3%, 98.3%, 70.0%, and 91.2%, respectively. Adding DWI yielded a sensitivity, specificity, PPV, NPV, and accuracy of 98.4%, 93.3%, 98.4%, 93.3%, and 97.5%, respectively, with overall increased accuracy, sensitivity, and NPV [25].

Acute Pelvic Pain in the Reproductive Age Group. Findings of irregular peripherally enhancing adnexal cyst usually accompanied by hemorrhagic pelvic free fluid might also indicate a ruptured hemorrhagic cyst. Acute Pelvic Pain in the Reproductive Age Group MRI Pelvis Without and With IV Contrast There is no relevant literature to support the use of pelvic MRI without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of ovarian torsion, PID, TOA, and other gynecological causes of acute pelvic pain in patients of reproductive age such as fibroid torsion or necrosis or in patients that are unable to tolerate TVUS. For MRI evaluation of adnexal torsion, a meta-analysis including 18 studies (1,654 patients, 665 cases) reported a pooled sensitivity of 81% and specificity of 91% [22]. An enlarged ovary with or without an underlying mass and a twisted pedicle suggest adnexal torsion (with multiplanar MRI acquisitions potentially necessary for better detection of the twisted pedicle). Other findings may include subacute ovarian hematoma (better assessed with T1- weighted sequences with fat saturation), abnormal or absent ovarian enhancement, ascites, deviation of the uterus to the side of the twist, engorged vessels on the twisted side, and fallopian tube thickening [21]. A prospective cohort study with 187 patients evaluated with MRI for PID showed a sensitivity, specificity, PPV, negative predicative value (NPV), and accuracy with conventional MRI findings (T1-weighted, T2-weighted with fat saturation, postcontrast sequences) of 90.7%, 93.3%, 98.3%, 70.0%, and 91.2%, respectively. Adding DWI yielded a sensitivity, specificity, PPV, NPV, and accuracy of 98.4%, 93.3%, 98.4%, 93.3%, and 97.5%, respectively, with overall increased accuracy, sensitivity, and NPV [25].

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Acute Pelvic Pain in the Reproductive Age Group

MRI with DWI and contrast-enhanced sequences showed a sensitivity of 83.3% for ovarian torsion, 100% for endometriotic cysts, 100% for hemorrhagic cysts, 83.3% for TOA, and 87.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of MRI in these pathological entities was 94.6% [26]. A TOA is characterized by an ill-defined adnexal mass with thick regular or irregular enhanced walls containing fluid. The signal intensity was variable from low signal intensity on T1-weighted images to intermediate or high signal intensity on T2-weighted images. The solid component (if present) may include thickened septa or wall, papillary projection, and various degrees of solid portions, which enhance after contrast injection. The sensitivity, specificity, PPV, NPV, and accuracy of MRI findings for predicting TOA were 47.1%, 91.4%, 84.2%, 64%, and 69.6%, respectively, in the absence of DWI and apparent diffusion coefficient (ADC) values [27]. Deep pelvic endometriosis may be identified as T2 hypointense fibrosis, most commonly seen at the torus uterinus and along the uterosacral ligaments, which may or may not contain T1 hyperintense hemorrhagic foci or T2 hyperintense glands. Other findings may include T2 hypointense obliteration of the fat planes anteriorly to the rectum/sigmoid colon, posteriorly to the vaginal wall or cervix, and obliteration the pouch of Douglas. The sensitivity, specificity, PPV, NPV, and accuracy of MRI for deep pelvic endometriosis were 90.3%, 91%, 92.1%, 89%, and 90.8%, respectively [28]. US Duplex Doppler Pelvis Doppler US imaging is integral for evaluation of abnormal vascularity (in case of inflammation) or lack of vascularity (in case of ovarian torsion). This document considers Doppler imaging to be a standard component of pelvic US.

Acute Pelvic Pain in the Reproductive Age Group. MRI with DWI and contrast-enhanced sequences showed a sensitivity of 83.3% for ovarian torsion, 100% for endometriotic cysts, 100% for hemorrhagic cysts, 83.3% for TOA, and 87.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of MRI in these pathological entities was 94.6% [26]. A TOA is characterized by an ill-defined adnexal mass with thick regular or irregular enhanced walls containing fluid. The signal intensity was variable from low signal intensity on T1-weighted images to intermediate or high signal intensity on T2-weighted images. The solid component (if present) may include thickened septa or wall, papillary projection, and various degrees of solid portions, which enhance after contrast injection. The sensitivity, specificity, PPV, NPV, and accuracy of MRI findings for predicting TOA were 47.1%, 91.4%, 84.2%, 64%, and 69.6%, respectively, in the absence of DWI and apparent diffusion coefficient (ADC) values [27]. Deep pelvic endometriosis may be identified as T2 hypointense fibrosis, most commonly seen at the torus uterinus and along the uterosacral ligaments, which may or may not contain T1 hyperintense hemorrhagic foci or T2 hyperintense glands. Other findings may include T2 hypointense obliteration of the fat planes anteriorly to the rectum/sigmoid colon, posteriorly to the vaginal wall or cervix, and obliteration the pouch of Douglas. The sensitivity, specificity, PPV, NPV, and accuracy of MRI for deep pelvic endometriosis were 90.3%, 91%, 92.1%, 89%, and 90.8%, respectively [28]. US Duplex Doppler Pelvis Doppler US imaging is integral for evaluation of abnormal vascularity (in case of inflammation) or lack of vascularity (in case of ovarian torsion). This document considers Doppler imaging to be a standard component of pelvic US.

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Acute Pelvic Pain in the Reproductive Age Group

A meta-analysis reported a similar pooled sensitivity and specificity in diagnosing adnexal torsion using Doppler US (7 studies, 845 patients, sensitivity 80% and specificity 88%) compared with the grayscale US only (12 studies, 1,187 patients, sensitivity 79% and specificity 76%) [22]. Ovarian torsion may lead to adnexal necrosis and infertility, so early detection is essential. A prospective study on 159 patients showed that all patients with adnexal torsion had absent flow or abnormal flow pattern in the ovarian Acute Pelvic Pain in the Reproductive Age Group vein. In 13 patients whose only abnormality was absent or abnormal ovarian venous flow with normal grayscale US appearance and normal arterial blood flow, 8 of those patients (62%) had adnexal torsion or subtorsion [29]. In cases of adnexal torsion, a whirlpool sign can be located either lateral or medial to the affected ovary. A larger volume of the ovarian or paraovarian mass was associated with a greater probability of a lateral whirlpool sign in a small retrospective study of 30 patients [30]. A retrospective study of 22 patients evaluated for adnexal torsion with whirlpool sign on US, 90.0% of whom had adnexal torsion confirmed on laparoscopy [31]. Power Doppler TVUS was 100% sensitive and 80% specific in PID diagnosis (overall accuracy 93% in a study of 30 patients with PID and 20 patients with hydrosalpinx as a control group) [32]. Specific US signs of PID, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, discriminated patients with acute PID from the control group of patients with hydrosalpinx. Doppler US findings of hyperemia and lower pulsatility index allowed further discrimination between PID and hydrosalpinx with a high level of significance (P < . 01) [32]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible.

Acute Pelvic Pain in the Reproductive Age Group. A meta-analysis reported a similar pooled sensitivity and specificity in diagnosing adnexal torsion using Doppler US (7 studies, 845 patients, sensitivity 80% and specificity 88%) compared with the grayscale US only (12 studies, 1,187 patients, sensitivity 79% and specificity 76%) [22]. Ovarian torsion may lead to adnexal necrosis and infertility, so early detection is essential. A prospective study on 159 patients showed that all patients with adnexal torsion had absent flow or abnormal flow pattern in the ovarian Acute Pelvic Pain in the Reproductive Age Group vein. In 13 patients whose only abnormality was absent or abnormal ovarian venous flow with normal grayscale US appearance and normal arterial blood flow, 8 of those patients (62%) had adnexal torsion or subtorsion [29]. In cases of adnexal torsion, a whirlpool sign can be located either lateral or medial to the affected ovary. A larger volume of the ovarian or paraovarian mass was associated with a greater probability of a lateral whirlpool sign in a small retrospective study of 30 patients [30]. A retrospective study of 22 patients evaluated for adnexal torsion with whirlpool sign on US, 90.0% of whom had adnexal torsion confirmed on laparoscopy [31]. Power Doppler TVUS was 100% sensitive and 80% specific in PID diagnosis (overall accuracy 93% in a study of 30 patients with PID and 20 patients with hydrosalpinx as a control group) [32]. Specific US signs of PID, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, discriminated patients with acute PID from the control group of patients with hydrosalpinx. Doppler US findings of hyperemia and lower pulsatility index allowed further discrimination between PID and hydrosalpinx with a high level of significance (P < . 01) [32]. US Pelvis Transvaginal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible.

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Acute Pelvic Pain in the Reproductive Age Group

TVUS and TAUS of the pelvis is the most useful imaging modality for initial assessment when an obstetrical or gynecological etiology is suspected [13]. A combined transabdominal and transvaginal approach is typically used for pelvic US imaging. TVUS demonstrated a sensitivity of 83.3% for ovarian torsion, 84% for endometriotic cyst, 88.2% for hemorrhagic cysts, 58.3% for TOA, and 62.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of TVUS for these pathological entities was 78.4% [26]. For the diagnosis of adnexal torsion with US, a meta-analysis of 12 studies including 1,187 patients reported a pooled sensitivity of 79% and a pooled specificity of 76%, with negative and positive likelihood ratios of 0.29 and 4.35, respectively [22]. Signs of ovarian torsion on US have varying accuracy: the sensitivity and specificity are 21% and 100% for ovarian tissue edema; 52% and 91% for absence of intraovarian vascularity; 76% and 99% for absence of arterial flow; and 100% and 97% for absence or abnormal venous flow [29]. Other signs indicating torsion are a unilaterally enlarged ovary with central afollicular stroma and multiple uniform 8 to 12 mm peripheral follicles (found in up to 74% of cases); ovarian enlargement is defined as a maximal ovarian dimension of >4 cm or volume >20 cm3 in a premenopausal patient. However, up to 5% of torsed ovaries have been reported to be of normal size [21]. PID can be difficult to diagnose because the symptoms are often subtle and mild. In a small prospective study of 52 patients, the detection rate of moderate-to-severe salpingitis with US was 100%, compared with 25% in the case of mild salpingitis. Bilateral adnexal masses were seen 82% of the time in patients with PID versus 17% for those with other diagnoses. The positive likelihood ratio was 4.8, and the negative likelihood ratio was 0.22.

Acute Pelvic Pain in the Reproductive Age Group. TVUS and TAUS of the pelvis is the most useful imaging modality for initial assessment when an obstetrical or gynecological etiology is suspected [13]. A combined transabdominal and transvaginal approach is typically used for pelvic US imaging. TVUS demonstrated a sensitivity of 83.3% for ovarian torsion, 84% for endometriotic cyst, 88.2% for hemorrhagic cysts, 58.3% for TOA, and 62.5% for dermoid cysts in a prospective study on 74 patients evaluated with TVUS and MRI. Overall sensitivity of TVUS for these pathological entities was 78.4% [26]. For the diagnosis of adnexal torsion with US, a meta-analysis of 12 studies including 1,187 patients reported a pooled sensitivity of 79% and a pooled specificity of 76%, with negative and positive likelihood ratios of 0.29 and 4.35, respectively [22]. Signs of ovarian torsion on US have varying accuracy: the sensitivity and specificity are 21% and 100% for ovarian tissue edema; 52% and 91% for absence of intraovarian vascularity; 76% and 99% for absence of arterial flow; and 100% and 97% for absence or abnormal venous flow [29]. Other signs indicating torsion are a unilaterally enlarged ovary with central afollicular stroma and multiple uniform 8 to 12 mm peripheral follicles (found in up to 74% of cases); ovarian enlargement is defined as a maximal ovarian dimension of >4 cm or volume >20 cm3 in a premenopausal patient. However, up to 5% of torsed ovaries have been reported to be of normal size [21]. PID can be difficult to diagnose because the symptoms are often subtle and mild. In a small prospective study of 52 patients, the detection rate of moderate-to-severe salpingitis with US was 100%, compared with 25% in the case of mild salpingitis. Bilateral adnexal masses were seen 82% of the time in patients with PID versus 17% for those with other diagnoses. The positive likelihood ratio was 4.8, and the negative likelihood ratio was 0.22.

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Acute Pelvic Pain in the Reproductive Age Group

In cases of salpingitis, the masses lying adjacent to the ovaries were on average 2 to 3 cm in diameter, solid (n = 14), unilocular cystic (n = 4), multilocular cystic (n = 3), or multilocular solid (n = 1), with thick walls and well vascularized at color Doppler [33]. Other specific TVUS findings, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, differentiated patients with PID from the control group of hydrosalpinx [32]. Pelvic US has a reported sensitivity of 93% and a specificity of 98% for identification of TOA, a complication of PID. A tubo-ovarian complex is an inflammatory pelvic mass with no pus collection in which adherent, inflamed, edematous ovary, and tubes cannot be separated with the endovaginal probe. TOA demonstrates loss of the normal boundaries of the structures by pus-filled tissue with typical features of complex adnexal mass of varying echogenicity with debris, septations, and irregular margins. Other findings of TOA are pyosalpinx and loculated and speckled echogenic fluid in the cul-de-sac [35]. Evaluation of endometriosis in 104 patients revealed, with respect to rectosigmoid and retrocervical sites, a sensitivity of 98% and 95%, a specificity of 100% and 98%, a PPV of 100% and 98%, an NPV of 98% and 97%, and an accuracy of 99% and 97% with TVUS, demonstrating better results than MRI [36]. A small retrospective case series of 8 pregnant patients with inconclusive findings on MRI and persistent or worsening severe abdominal pain found CT of the abdomen and pelvis useful to diagnose internal hernia, intestinal volvulus, perforation of acute appendicitis, and hemoperitoneum. However, only 75% of these patients received IV contrast for their imaging study [38]. MRI abdomen and pelvis may be appropriate if index of suspicion is high for appendicitis or bowel abnormalities, especially late in pregnancy.

Acute Pelvic Pain in the Reproductive Age Group. In cases of salpingitis, the masses lying adjacent to the ovaries were on average 2 to 3 cm in diameter, solid (n = 14), unilocular cystic (n = 4), multilocular cystic (n = 3), or multilocular solid (n = 1), with thick walls and well vascularized at color Doppler [33]. Other specific TVUS findings, including wall thickness >5 mm, cogwheel sign, incomplete septa, and the presence of cul-de-sac fluid, differentiated patients with PID from the control group of hydrosalpinx [32]. Pelvic US has a reported sensitivity of 93% and a specificity of 98% for identification of TOA, a complication of PID. A tubo-ovarian complex is an inflammatory pelvic mass with no pus collection in which adherent, inflamed, edematous ovary, and tubes cannot be separated with the endovaginal probe. TOA demonstrates loss of the normal boundaries of the structures by pus-filled tissue with typical features of complex adnexal mass of varying echogenicity with debris, septations, and irregular margins. Other findings of TOA are pyosalpinx and loculated and speckled echogenic fluid in the cul-de-sac [35]. Evaluation of endometriosis in 104 patients revealed, with respect to rectosigmoid and retrocervical sites, a sensitivity of 98% and 95%, a specificity of 100% and 98%, a PPV of 100% and 98%, an NPV of 98% and 97%, and an accuracy of 99% and 97% with TVUS, demonstrating better results than MRI [36]. A small retrospective case series of 8 pregnant patients with inconclusive findings on MRI and persistent or worsening severe abdominal pain found CT of the abdomen and pelvis useful to diagnose internal hernia, intestinal volvulus, perforation of acute appendicitis, and hemoperitoneum. However, only 75% of these patients received IV contrast for their imaging study [38]. MRI abdomen and pelvis may be appropriate if index of suspicion is high for appendicitis or bowel abnormalities, especially late in pregnancy.

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Acute Pelvic Pain in the Reproductive Age Group

The rate of nonvisualization of the appendix on MRI is lower than US and reported to be 30.9% in a retrospective cohort study of 171 pregnant patients. Patients with nonvisualization of the appendix on MRI were more likely to be beyond the first trimester [40]. Evaluation for appendicitis with pelvic MRI in 51 pregnant patients for which a previous US did not demonstrate the appendix showed an overall sensitivity of 100%, a specificity of 93.6%, and a prevalence-adjusted PPV and NPV of 1.4% and 100%, respectively, with an accuracy of 94.0% [41]. Another recent study in 49 pregnant patients showed that in 88% of patients, appendicitis was ruled out, and surgery was prevented when MRI was performed after inconclusive US. MRI diagnosed all cases with acute appendicitis, with one case remaining inconclusive. The overall statistical performance of MRI shows a similar NPV of 100% with PPV of 83.3% [42]. Visualization of the normal appendix on MRI may be sometimes challenging. However, a retrospective study in 58 pregnant patients with suspected appendicitis showed that if MRI study was of sufficient diagnostic quality, with no ancillary signs of appendicitis, there were no cases of acute appendicitis. This was true despite the lack of visualization of the appendix in up to 50% of cases by at least 1 of 3 radiologists participating in the study. Therefore, if appendix is not visualized, the recommendation for interpretation is to word the report as low risk for appendicitis rather than indeterminate for excluding appendicitis [43]. The T1 bright appendix sign, defined as a high-intensity signal filling more than half the length of the appendix on T1-weighted imaging, was shown to be a specific sign for a normal appendix in a retrospective study of 125 pregnant patients. The sensitivity, specificity, PPV, and NPV are 44.9%, 95.5%, 97.6%, and 30.0%, respectively.

Acute Pelvic Pain in the Reproductive Age Group. The rate of nonvisualization of the appendix on MRI is lower than US and reported to be 30.9% in a retrospective cohort study of 171 pregnant patients. Patients with nonvisualization of the appendix on MRI were more likely to be beyond the first trimester [40]. Evaluation for appendicitis with pelvic MRI in 51 pregnant patients for which a previous US did not demonstrate the appendix showed an overall sensitivity of 100%, a specificity of 93.6%, and a prevalence-adjusted PPV and NPV of 1.4% and 100%, respectively, with an accuracy of 94.0% [41]. Another recent study in 49 pregnant patients showed that in 88% of patients, appendicitis was ruled out, and surgery was prevented when MRI was performed after inconclusive US. MRI diagnosed all cases with acute appendicitis, with one case remaining inconclusive. The overall statistical performance of MRI shows a similar NPV of 100% with PPV of 83.3% [42]. Visualization of the normal appendix on MRI may be sometimes challenging. However, a retrospective study in 58 pregnant patients with suspected appendicitis showed that if MRI study was of sufficient diagnostic quality, with no ancillary signs of appendicitis, there were no cases of acute appendicitis. This was true despite the lack of visualization of the appendix in up to 50% of cases by at least 1 of 3 radiologists participating in the study. Therefore, if appendix is not visualized, the recommendation for interpretation is to word the report as low risk for appendicitis rather than indeterminate for excluding appendicitis [43]. The T1 bright appendix sign, defined as a high-intensity signal filling more than half the length of the appendix on T1-weighted imaging, was shown to be a specific sign for a normal appendix in a retrospective study of 125 pregnant patients. The sensitivity, specificity, PPV, and NPV are 44.9%, 95.5%, 97.6%, and 30.0%, respectively.

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Acute Pelvic Pain in the Reproductive Age Group

In this study, all 4 patients with a borderline size appendix with appendicitis showed negative T1 bright appendix sign [44]. The addition of DWI showed no significant improvement to MRI detection of appendicitis in a retrospective study of 125 pregnant patients [45]. Evaluation of urinary causes of pain in pregnant patients can be performed with static-fluid MR urography without gadolinium administration. Physiological hydronephrosis can be diagnosed by extrinsic compression of the middle third of the ureter by a gravid uterus, no filling defect, and a collapsed ureter below it; whereas ureteral obstruction by a calculus can demonstrate renal edema or perirenal/periureteral fluid, and in cases with distal calculi, MR urography would show a double kink sign with constriction at the pelvic brim and at the vesicoureteral junction with a standing column of urine in the pelvic ureter. Small calculi were only identified using high resolution T2- weighted sequences [46]. Evaluation for pelvic deep vein thrombosis is limited with Doppler US, as demonstrated in a small study of 27 patients with median gestational age of 29 weeks in which 3 cases of pelvic deep vein thrombosis were diagnosed with time-of-flight MRI sequences after normal US. Deep vein thrombosis was extending more cranially into the pelvis in 65% of women than on the US, suggesting that MRI has an important role as a complementary technique in diagnosing deep vein thrombosis during pregnancy [47]. Acute Pelvic Pain in the Reproductive Age Group US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible. The sensitivity, specificity, and accuracy of abdominal US for the diagnosis of appendicitis in 38 pregnant patients were 61.2%, 80%, and 63.8%, respectively [48].

Acute Pelvic Pain in the Reproductive Age Group. In this study, all 4 patients with a borderline size appendix with appendicitis showed negative T1 bright appendix sign [44]. The addition of DWI showed no significant improvement to MRI detection of appendicitis in a retrospective study of 125 pregnant patients [45]. Evaluation of urinary causes of pain in pregnant patients can be performed with static-fluid MR urography without gadolinium administration. Physiological hydronephrosis can be diagnosed by extrinsic compression of the middle third of the ureter by a gravid uterus, no filling defect, and a collapsed ureter below it; whereas ureteral obstruction by a calculus can demonstrate renal edema or perirenal/periureteral fluid, and in cases with distal calculi, MR urography would show a double kink sign with constriction at the pelvic brim and at the vesicoureteral junction with a standing column of urine in the pelvic ureter. Small calculi were only identified using high resolution T2- weighted sequences [46]. Evaluation for pelvic deep vein thrombosis is limited with Doppler US, as demonstrated in a small study of 27 patients with median gestational age of 29 weeks in which 3 cases of pelvic deep vein thrombosis were diagnosed with time-of-flight MRI sequences after normal US. Deep vein thrombosis was extending more cranially into the pelvis in 65% of women than on the US, suggesting that MRI has an important role as a complementary technique in diagnosing deep vein thrombosis during pregnancy [47]. Acute Pelvic Pain in the Reproductive Age Group US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible. The sensitivity, specificity, and accuracy of abdominal US for the diagnosis of appendicitis in 38 pregnant patients were 61.2%, 80%, and 63.8%, respectively [48].

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Acute Pelvic Pain in the Reproductive Age Group

US performance for the evaluation of appendicitis in pregnant patients appears to be similar to the same-age nonpregnant patients, as shown in a case-control study with 67 pregnant patients compared with 133 nonpregnant young patients. PPV was 94% in the pregnant group and 91% in the nonpregnant group, with corresponding NPV of 40% and 43% [49]. This is even though the appendix is not visualized on US in 68% to 97% of patients [40]. US with graded compression of the appendix has similar accuracy to nonenhanced CT; however, it is more limited in the third trimester due to the large size of the gravid uterus [39]. This may be a useful initial imaging approach if pregnancy location and gestational age are unknown at the time of an acute presentation. US Duplex Doppler Adnexa A combined transabdominal and TVUS approach is typically used for pelvic US imaging. This document considers Doppler imaging to be a standard component of pelvic US. In a recent single-center retrospective study of 790 patients, CT of the abdomen and pelvis with IV contrast demonstrated a statistically significant improved yield (ie, a study with no indeterminate findings) of 97.5% compared with US of 15.8%. The negative appendectomy rate was also significantly lower at 3.3% for the CT group in comparison with 17.7% with US diagnosis [51]. With the increased interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths are important to detect. Higher failure rates of conservative management are seen in the presence of appendicoliths. Furthermore, appendicoliths are associated with increased inflammation and risk of perforation. Appendicoliths are readily identified with CT and found in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis [52].

Acute Pelvic Pain in the Reproductive Age Group. US performance for the evaluation of appendicitis in pregnant patients appears to be similar to the same-age nonpregnant patients, as shown in a case-control study with 67 pregnant patients compared with 133 nonpregnant young patients. PPV was 94% in the pregnant group and 91% in the nonpregnant group, with corresponding NPV of 40% and 43% [49]. This is even though the appendix is not visualized on US in 68% to 97% of patients [40]. US with graded compression of the appendix has similar accuracy to nonenhanced CT; however, it is more limited in the third trimester due to the large size of the gravid uterus [39]. This may be a useful initial imaging approach if pregnancy location and gestational age are unknown at the time of an acute presentation. US Duplex Doppler Adnexa A combined transabdominal and TVUS approach is typically used for pelvic US imaging. This document considers Doppler imaging to be a standard component of pelvic US. In a recent single-center retrospective study of 790 patients, CT of the abdomen and pelvis with IV contrast demonstrated a statistically significant improved yield (ie, a study with no indeterminate findings) of 97.5% compared with US of 15.8%. The negative appendectomy rate was also significantly lower at 3.3% for the CT group in comparison with 17.7% with US diagnosis [51]. With the increased interest in nonoperative antibiotic management of uncomplicated appendicitis, appendicoliths are important to detect. Higher failure rates of conservative management are seen in the presence of appendicoliths. Furthermore, appendicoliths are associated with increased inflammation and risk of perforation. Appendicoliths are readily identified with CT and found in nearly 40% of adults with proven appendicitis, compared with slightly more than 4% of those without appendicitis [52].

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Acute Pelvic Pain in the Reproductive Age Group

In another study, 84% of cases with noninflamed appendix showed luminal filling when positive oral contrast reaches the cecum, thus excluding diagnosis of appendicitis with high certainty. Therefore, the use of positive oral contrast may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis. No appendix filling with contrast was noted in proven acute appendicitis cases [53]. Diluted oral contrast with 1-hour or 3-hour regimens has a similar diagnostic performance [54]. Nevertheless, no difference was found in the sensitivity, specificity, or average interpretation time when neutral oral contrast was administered compared with positive oral contrast [55]. Single-institution randomized trials showed that low-dose CT was noninferior to standard-dose CT in regard to the negative appendectomy rate, the appendiceal perforation rate, or the proportion of patients needing additional imaging tests [56,57]. CT Abdomen and Pelvis Without IV Contrast CT of the abdomen and pelvis without IV contrast remains a useful tool for the diagnosis of appendicitis. Evaluation for appendicitis with a nonenhanced CT was shown to be conclusive in up to 75% of cases in a study of 536 patients, with a reported sensitivity, specificity, PPV, and NPV of 90%, 96%, 84.8%, and 97.4%, respectively. However, in the 132 (25%) inconclusive cases (ie, no definitive diagnosis of appendicitis or normal appendix), the initial noncontrast CT study was followed by contrast-enhanced CT with a sensitivity, specificity PPV, and NPV of 95.6%, 92.3%, 73%, and 99%, respectively [58]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of appendicitis and renal obstruction.

Acute Pelvic Pain in the Reproductive Age Group. In another study, 84% of cases with noninflamed appendix showed luminal filling when positive oral contrast reaches the cecum, thus excluding diagnosis of appendicitis with high certainty. Therefore, the use of positive oral contrast may augment diagnostic accuracy and confidence in cases of suspected acute appendicitis. No appendix filling with contrast was noted in proven acute appendicitis cases [53]. Diluted oral contrast with 1-hour or 3-hour regimens has a similar diagnostic performance [54]. Nevertheless, no difference was found in the sensitivity, specificity, or average interpretation time when neutral oral contrast was administered compared with positive oral contrast [55]. Single-institution randomized trials showed that low-dose CT was noninferior to standard-dose CT in regard to the negative appendectomy rate, the appendiceal perforation rate, or the proportion of patients needing additional imaging tests [56,57]. CT Abdomen and Pelvis Without IV Contrast CT of the abdomen and pelvis without IV contrast remains a useful tool for the diagnosis of appendicitis. Evaluation for appendicitis with a nonenhanced CT was shown to be conclusive in up to 75% of cases in a study of 536 patients, with a reported sensitivity, specificity, PPV, and NPV of 90%, 96%, 84.8%, and 97.4%, respectively. However, in the 132 (25%) inconclusive cases (ie, no definitive diagnosis of appendicitis or normal appendix), the initial noncontrast CT study was followed by contrast-enhanced CT with a sensitivity, specificity PPV, and NPV of 95.6%, 92.3%, 73%, and 99%, respectively [58]. MRI Abdomen and Pelvis Without and With IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without and with IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of appendicitis and renal obstruction.

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Acute Pelvic Pain in the Reproductive Age Group

In a small study of 51 patients, a combination of DWI and T2-weighted images increased the accuracy for the diagnosis of appendicitis, with decreased ADC values correlating with appendicitis. The presence of low ADC in the peri-appendiceal fat was also notable in the presence of complicated appendicitis [63]. That is contrary to the study of 125 pregnant patients in which the addition of DWI showed no significant improvement to MRI detection of appendicitis [45]. MRI performed similarly to abdominal US, followed by abdominal and pelvic CT if findings on US were negative or inconclusive for the detection of perforated appendicitis with low sensitivities (57% for MRI and 48% for US followed by the conditional CT). The missed diagnoses of perforated appendicitis were misclassified as simple appendicitis [64]. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of 13 Acute Pelvic Pain in the Reproductive Age Group appendicitis and renal obstruction. MR urogram without IV contrast was shown to have a 95% sensitivity and 100% specificity for the detection of hydronephrosis, and it has good agreement to determine the level of obstruction as compared to IV urography. The correct diagnosis was made in 94% of patients with MR urogram without IV contrast [65]. US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible.

Acute Pelvic Pain in the Reproductive Age Group. In a small study of 51 patients, a combination of DWI and T2-weighted images increased the accuracy for the diagnosis of appendicitis, with decreased ADC values correlating with appendicitis. The presence of low ADC in the peri-appendiceal fat was also notable in the presence of complicated appendicitis [63]. That is contrary to the study of 125 pregnant patients in which the addition of DWI showed no significant improvement to MRI detection of appendicitis [45]. MRI performed similarly to abdominal US, followed by abdominal and pelvic CT if findings on US were negative or inconclusive for the detection of perforated appendicitis with low sensitivities (57% for MRI and 48% for US followed by the conditional CT). The missed diagnoses of perforated appendicitis were misclassified as simple appendicitis [64]. MRI Abdomen and Pelvis Without IV Contrast There is no relevant literature to support the use of MRI abdomen and pelvis without IV contrast as the initial imaging modality for the evaluation of acute pelvic pain. However, MRI can be useful for equivocal cases of 13 Acute Pelvic Pain in the Reproductive Age Group appendicitis and renal obstruction. MR urogram without IV contrast was shown to have a 95% sensitivity and 100% specificity for the detection of hydronephrosis, and it has good agreement to determine the level of obstruction as compared to IV urography. The correct diagnosis was made in 94% of patients with MR urogram without IV contrast [65]. US Abdomen and Pelvis Transabdominal A combined transabdominal and transvaginal approach is typically used for pelvic US imaging, and both should be performed when possible. A transabdominal-only approach for the pelvis could serve as an alternative if the transvaginal approach is not feasible.

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Acute Pelvic Pain in the Reproductive Age Group

US may be used for the evaluation of suspected appendicitis in adults with a pooled sensitivity of 83% (95% confidence interval [CI], 78%-87%) and a pooled specificity of 93% (95% CI, 90%- 96%), as shown in a meta-analysis of 31 studies with 4,341 patients. In the meta-analysis, CT demonstrated a higher pooled sensitivity of 94% (95% CI, 92%-95%) and a similar specificity of 94% (95% CI, 92%-95%) in that study [50]. In low pretest probability populations, a negative or equivocal US for appendicitis can be used with confidence to exclude this condition without the need for further imaging, with an NPV of 100% and 96%, respectively. However, in cases of moderate or high pretest probability of acute appendicitis and equivocal US, the sensitivity of the US falls to 63% and, thus, should not be solely used to exclude appendicitis [66]. A combination of abdominal US and clinical features successfully predicted uncomplicated appendicitis in 94% of 678 patients in a retrospective cohort study [67]. Evaluation for appendicitis with graded compression of the appendix increases specificity and decreases negative appendectomy rates, as shown in a retrospective study of more than 1,000 patients, with a sensitivity of 83%, a specificity of 100%, and a negative appendectomy rate of 8.4% [68]. Evaluation of renal stones with US is limited. A study of 50 patients demonstrated a sensitivity of 52% to 57% in the right kidney and 32% to 39% in the left kidney when compared with CT for detection of renal stones by US. This study also showed no significant impact of body mass index on the detection of renal stones [69]. A multicentric study of 144 patients showed that in 75% of cases, the presence or absence of hydronephrosis on US correctly predicted the presence or absence of a ureteral stone on CT. Hydronephrosis on US had a PPV of 77% for the presence of a ureteral stone and an NPV of 71% for the absence of a ureteral stone [70].

Acute Pelvic Pain in the Reproductive Age Group. US may be used for the evaluation of suspected appendicitis in adults with a pooled sensitivity of 83% (95% confidence interval [CI], 78%-87%) and a pooled specificity of 93% (95% CI, 90%- 96%), as shown in a meta-analysis of 31 studies with 4,341 patients. In the meta-analysis, CT demonstrated a higher pooled sensitivity of 94% (95% CI, 92%-95%) and a similar specificity of 94% (95% CI, 92%-95%) in that study [50]. In low pretest probability populations, a negative or equivocal US for appendicitis can be used with confidence to exclude this condition without the need for further imaging, with an NPV of 100% and 96%, respectively. However, in cases of moderate or high pretest probability of acute appendicitis and equivocal US, the sensitivity of the US falls to 63% and, thus, should not be solely used to exclude appendicitis [66]. A combination of abdominal US and clinical features successfully predicted uncomplicated appendicitis in 94% of 678 patients in a retrospective cohort study [67]. Evaluation for appendicitis with graded compression of the appendix increases specificity and decreases negative appendectomy rates, as shown in a retrospective study of more than 1,000 patients, with a sensitivity of 83%, a specificity of 100%, and a negative appendectomy rate of 8.4% [68]. Evaluation of renal stones with US is limited. A study of 50 patients demonstrated a sensitivity of 52% to 57% in the right kidney and 32% to 39% in the left kidney when compared with CT for detection of renal stones by US. This study also showed no significant impact of body mass index on the detection of renal stones [69]. A multicentric study of 144 patients showed that in 75% of cases, the presence or absence of hydronephrosis on US correctly predicted the presence or absence of a ureteral stone on CT. Hydronephrosis on US had a PPV of 77% for the presence of a ureteral stone and an NPV of 71% for the absence of a ureteral stone [70].

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acrac_3158181_0

Suspected Retroperitoneal Bleed

Introduction/Background Retroperitoneal bleeding is a hemorrhage into the retroperitoneal space, the space located posterior to the parietal peritoneum and anterior to the transversalis fascia. Retroperitoneal bleeding can occur spontaneously (Wunderlich syndrome), including in association with anticoagulation therapies, or be secondary to trauma, aortic rupture, or bleeding from a visceral vessel or mass. Retroperitoneal bleeding can also be iatrogenic, as a complication from surgeries or transfemoral catheterization procedures [1,2]. The retroperitoneum contains a portion of the duodenum, kidneys, adrenal glands, proximal ureters, pancreas, and vascular structures, including the abdominal aorta and proximal renal vasculature. This anatomy provides a variable source of potential bleeding. In the setting of trauma, retroperitoneal bleeding can also be the result of pelvic or spine fractures. Recognition of retroperitoneal bleeding from pelvic fractures is important given that it is associated with an increased need for transfusions and rapid intervention [3]. Vascular bleeding in the retroperitoneum can be from aortic aneurysmal rupture or visceral vessel rupture. The latter can be seen, for example, in the setting of pseudoaneurysms secondary to duodenal or pancreatic inflammation or infection [4]. Retroperitoneal bleeding is also the second most common site of major, or clinically relevant, bleeding seen among cancer patients [5]. Bleeding can be due to the malignancy itself or interventions and treatment, including surgery, upper endoscopy, chemotherapy, or anticoagulation. The many causes for retroperitoneal bleeding can make the diagnosis and management clinically challenging. Assessing for the clinical signs of retroperitoneal bleeding can be difficult given that the location of bleeding is not readily accessible to physical examination and often has an obscured etiology. This can result in the delayed diagnosis of retroperitoneal bleeding [6,7].

Suspected Retroperitoneal Bleed. Introduction/Background Retroperitoneal bleeding is a hemorrhage into the retroperitoneal space, the space located posterior to the parietal peritoneum and anterior to the transversalis fascia. Retroperitoneal bleeding can occur spontaneously (Wunderlich syndrome), including in association with anticoagulation therapies, or be secondary to trauma, aortic rupture, or bleeding from a visceral vessel or mass. Retroperitoneal bleeding can also be iatrogenic, as a complication from surgeries or transfemoral catheterization procedures [1,2]. The retroperitoneum contains a portion of the duodenum, kidneys, adrenal glands, proximal ureters, pancreas, and vascular structures, including the abdominal aorta and proximal renal vasculature. This anatomy provides a variable source of potential bleeding. In the setting of trauma, retroperitoneal bleeding can also be the result of pelvic or spine fractures. Recognition of retroperitoneal bleeding from pelvic fractures is important given that it is associated with an increased need for transfusions and rapid intervention [3]. Vascular bleeding in the retroperitoneum can be from aortic aneurysmal rupture or visceral vessel rupture. The latter can be seen, for example, in the setting of pseudoaneurysms secondary to duodenal or pancreatic inflammation or infection [4]. Retroperitoneal bleeding is also the second most common site of major, or clinically relevant, bleeding seen among cancer patients [5]. Bleeding can be due to the malignancy itself or interventions and treatment, including surgery, upper endoscopy, chemotherapy, or anticoagulation. The many causes for retroperitoneal bleeding can make the diagnosis and management clinically challenging. Assessing for the clinical signs of retroperitoneal bleeding can be difficult given that the location of bleeding is not readily accessible to physical examination and often has an obscured etiology. This can result in the delayed diagnosis of retroperitoneal bleeding [6,7].

3158181

acrac_3158181_1

Suspected Retroperitoneal Bleed

Clinically, retroperitoneal bleeding can present with diffuse abdominal, back, or lower quadrant abdominal pain, abdominal distension, and palpation of a flank mass [2,7]. However, these clinical findings are nonspecific for the diagnosis and further contribute to the difficulty in diagnoses. The management of retroperitoneal bleeding depends on the cause and size of bleed, hemodynamic status and stability of the patient, and the presence of active bleeding [6,7]. Treatment options include fluid resuscitation and close monitoring, angiographic embolization, and surgery. Retroperitoneal bleeding of significant volume can be concealed in the potential space and result in hypovolemic shock, necessitating blood transfusions with urgent angiographic or surgical treatment [1]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Suspected Retroperitoneal Bleed All elements are essential: (1) timing, (2) reconstructions/reformats, and (3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Clinically suspected retroperitoneal bleed. Initial imaging. Aortography Abdomen and Pelvis Angiography of the abdomen and pelvis provides the benefit of being able to simultaneously diagnose active bleeding and treat retroperitoneal bleeding with transcatheter arterial embolization (TAE) [9].

Suspected Retroperitoneal Bleed. Clinically, retroperitoneal bleeding can present with diffuse abdominal, back, or lower quadrant abdominal pain, abdominal distension, and palpation of a flank mass [2,7]. However, these clinical findings are nonspecific for the diagnosis and further contribute to the difficulty in diagnoses. The management of retroperitoneal bleeding depends on the cause and size of bleed, hemodynamic status and stability of the patient, and the presence of active bleeding [6,7]. Treatment options include fluid resuscitation and close monitoring, angiographic embolization, and surgery. Retroperitoneal bleeding of significant volume can be concealed in the potential space and result in hypovolemic shock, necessitating blood transfusions with urgent angiographic or surgical treatment [1]. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Suspected Retroperitoneal Bleed All elements are essential: (1) timing, (2) reconstructions/reformats, and (3) 3-D renderings. Standard CTs with contrast also include timing issues and reconstructions/reformats. Only in CTA, however, is 3-D rendering a required element. This corresponds to the definitions that the CMS has applied to the Current Procedural Terminology codes. OR Discussion of Procedures by Variant Variant 1: Clinically suspected retroperitoneal bleed. Initial imaging. Aortography Abdomen and Pelvis Angiography of the abdomen and pelvis provides the benefit of being able to simultaneously diagnose active bleeding and treat retroperitoneal bleeding with transcatheter arterial embolization (TAE) [9].

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acrac_3158181_2

Suspected Retroperitoneal Bleed

Angiography has high spatial and temporal resolution for evaluating vascular structures and the source of the bleed. Initial utilization of aortography of the abdomen and pelvis in patients with clinically suspected retroperitoneal bleed is best reserved for patients who are hemodynamically unstable with a high index of clinical suspicion for retroperitoneal hemorrhage. Urgent aortography may be appropriate in cases of known active arterial bleeding or when there is a known contained vascular injury that would be amendable to concomitant diagnosis and treatment. In a study by Fitzpatrick et al [4] of patients with retroperitoneal bleeding related to pancreatitis, all angiographic cases were diagnostic of the bleeding vessel with TAE, with success measured by observation of cessation of bleeding and clinical stabilization. In that study, cessation of bleeding with embolization was achieved in all cases as determined by observation on angiography. Detection of active bleeding with conventional angiography requires a bleeding rate of 0.5 to 1.0 mL/min. Limitations of angiography also include that it is invasive, and risks include hematoma or bleeding at access site, iatrogenic dissections, and infection [10]. CT Abdomen and Pelvis CT is helpful for the diagnosis of retroperitoneal hematoma given its speed, high spatial resolution, and noninvasiveness. CT can depict blood, localize areas of bleeding, and evaluate for recent or active extravasation of contrast material [7]. Because of its speed and ability to scan large areas, it is especially useful to localize the area of bleeding and identify a possible cause, such as groin access, pelvic fracture, or mass [6]. Noncontrast CT can be appropriate to expeditiously confirm or exclude bleeding and is especially helpful in patients with compromised renal function or when there is concern for additional contrast load if further intervention with angiography may be considered.

Suspected Retroperitoneal Bleed. Angiography has high spatial and temporal resolution for evaluating vascular structures and the source of the bleed. Initial utilization of aortography of the abdomen and pelvis in patients with clinically suspected retroperitoneal bleed is best reserved for patients who are hemodynamically unstable with a high index of clinical suspicion for retroperitoneal hemorrhage. Urgent aortography may be appropriate in cases of known active arterial bleeding or when there is a known contained vascular injury that would be amendable to concomitant diagnosis and treatment. In a study by Fitzpatrick et al [4] of patients with retroperitoneal bleeding related to pancreatitis, all angiographic cases were diagnostic of the bleeding vessel with TAE, with success measured by observation of cessation of bleeding and clinical stabilization. In that study, cessation of bleeding with embolization was achieved in all cases as determined by observation on angiography. Detection of active bleeding with conventional angiography requires a bleeding rate of 0.5 to 1.0 mL/min. Limitations of angiography also include that it is invasive, and risks include hematoma or bleeding at access site, iatrogenic dissections, and infection [10]. CT Abdomen and Pelvis CT is helpful for the diagnosis of retroperitoneal hematoma given its speed, high spatial resolution, and noninvasiveness. CT can depict blood, localize areas of bleeding, and evaluate for recent or active extravasation of contrast material [7]. Because of its speed and ability to scan large areas, it is especially useful to localize the area of bleeding and identify a possible cause, such as groin access, pelvic fracture, or mass [6]. Noncontrast CT can be appropriate to expeditiously confirm or exclude bleeding and is especially helpful in patients with compromised renal function or when there is concern for additional contrast load if further intervention with angiography may be considered.

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Suspected Retroperitoneal Bleed

The attenuation of the hematoma on noncontrast CT can help determine the relative acuity, with high attenuation and mixed attenuation indicating acute to subacute bleeding and rebleeding, and low attenuation suggesting subacute to chronic blood products. Findings such as sentinel clot can be helpful to suggest an area of bleeding if an active blush is not observed at the time of scanning. CT also serves well as the initial examination to follow-up clinically suspected rebleeding or to evaluate for changes in hematoma size or to evaluate for a subsequent complication, such as infection and abscess formation [6]. Given these attributes of CT imaging, it is appropriate for initial imaging in the suspicion of retroperitoneal bleeding. Limitations of CT include the inability to simultaneously intervene. CTA Abdomen and Pelvis CT angiography (CTA) is usually performed to detect the site of active retroperitoneal bleeding in cases of known or clinically suspected acute bleeding. Like CT, CTA provides the exact location of hematoma. CTA has better sensitivity than invasive angiography for detecting active bleeding and is known to detect bleeding rates as low as 0.3 mL/min. In evaluation of active bleeding, Tani et al [9] identified active extravasation of contrast in 78.9% to 84.2% of cases, with a sensitivity in CT for detection of active bleeding of 59.5% and positive predictive value compared to TAE of 62.9% to 71.0%. If the bleeding is intermittent, the sensitivity of CTA decreases. In patients Suspected Retroperitoneal Bleed with a history of aortic aneurysm and suspected rupture as cause of retroperitoneal hematoma, a CTA examination can provide confirmation and valuable preoperative information for endovascular or surgical repair, including size, extent, visceral disease, and anatomic vessel variants [11]. CTA is appropriate in the initial evaluation of bleeding with the benefit of detecting active bleeding and vascular sources.

Suspected Retroperitoneal Bleed. The attenuation of the hematoma on noncontrast CT can help determine the relative acuity, with high attenuation and mixed attenuation indicating acute to subacute bleeding and rebleeding, and low attenuation suggesting subacute to chronic blood products. Findings such as sentinel clot can be helpful to suggest an area of bleeding if an active blush is not observed at the time of scanning. CT also serves well as the initial examination to follow-up clinically suspected rebleeding or to evaluate for changes in hematoma size or to evaluate for a subsequent complication, such as infection and abscess formation [6]. Given these attributes of CT imaging, it is appropriate for initial imaging in the suspicion of retroperitoneal bleeding. Limitations of CT include the inability to simultaneously intervene. CTA Abdomen and Pelvis CT angiography (CTA) is usually performed to detect the site of active retroperitoneal bleeding in cases of known or clinically suspected acute bleeding. Like CT, CTA provides the exact location of hematoma. CTA has better sensitivity than invasive angiography for detecting active bleeding and is known to detect bleeding rates as low as 0.3 mL/min. In evaluation of active bleeding, Tani et al [9] identified active extravasation of contrast in 78.9% to 84.2% of cases, with a sensitivity in CT for detection of active bleeding of 59.5% and positive predictive value compared to TAE of 62.9% to 71.0%. If the bleeding is intermittent, the sensitivity of CTA decreases. In patients Suspected Retroperitoneal Bleed with a history of aortic aneurysm and suspected rupture as cause of retroperitoneal hematoma, a CTA examination can provide confirmation and valuable preoperative information for endovascular or surgical repair, including size, extent, visceral disease, and anatomic vessel variants [11]. CTA is appropriate in the initial evaluation of bleeding with the benefit of detecting active bleeding and vascular sources.

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Suspected Retroperitoneal Bleed

CTA has the same limitations as CT as a diagnostic modality only, not allowing for intervention as with TAE. MRI Abdomen and Pelvis MRI has very high soft-tissue contrast and is very helpful in evaluation of the retroperitoneal structures. However, the length of examination time makes it less than ideal for initial imaging in cases of suspected retroperitoneal bleeding. MRI is helpful in further workup of patients with known hematoma when there is a suspicion of bleeding being from an underlying mass or lesion, such as patients with neoplasm in the pancreas, kidneys, or adrenal glands [12]. MRI in these cases can also be helpful to distinguish anatomically between blood and suspected underlying neoplasm, while characterizing bleeding acuity by differentiating acute and early subacute blood (isointense to hyperintense signal on T1-weighted and dark on T2-weighted sequences) from chronic blood (hypointense signal). MRI can be used to follow size of retroperitoneal hematomas in which sequential examinations may be needed, but the length of examination makes it usually not appropriate for diagnosis of retroperitoneal bleeding when compared to CT for initial diagnosis. Radiography Abdomen and Pelvis Abdominal radiography findings are highly nonspecific and have low sensitivity in detecting retroperitoneal bleeding. Radiography is often the initial examination in patients who present with palpable mass or abdominal pain, without clinical suspicion of hemorrhage as the cause of these clinical signs and symptoms [13]. Radiographs can show displacement of bowel loops or obscuration of the psoas muscle contour if there is large volume of retroperitoneal hematoma. Radiographs can evaluate for mispositioned lines or cannula as the potential etiology of bleeding. Two important limitations of radiography include the inability to evaluate if the bleeding is active or not and the limitation in identification of the source of the bleeding.

Suspected Retroperitoneal Bleed. CTA has the same limitations as CT as a diagnostic modality only, not allowing for intervention as with TAE. MRI Abdomen and Pelvis MRI has very high soft-tissue contrast and is very helpful in evaluation of the retroperitoneal structures. However, the length of examination time makes it less than ideal for initial imaging in cases of suspected retroperitoneal bleeding. MRI is helpful in further workup of patients with known hematoma when there is a suspicion of bleeding being from an underlying mass or lesion, such as patients with neoplasm in the pancreas, kidneys, or adrenal glands [12]. MRI in these cases can also be helpful to distinguish anatomically between blood and suspected underlying neoplasm, while characterizing bleeding acuity by differentiating acute and early subacute blood (isointense to hyperintense signal on T1-weighted and dark on T2-weighted sequences) from chronic blood (hypointense signal). MRI can be used to follow size of retroperitoneal hematomas in which sequential examinations may be needed, but the length of examination makes it usually not appropriate for diagnosis of retroperitoneal bleeding when compared to CT for initial diagnosis. Radiography Abdomen and Pelvis Abdominal radiography findings are highly nonspecific and have low sensitivity in detecting retroperitoneal bleeding. Radiography is often the initial examination in patients who present with palpable mass or abdominal pain, without clinical suspicion of hemorrhage as the cause of these clinical signs and symptoms [13]. Radiographs can show displacement of bowel loops or obscuration of the psoas muscle contour if there is large volume of retroperitoneal hematoma. Radiographs can evaluate for mispositioned lines or cannula as the potential etiology of bleeding. Two important limitations of radiography include the inability to evaluate if the bleeding is active or not and the limitation in identification of the source of the bleeding.

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Suspected Retroperitoneal Bleed

Additionally, up to a moderate volume hematoma may not exert enough mass effect to prompt discovery on radiography. These limitations make radiography usually not appropriate for initial diagnosis of retroperitoneal bleed. RBC Scan Abdomen and Pelvis Tc-99m-labeled red blood cell (RBC) scintigraphy is highly sensitive in detecting active bleeding, with detection of bleeding rates as low as 0.1 mL/min [14]. RBC scintigraphy has been shown to be more sensitive to detect active ongoing bleeding in cases of gastrointestinal location of bleeding that may not be confirmed on CTA, allowing for a localized intervention to occur such as with TAE. However, its utilization in initial suspicion of retroperitoneal bleeding and hematoma is limited and usually not appropriate because of the longer time of examination (from order placement to scan completion) and better sensitivity in the retroperitoneal location provided by other imaging procedures. US Abdomen and Pelvis Ultrasound (US) can be helpful in the overall evaluation of acute patients because of its noninvasiveness and portability [15]. Contrast enhanced US, which utilizes microbubbles of gas in a phospholipid membrane, has been shown to be effective in identifying postsurgical complications, including retroperitoneal hematoma [16]. US performed is 99% sensitive and 98% specific for detecting abdominal aortic aneurysm AAA in the emergency department setting [17]. The speed and accuracy of this approach is therefore useful to detect if abdominal aortic aneurysm is present when a ruptured aneurysm is a differential diagnosis in the emergency or critical care setting. US helps only to detect the presence or absence of abdominal aortic aneurysm, not the presence of rupture, and does not provide significant information regarding alternative etiologies of retroperitoneal bleeding.

Suspected Retroperitoneal Bleed. Additionally, up to a moderate volume hematoma may not exert enough mass effect to prompt discovery on radiography. These limitations make radiography usually not appropriate for initial diagnosis of retroperitoneal bleed. RBC Scan Abdomen and Pelvis Tc-99m-labeled red blood cell (RBC) scintigraphy is highly sensitive in detecting active bleeding, with detection of bleeding rates as low as 0.1 mL/min [14]. RBC scintigraphy has been shown to be more sensitive to detect active ongoing bleeding in cases of gastrointestinal location of bleeding that may not be confirmed on CTA, allowing for a localized intervention to occur such as with TAE. However, its utilization in initial suspicion of retroperitoneal bleeding and hematoma is limited and usually not appropriate because of the longer time of examination (from order placement to scan completion) and better sensitivity in the retroperitoneal location provided by other imaging procedures. US Abdomen and Pelvis Ultrasound (US) can be helpful in the overall evaluation of acute patients because of its noninvasiveness and portability [15]. Contrast enhanced US, which utilizes microbubbles of gas in a phospholipid membrane, has been shown to be effective in identifying postsurgical complications, including retroperitoneal hematoma [16]. US performed is 99% sensitive and 98% specific for detecting abdominal aortic aneurysm AAA in the emergency department setting [17]. The speed and accuracy of this approach is therefore useful to detect if abdominal aortic aneurysm is present when a ruptured aneurysm is a differential diagnosis in the emergency or critical care setting. US helps only to detect the presence or absence of abdominal aortic aneurysm, not the presence of rupture, and does not provide significant information regarding alternative etiologies of retroperitoneal bleeding.

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acrac_3101482_0

Chronic Shoulder Pain PCAs

Special Imaging Considerations Several studies have looked for ways to shorten typical shoulder conventional MRI or MR arthrogram protocols while maintaining diagnostic accuracy. Isotropic 3-D imaging has been increasingly used as a substitute for conventional multiplanar 2-D MRI, with a similar sensitivity and specificity for rotator cuff tear and labral abnormalities at a lower scan time [7,8]. Faster scans can also be performed using 2-D fast spin echo sequences with parallel imaging, which produce similar findings as seen on conventional MRI [9]. OR aPanel Vice-chair, University of Virginia Health System, Charlottesville, Virginia. bPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. cUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. dStanford University, Stanford, California, Primary care physician. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. gUniversity of Nebraska Medical Center, Omaha, Nebraska; American College of Emergency Physicians. hThe Centers for Advanced Orthopaedics, George Washington University, Washington, District of Columbia; American Academy of Orthopaedic Surgeons. iUniversity of Michigan Health System, Ann Arbor, Michigan; Committee on Emergency Radiology-GSER. jDuke University Medical Center, Durham, North Carolina. kUniversity of Missouri Health Care, Columbia, Missouri. lCleveland Clinic, Cleveland, Ohio. mThe University of Texas MD Anderson Cancer Center, Houston, Texas; Commission on Nuclear Medicine and Molecular Imaging. nPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. oSpecialty Chair, VA San Diego Healthcare System, San Diego, California. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels.

Chronic Shoulder Pain PCAs. Special Imaging Considerations Several studies have looked for ways to shorten typical shoulder conventional MRI or MR arthrogram protocols while maintaining diagnostic accuracy. Isotropic 3-D imaging has been increasingly used as a substitute for conventional multiplanar 2-D MRI, with a similar sensitivity and specificity for rotator cuff tear and labral abnormalities at a lower scan time [7,8]. Faster scans can also be performed using 2-D fast spin echo sequences with parallel imaging, which produce similar findings as seen on conventional MRI [9]. OR aPanel Vice-chair, University of Virginia Health System, Charlottesville, Virginia. bPanel Chair, Mayo Clinic Arizona, Phoenix, Arizona. cUniversity of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. dStanford University, Stanford, California, Primary care physician. eMayo Clinic, Rochester, Minnesota. fHospital for Special Surgery, New York, New York. gUniversity of Nebraska Medical Center, Omaha, Nebraska; American College of Emergency Physicians. hThe Centers for Advanced Orthopaedics, George Washington University, Washington, District of Columbia; American Academy of Orthopaedic Surgeons. iUniversity of Michigan Health System, Ann Arbor, Michigan; Committee on Emergency Radiology-GSER. jDuke University Medical Center, Durham, North Carolina. kUniversity of Missouri Health Care, Columbia, Missouri. lCleveland Clinic, Cleveland, Ohio. mThe University of Texas MD Anderson Cancer Center, Houston, Texas; Commission on Nuclear Medicine and Molecular Imaging. nPenn State Milton S. Hershey Medical Center, Hershey, Pennsylvania and Uniformed Services University of the Health Sciences, Bethesda, Maryland. oSpecialty Chair, VA San Diego Healthcare System, San Diego, California. The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels.

3101482

acrac_3101482_1

Chronic Shoulder Pain PCAs

Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Chronic Shoulder Pain Discussion of Procedures by Variant Variant 1: Chronic shoulder pain. Initial imaging. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the initial evaluation of chronic shoulder pain. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the initial evaluation of chronic shoulder pain. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with intravenous (IV) contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the initial evaluation of chronic shoulder pain. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of chronic shoulder pain. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures There is insufficient evidence to support the use of image-guided anesthetic +/- corticosteroid injection of the shoulder in the initial evaluation of chronic shoulder pain. MR Arthrography Shoulder There is insufficient evidence to support the use of MR arthrography shoulder in the initial evaluation of chronic shoulder pain. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain.

Chronic Shoulder Pain PCAs. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Chronic Shoulder Pain Discussion of Procedures by Variant Variant 1: Chronic shoulder pain. Initial imaging. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the initial evaluation of chronic shoulder pain. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the initial evaluation of chronic shoulder pain. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with intravenous (IV) contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the initial evaluation of chronic shoulder pain. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of fluorine-18-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT skull base to mid-thigh in the initial evaluation of chronic shoulder pain. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures There is insufficient evidence to support the use of image-guided anesthetic +/- corticosteroid injection of the shoulder in the initial evaluation of chronic shoulder pain. MR Arthrography Shoulder There is insufficient evidence to support the use of MR arthrography shoulder in the initial evaluation of chronic shoulder pain. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the initial evaluation of chronic shoulder pain.

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Chronic Shoulder Pain PCAs

MRI Shoulder Without IV Contrast There is insufficient evidence to support the use of MRI shoulder without IV contrast in the initial evaluation of chronic shoulder pain. US Shoulder The literature suggests that radiographic evaluation should generally be the first imaging study ordered in patients with shoulder pain [1,10-14]. Some practitioners may use ultrasound (US) as an initial imaging study when rotator cuff disease/impingement is suggested by the clinical examination. Chronic Shoulder Pain Variant 2: Chronic shoulder pain. Suspect rotator cuff disorders or subacromial subdeltoid bursitis (no prior surgery). Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder CT arthrography has shown good diagnostic performance for depicting rotator cuff tendon tears with a reported respective sensitivity and specificity of 99% and 100% for the supraspinatus tendon, 97.4% and 99.5% for the infraspinatus tendon, and 64.7% and 98.2% for the subscapularis tendon [15]. CT arthrography provides a comparable alternative to MR arthrography in the evaluation of rotator cuff tendon tears [16,17]. CT arthrography is able to detect very subtle articular surface cuff defects, but, because of lack of contrast extension from the glenohumeral joint space, it is less effective at demonstrating bursal surface or intrasubstance tears, which are typically well seen with MRI or US [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.

Chronic Shoulder Pain PCAs. MRI Shoulder Without IV Contrast There is insufficient evidence to support the use of MRI shoulder without IV contrast in the initial evaluation of chronic shoulder pain. US Shoulder The literature suggests that radiographic evaluation should generally be the first imaging study ordered in patients with shoulder pain [1,10-14]. Some practitioners may use ultrasound (US) as an initial imaging study when rotator cuff disease/impingement is suggested by the clinical examination. Chronic Shoulder Pain Variant 2: Chronic shoulder pain. Suspect rotator cuff disorders or subacromial subdeltoid bursitis (no prior surgery). Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder CT arthrography has shown good diagnostic performance for depicting rotator cuff tendon tears with a reported respective sensitivity and specificity of 99% and 100% for the supraspinatus tendon, 97.4% and 99.5% for the infraspinatus tendon, and 64.7% and 98.2% for the subscapularis tendon [15]. CT arthrography provides a comparable alternative to MR arthrography in the evaluation of rotator cuff tendon tears [16,17]. CT arthrography is able to detect very subtle articular surface cuff defects, but, because of lack of contrast extension from the glenohumeral joint space, it is less effective at demonstrating bursal surface or intrasubstance tears, which are typically well seen with MRI or US [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.

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Chronic Shoulder Pain PCAs

CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast CT shoulder without IV contrast is of limited utility when evaluating for rotator cuff tear or subacromial subdeltoid bursitis. Noncontrast CT can sometimes demonstrate fatty infiltration of rotator cuff muscles with a corresponding rotator cuff tear, although the overall sensitivity of this finding is low [19]. CT may demonstrate a high-riding humeral head or remodeling of the acromial undersurface in patients with large rotator cuff tears. However, this finding is generally seen on initial radiographs, and CT does not allow for characterization of the underlying tear because CT lacks the soft-tissue contrast resolution necessary to adequately evaluate the rotator cuff tear itself. CT may be able to directly demonstrate some large rotator cuff tears as well as fatty infiltration of the rotator cuff musculature; however, it was found to have a sensitivity of 20% for full thickness rotator cuff tears in one small study [19]. Large amounts of fluid in the subacromial subdeltoid bursa can sometimes be visualized with CT. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Corticosteroid injection is sometimes used before advanced imaging is obtained but may serve as a better diagnostic tool in patients with subacromial subdeltoid bursitis as opposed to those patients with suspected rotator cuff tear.

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast CT shoulder without IV contrast is of limited utility when evaluating for rotator cuff tear or subacromial subdeltoid bursitis. Noncontrast CT can sometimes demonstrate fatty infiltration of rotator cuff muscles with a corresponding rotator cuff tear, although the overall sensitivity of this finding is low [19]. CT may demonstrate a high-riding humeral head or remodeling of the acromial undersurface in patients with large rotator cuff tears. However, this finding is generally seen on initial radiographs, and CT does not allow for characterization of the underlying tear because CT lacks the soft-tissue contrast resolution necessary to adequately evaluate the rotator cuff tear itself. CT may be able to directly demonstrate some large rotator cuff tears as well as fatty infiltration of the rotator cuff musculature; however, it was found to have a sensitivity of 20% for full thickness rotator cuff tears in one small study [19]. Large amounts of fluid in the subacromial subdeltoid bursa can sometimes be visualized with CT. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Corticosteroid injection is sometimes used before advanced imaging is obtained but may serve as a better diagnostic tool in patients with subacromial subdeltoid bursitis as opposed to those patients with suspected rotator cuff tear.

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acrac_3101482_4

Chronic Shoulder Pain PCAs

US image-guided injection with local anesthetic and corticosteroid into the subacromial-subdeltoid bursa has been shown to result in improvement in pain and range of motion in patients with rotator cuff symptoms [20,21]. Subacromial bursal injections are used by some as a diagnostic tool to evaluate for rotator cuff pathology [22], although the diagnostic utility of this approach is unclear in the literature. Glenohumeral joint injection has been found to not have significant diagnostic utility for patients with suspected rotator cuff tear [23]. MR Arthrography Shoulder MR arthrography provides greater sensitivity and specificity compared to conventional MRI in evaluating partial thickness articular surface tears [24-26]. Partial bursal and purely intrasubstance tears should have similar rates of detection on conventional MRI and MR arthrography because the diagnosis is dependent on the same fluid-sensitive sequences [27]. Extension of intra-articular gadolinium into the subacromial subdeltoid bursa can sometimes differentiate a high-grade partial tear from a full thickness tear [28]. However, the advantages of MR arthrography over conventional MRI for detecting rotator cuff tear must be weighed against the invasive nature of the arthrogram procedure [29]. Arthrograms with saline have been shown in some studies to have similar accuracy for rotator cuff tear as those performed with dilute gadolinium [30,31]. Some authors suggest that adding an abduction external rotation imaging position to an MR arthrogram improves the accuracy in diagnosing partial articular surface tears [32,33], although this positioning is often omitted because of patient discomfort. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34].

Chronic Shoulder Pain PCAs. US image-guided injection with local anesthetic and corticosteroid into the subacromial-subdeltoid bursa has been shown to result in improvement in pain and range of motion in patients with rotator cuff symptoms [20,21]. Subacromial bursal injections are used by some as a diagnostic tool to evaluate for rotator cuff pathology [22], although the diagnostic utility of this approach is unclear in the literature. Glenohumeral joint injection has been found to not have significant diagnostic utility for patients with suspected rotator cuff tear [23]. MR Arthrography Shoulder MR arthrography provides greater sensitivity and specificity compared to conventional MRI in evaluating partial thickness articular surface tears [24-26]. Partial bursal and purely intrasubstance tears should have similar rates of detection on conventional MRI and MR arthrography because the diagnosis is dependent on the same fluid-sensitive sequences [27]. Extension of intra-articular gadolinium into the subacromial subdeltoid bursa can sometimes differentiate a high-grade partial tear from a full thickness tear [28]. However, the advantages of MR arthrography over conventional MRI for detecting rotator cuff tear must be weighed against the invasive nature of the arthrogram procedure [29]. Arthrograms with saline have been shown in some studies to have similar accuracy for rotator cuff tear as those performed with dilute gadolinium [30,31]. Some authors suggest that adding an abduction external rotation imaging position to an MR arthrogram improves the accuracy in diagnosing partial articular surface tears [32,33], although this positioning is often omitted because of patient discomfort. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34].

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acrac_3101482_5

Chronic Shoulder Pain PCAs

Indirect MR arthrography has been shown to have a slightly higher specificity for diagnosing articular- surface partial thickness tears of the supraspinatus and infraspinatus tendons, as well as a greater specificity for diagnosing subscapularis tendon tears [35], relative to noncontrast MRI, and has shown high accuracy relative to arthroscopy [36]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast MRI of the shoulder is a highly accurate tool in the assessment of the rotator cuff. MRI findings of tendinopathy consist of intermediate increased signal and tendon thickening [28]. Rotator cuff tears, particularly full thickness tears, can be reliably identified using conventional MRI with high sensitivity and specificity [37-39]. Sensitivity and specificity for detecting partial thickness bursal surface tears is similar for conventional MRI and MR arthrography [27]. Although MR arthrography may have a slightly higher sensitivity and specificity than conventional MRI for diagnosing rotator cuff tears, particularly partial thickness articular surface tears, this difference in accuracy must be weighed against the need for an invasive arthrogram procedure [29]. Tendon retraction, muscle atrophy, and fatty infiltration are associated important findings that are well seen on MRI and predict reparability of rotator cuff tear [40]. Axial images can be helpful in determining rotator cuff tear shape [41], which can aid in the selection of a particular surgical technique. In addition to evaluating the rotator cuff itself, MRI can detect extra-articular abnormalities that may predispose to shoulder impingement such as acromioclavicular degenerative change or a subacromial spur. Fluid accumulation within the subacromial subdeltoid bursa is visualized on MRI and is often a nonspecific finding seen with a rotator cuff tear or an underlying inflammatory disorder [42].

Chronic Shoulder Pain PCAs. Indirect MR arthrography has been shown to have a slightly higher specificity for diagnosing articular- surface partial thickness tears of the supraspinatus and infraspinatus tendons, as well as a greater specificity for diagnosing subscapularis tendon tears [35], relative to noncontrast MRI, and has shown high accuracy relative to arthroscopy [36]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast MRI of the shoulder is a highly accurate tool in the assessment of the rotator cuff. MRI findings of tendinopathy consist of intermediate increased signal and tendon thickening [28]. Rotator cuff tears, particularly full thickness tears, can be reliably identified using conventional MRI with high sensitivity and specificity [37-39]. Sensitivity and specificity for detecting partial thickness bursal surface tears is similar for conventional MRI and MR arthrography [27]. Although MR arthrography may have a slightly higher sensitivity and specificity than conventional MRI for diagnosing rotator cuff tears, particularly partial thickness articular surface tears, this difference in accuracy must be weighed against the need for an invasive arthrogram procedure [29]. Tendon retraction, muscle atrophy, and fatty infiltration are associated important findings that are well seen on MRI and predict reparability of rotator cuff tear [40]. Axial images can be helpful in determining rotator cuff tear shape [41], which can aid in the selection of a particular surgical technique. In addition to evaluating the rotator cuff itself, MRI can detect extra-articular abnormalities that may predispose to shoulder impingement such as acromioclavicular degenerative change or a subacromial spur. Fluid accumulation within the subacromial subdeltoid bursa is visualized on MRI and is often a nonspecific finding seen with a rotator cuff tear or an underlying inflammatory disorder [42].

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acrac_3101482_6

Chronic Shoulder Pain PCAs

Radiography Shoulder Additional Views The rotator cuff tendons cannot be directly assessed radiographically, regardless of the view. Secondary findings of rotator cuff tear such as a high-riding humeral head or changes at the greater tuberosity can be seen on standard radiographic views. There have been several reports assessing special views for the evaluation of potential impingement from the anterior acromion. Outlet views can be used to determine acromial shape and have been shown to be more accurate than a single-slice MRI [43]. The Rockwood and cassette tilt views are angled frontal projections that can be used to detect anterior acromial osteophytes [44]. The subacromial subdeltoid bursa is a soft- tissue potential space and is not directly visualized on radiographs. There is a peribursal fat plane between the rotator cuff tendons and the deltoid muscle; however, obliteration of the peribursal fat stripe is not a specific indicator of shoulder pathology and may be seen in normal subjects [42]. US Shoulder US has been found to have a high accuracy in assessing rotator cuff disease [38,45], including the subscapularis tendon [46]. Meta-analyses have found a sensitivity of US ranging from 85% to 95% and a specificity ranging from 72% to 92%, which is similar to noncontrast MRI and slightly lower than MR arthrography [24,47]. Fatty infiltration within the rotator cuff muscles can be adequately demonstrated with US [48]. US may; however, be less accurate than MRI in measuring tear size and the degree of retraction in larger tears [49]. US allows excellent evaluation of the bursae situated about the shoulder, particularly the subacromial subdeltoid bursa [50]. Color flow imaging can demonstrate hyperemia in cases of bursitis with a significant inflammatory component [51]. Variant 3: Chronic shoulder pain. Radiographs demonstrate calcific tendinopathy or calcific bursitis. Next imaging study.

Chronic Shoulder Pain PCAs. Radiography Shoulder Additional Views The rotator cuff tendons cannot be directly assessed radiographically, regardless of the view. Secondary findings of rotator cuff tear such as a high-riding humeral head or changes at the greater tuberosity can be seen on standard radiographic views. There have been several reports assessing special views for the evaluation of potential impingement from the anterior acromion. Outlet views can be used to determine acromial shape and have been shown to be more accurate than a single-slice MRI [43]. The Rockwood and cassette tilt views are angled frontal projections that can be used to detect anterior acromial osteophytes [44]. The subacromial subdeltoid bursa is a soft- tissue potential space and is not directly visualized on radiographs. There is a peribursal fat plane between the rotator cuff tendons and the deltoid muscle; however, obliteration of the peribursal fat stripe is not a specific indicator of shoulder pathology and may be seen in normal subjects [42]. US Shoulder US has been found to have a high accuracy in assessing rotator cuff disease [38,45], including the subscapularis tendon [46]. Meta-analyses have found a sensitivity of US ranging from 85% to 95% and a specificity ranging from 72% to 92%, which is similar to noncontrast MRI and slightly lower than MR arthrography [24,47]. Fatty infiltration within the rotator cuff muscles can be adequately demonstrated with US [48]. US may; however, be less accurate than MRI in measuring tear size and the degree of retraction in larger tears [49]. US allows excellent evaluation of the bursae situated about the shoulder, particularly the subacromial subdeltoid bursa [50]. Color flow imaging can demonstrate hyperemia in cases of bursitis with a significant inflammatory component [51]. Variant 3: Chronic shoulder pain. Radiographs demonstrate calcific tendinopathy or calcific bursitis. Next imaging study.

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acrac_3101482_7

Chronic Shoulder Pain PCAs

Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinosis or calcific bursitis. Cases with intraosseous extension of calcium hydroxyapatite can potentially demonstrate increased radionuclide uptake due to bony inflammatory change, which can potentially be confused with a neoplastic process and result in diagnostic confusion. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Hyperdense intratendinous calcium may resemble intratendinous contrast from a partial thickness articular-sided rotator cuff tear, which could potentially result in diagnostic confusion. The role of CT arthrography is limited to cases in which there is concern Chronic Shoulder Pain for a concomitant rotator cuff tear and, even in this situation, may be lacking in utility in cases of partial thickness interstitial or bursal surface tear [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without IV Contrast Calcific hydroxyapatite deposition in the rotator cuff tendons is easily visualized by CT; however, the diagnosis of calcium hydroxyapatite is typically able to be made on radiographs alone.

Chronic Shoulder Pain PCAs. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinosis or calcific bursitis. Cases with intraosseous extension of calcium hydroxyapatite can potentially demonstrate increased radionuclide uptake due to bony inflammatory change, which can potentially be confused with a neoplastic process and result in diagnostic confusion. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Hyperdense intratendinous calcium may resemble intratendinous contrast from a partial thickness articular-sided rotator cuff tear, which could potentially result in diagnostic confusion. The role of CT arthrography is limited to cases in which there is concern Chronic Shoulder Pain for a concomitant rotator cuff tear and, even in this situation, may be lacking in utility in cases of partial thickness interstitial or bursal surface tear [18]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. CT Shoulder Without IV Contrast Calcific hydroxyapatite deposition in the rotator cuff tendons is easily visualized by CT; however, the diagnosis of calcium hydroxyapatite is typically able to be made on radiographs alone.

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acrac_3101482_8

Chronic Shoulder Pain PCAs

CT can be helpful in evaluating osseous involvement [52] and is the most accurate modality in evaluating the consistency of the deposit, which may be helpful when planning intervention [53] but is not routinely obtained. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Areas of calcium hydroxyapatite deposition in tendon, bursa, or bone can result in increased FDG uptake, which can potentially be confused with a neoplastic process and result in diagnostic confusion. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures If calcium hydroxyapatite is seen on radiographs, calcium hydroxyapatite lavage with imaging guidance can be performed both for both therapeutic and diagnostic purposes. US or, less commonly, fluoroscopy can be used for guidance. US-guided calcium lavage has been shown to be a highly effective percutaneous treatment in patients with suspected calcific tendinitis [54-62]. Outcomes are similar whether the procedure is performed with the 1 or 2 needle technique [63]. Injection of corticosteroid into the subacromial subdeltoid bursa as part of the barbotage procedure has been shown to have significant impact on pain and function 3 months after the procedure [64,65]. The degree of calcium removal does not necessarily correlate with pain improvement from the procedure [66]. Lavage may be less effective at providing pain relief for patients with intraosseous migration of calcium hydroxyapatite [67]. Given the high efficacy of calcium hydroxyapatite lavage in the rotator cuff, if patient symptoms do not resolve following calcium hydroxyapatite lavage, then other diagnostic entities for shoulder pain should be considered and further imaging evaluation can be performed subsequently.

Chronic Shoulder Pain PCAs. CT can be helpful in evaluating osseous involvement [52] and is the most accurate modality in evaluating the consistency of the deposit, which may be helpful when planning intervention [53] but is not routinely obtained. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. Areas of calcium hydroxyapatite deposition in tendon, bursa, or bone can result in increased FDG uptake, which can potentially be confused with a neoplastic process and result in diagnostic confusion. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures If calcium hydroxyapatite is seen on radiographs, calcium hydroxyapatite lavage with imaging guidance can be performed both for both therapeutic and diagnostic purposes. US or, less commonly, fluoroscopy can be used for guidance. US-guided calcium lavage has been shown to be a highly effective percutaneous treatment in patients with suspected calcific tendinitis [54-62]. Outcomes are similar whether the procedure is performed with the 1 or 2 needle technique [63]. Injection of corticosteroid into the subacromial subdeltoid bursa as part of the barbotage procedure has been shown to have significant impact on pain and function 3 months after the procedure [64,65]. The degree of calcium removal does not necessarily correlate with pain improvement from the procedure [66]. Lavage may be less effective at providing pain relief for patients with intraosseous migration of calcium hydroxyapatite [67]. Given the high efficacy of calcium hydroxyapatite lavage in the rotator cuff, if patient symptoms do not resolve following calcium hydroxyapatite lavage, then other diagnostic entities for shoulder pain should be considered and further imaging evaluation can be performed subsequently.

3101482

acrac_3101482_9

Chronic Shoulder Pain PCAs

MR Arthrography Shoulder Calcium hydroxyapatite may be difficult to visualize on MRI given the lack of contrast between hypointense calcium and an adjacent normal tendon. However, MR arthrography can be used to identify a concomitant rotator cuff tear. In the setting of calcific tendonitis, 93% of rotator cuff tears are partial thickness [68]. Given the improved ability of MR arthrography to detect partial thickness articular-surface tears of the rotator cuff compared to conventional shoulder MRI [24-26], there may be an advantage to performing MR arthrography in patients with calcific tendinopathy [69]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. MRI Shoulder Without IV Contrast The signal void of calcium hydroxyapatite deposition can be difficult to distinguish from the hypointense signal in normal rotator cuff tendon, thus making identification of calcific tendonitis by MRI alone difficult in some cases. However, MRI can be used in calcific tendonitis cases to evaluate the extent of adjacent soft-tissue and bone abnormalities as well as exclude other causes of shoulder pain. Patients with calcific tendonitis on radiographs have up to a 56% incidence of concomitant rotator cuff tear seen on MRI [68]. Intraosseous migration of calcium hydroxyapatite can produce extensive marrow edema, which can be confused with a neoplastic process [52,70]. Radiography Shoulder Additional Views Calcium hydroxyapatite deposition in tendon or bursa is typically well seen on conventional radiographic projections, without a need for specialized additional views. Chronic Shoulder Pain US Shoulder US is reported to be 98% sensitive and 94% specific for calcium hydroxyapatite in the rotator cuff tendons [71], although identification may be challenging if the area of calcium deposition is small.

Chronic Shoulder Pain PCAs. MR Arthrography Shoulder Calcium hydroxyapatite may be difficult to visualize on MRI given the lack of contrast between hypointense calcium and an adjacent normal tendon. However, MR arthrography can be used to identify a concomitant rotator cuff tear. In the setting of calcific tendonitis, 93% of rotator cuff tears are partial thickness [68]. Given the improved ability of MR arthrography to detect partial thickness articular-surface tears of the rotator cuff compared to conventional shoulder MRI [24-26], there may be an advantage to performing MR arthrography in patients with calcific tendinopathy [69]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when radiographs demonstrate calcific tendinopathy or calcific bursitis. MRI Shoulder Without IV Contrast The signal void of calcium hydroxyapatite deposition can be difficult to distinguish from the hypointense signal in normal rotator cuff tendon, thus making identification of calcific tendonitis by MRI alone difficult in some cases. However, MRI can be used in calcific tendonitis cases to evaluate the extent of adjacent soft-tissue and bone abnormalities as well as exclude other causes of shoulder pain. Patients with calcific tendonitis on radiographs have up to a 56% incidence of concomitant rotator cuff tear seen on MRI [68]. Intraosseous migration of calcium hydroxyapatite can produce extensive marrow edema, which can be confused with a neoplastic process [52,70]. Radiography Shoulder Additional Views Calcium hydroxyapatite deposition in tendon or bursa is typically well seen on conventional radiographic projections, without a need for specialized additional views. Chronic Shoulder Pain US Shoulder US is reported to be 98% sensitive and 94% specific for calcium hydroxyapatite in the rotator cuff tendons [71], although identification may be challenging if the area of calcium deposition is small.

3101482

acrac_3101482_10

Chronic Shoulder Pain PCAs

At times US may have difficulty distinguishing calcific deposits from heterotopic ossification because both can result in dense shadowing at US. US can be used if there is concern for concomitant rotator cuff tendon tear and may be a better modality than MRI in this situation given the difficulty of distinguishing calcium from normal tendon at MRI. Variant 4: Chronic shoulder pain. Suspect labral pathology or shoulder instability. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Arthrography Shoulder CT arthrograms have been shown to be an accurate modality in the assessment of shoulder instability because of its depiction of osseous, cartilaginous, and labroligamentous injuries [18,72]. Labral evaluation in the postoperative setting may be better with CT arthrography than MRI in patients with metallic suture anchors [73] and has been used to evaluate for healing after superior labrum anterior-to-posterior (SLAP) repair [74]. Dual-energy CT arthrography has a similar diagnostic performance as MR arthrography [75]. Although CT arthrography aids in the evaluation of underlying soft tissues, the injected contrast may limit evaluation of the underlying osseous structures, and cortical fragments in the injected contrast solution often have a similar attenuation to cortical bone [76]. Other limitations include the need for an invasive arthrography procedure and poor assessment of bone marrow edema [72]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected.

Chronic Shoulder Pain PCAs. At times US may have difficulty distinguishing calcific deposits from heterotopic ossification because both can result in dense shadowing at US. US can be used if there is concern for concomitant rotator cuff tendon tear and may be a better modality than MRI in this situation given the difficulty of distinguishing calcium from normal tendon at MRI. Variant 4: Chronic shoulder pain. Suspect labral pathology or shoulder instability. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Arthrography Shoulder CT arthrograms have been shown to be an accurate modality in the assessment of shoulder instability because of its depiction of osseous, cartilaginous, and labroligamentous injuries [18,72]. Labral evaluation in the postoperative setting may be better with CT arthrography than MRI in patients with metallic suture anchors [73] and has been used to evaluate for healing after superior labrum anterior-to-posterior (SLAP) repair [74]. Dual-energy CT arthrography has a similar diagnostic performance as MR arthrography [75]. Although CT arthrography aids in the evaluation of underlying soft tissues, the injected contrast may limit evaluation of the underlying osseous structures, and cortical fragments in the injected contrast solution often have a similar attenuation to cortical bone [76]. Other limitations include the need for an invasive arthrography procedure and poor assessment of bone marrow edema [72]. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected.

3101482

acrac_3101482_11

Chronic Shoulder Pain PCAs

CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Shoulder Without IV Contrast CT is helpful for assessing bony glenoid deficiency as well as the size of a Hill-Sachs deformity when surgery is a consideration but is not effective at evaluating the labrum. CT is often preferable to MRI when evaluating for small fracture fragments of the glenoid rim and assessing bone stock in patients with recurrent dislocation [77-79]. Three- dimensional reconstructions can be used to quantify osseous defect width and glenoid surface area [80,81]. CT can also be used to measure the size of a Hill-Sachs defect [82,83], which has become more important with the development of the glenoid track concept for determining instability [84,85]. In the postoperative setting, CT can be used to evaluate integration of bone graft from a coracoid transfer with the underlying glenoid [86,87]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Patients with labral tears have been found to have no significant decrease in pain with glenohumeral injection relative to other patients, and, in fact, patients with labral tears may have less pain relief than those with an intact labrum [23]. Thus, corticosteroid injection does not have a significant diagnostic benefit in distinguishing patients with labral tears from other pathology. Chronic Shoulder Pain accuracy for a labral tear as those performed with dilute gadolinium [30,31].

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. CT Shoulder Without IV Contrast CT is helpful for assessing bony glenoid deficiency as well as the size of a Hill-Sachs deformity when surgery is a consideration but is not effective at evaluating the labrum. CT is often preferable to MRI when evaluating for small fracture fragments of the glenoid rim and assessing bone stock in patients with recurrent dislocation [77-79]. Three- dimensional reconstructions can be used to quantify osseous defect width and glenoid surface area [80,81]. CT can also be used to measure the size of a Hill-Sachs defect [82,83], which has become more important with the development of the glenoid track concept for determining instability [84,85]. In the postoperative setting, CT can be used to evaluate integration of bone graft from a coracoid transfer with the underlying glenoid [86,87]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when labral pathology or shoulder instability is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Patients with labral tears have been found to have no significant decrease in pain with glenohumeral injection relative to other patients, and, in fact, patients with labral tears may have less pain relief than those with an intact labrum [23]. Thus, corticosteroid injection does not have a significant diagnostic benefit in distinguishing patients with labral tears from other pathology. Chronic Shoulder Pain accuracy for a labral tear as those performed with dilute gadolinium [30,31].

3101482

acrac_3101482_12

Chronic Shoulder Pain PCAs

Although diagnosing recurrent labral tears after prior labral repair is challenging, MR arthrography is particularly helpful in this scenario in which discrete fluid or gadolinium signal within or underlying the labrum, absent labrum, and paralabral cyst are all highly suggestive of recurrent tear [94], with a greater sensitivity than seen with conventional MRI [73]. MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34]. Indirect arthrography has been found to have a sensitivity of 74% and a specificity of 67% for SLAP tear, which is lower than for direct MR arthrography [89]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast Conventional MRI with 3T imaging is highly accurate for the detection of a labral tear, with a sensitivity of 83% and a specificity of 99% to 100% for a labral tear [90]. MR arthrography adds additional benefit to conventional shoulder MRI because it may identify some labral tears that are not seen with conventional MRI [95]. The increased accuracy with MR arthrography should be balanced against the need for an invasive arthrogram procedure. Although evaluation of glenoid bony integrity is typically better with CT imaging, some practitioners have used ultrashort or zero echo time sequences [96-98], 3-D sequences [99], or conventional MRI sequences [100] to measure glenoid bone loss with a high concordance to CT images. Radiography Shoulder Additional Views There are several options for additional radiographic views in patients with suspected instability [1]. The West Point and Garth views can demonstrate the anterior inferior glenoid at a better advantage in patients with a suspected Bankart fracture. A Stryker notch view can sometimes demonstrate a Hill-Sachs lesion that is difficult to see on conventional projections.

Chronic Shoulder Pain PCAs. Although diagnosing recurrent labral tears after prior labral repair is challenging, MR arthrography is particularly helpful in this scenario in which discrete fluid or gadolinium signal within or underlying the labrum, absent labrum, and paralabral cyst are all highly suggestive of recurrent tear [94], with a greater sensitivity than seen with conventional MRI [73]. MRI Shoulder Without and With IV Contrast IV injection of gadolinium can be used to enhance the highly vascular synovium producing an indirect arthrogram effect [34]. Indirect arthrography has been found to have a sensitivity of 74% and a specificity of 67% for SLAP tear, which is lower than for direct MR arthrography [89]. Although the accuracy of indirect MR arthrography has been described in the literature, it is not commonly used in clinical practice. MRI Shoulder Without IV Contrast Conventional MRI with 3T imaging is highly accurate for the detection of a labral tear, with a sensitivity of 83% and a specificity of 99% to 100% for a labral tear [90]. MR arthrography adds additional benefit to conventional shoulder MRI because it may identify some labral tears that are not seen with conventional MRI [95]. The increased accuracy with MR arthrography should be balanced against the need for an invasive arthrogram procedure. Although evaluation of glenoid bony integrity is typically better with CT imaging, some practitioners have used ultrashort or zero echo time sequences [96-98], 3-D sequences [99], or conventional MRI sequences [100] to measure glenoid bone loss with a high concordance to CT images. Radiography Shoulder Additional Views There are several options for additional radiographic views in patients with suspected instability [1]. The West Point and Garth views can demonstrate the anterior inferior glenoid at a better advantage in patients with a suspected Bankart fracture. A Stryker notch view can sometimes demonstrate a Hill-Sachs lesion that is difficult to see on conventional projections.

3101482

acrac_3101482_13

Chronic Shoulder Pain PCAs

Although these additional projections are used by some practitioners, they do not usually alleviate the need for advanced imaging. US Shoulder The posterior labrum can be reliably visualized with US, with posterior labral tears potentially visualized particularly if the joint is distended [101]. However, US is of limited benefit in assessing the anterior labroligamentous complex, superior labrum, articular surface, and subchondral bone. Variant 5: Chronic shoulder pain. Suspect adhesive capsulitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh Increased PET uptake in the rotator interval and inferior joint capsule is moderately associated with adhesive capsulitis [102-104]. However, this is generally an incidental finding on PET examinations performed for other reasons, and PET/CT is not typically performed specifically for this indication. Chronic Shoulder Pain

Chronic Shoulder Pain PCAs. Although these additional projections are used by some practitioners, they do not usually alleviate the need for advanced imaging. US Shoulder The posterior labrum can be reliably visualized with US, with posterior labral tears potentially visualized particularly if the joint is distended [101]. However, US is of limited benefit in assessing the anterior labroligamentous complex, superior labrum, articular surface, and subchondral bone. Variant 5: Chronic shoulder pain. Suspect adhesive capsulitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Arthrography Shoulder There is insufficient evidence to support the use of CT arthrography shoulder in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh Increased PET uptake in the rotator interval and inferior joint capsule is moderately associated with adhesive capsulitis [102-104]. However, this is generally an incidental finding on PET examinations performed for other reasons, and PET/CT is not typically performed specifically for this indication. Chronic Shoulder Pain

3101482

acrac_3101482_14

Chronic Shoulder Pain PCAs

Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the glenohumeral joint for adhesive capsulitis can be performed with either fluoroscopy or US guidance. Image-guided corticosteroid injection has been shown to have a significant reduction in pain and an improvement in the range of motion for patients with adhesive capsulitis [105,106]. Use of US guidance for glenohumeral corticosteroid injection may be more accurate and produce a greater improvement in pain and functional scores relative to blind injection [107]. Patients with adhesive capsulitis have been found to be the only group with a statistically better outcome after glenohumeral joint injection than other patients; thus a positive response to a glenohumeral injection can be suggestive of the presence of adhesive capsulitis in the appropriate clinical context [23]. Fluoroscopic injection can also demonstrate diagnostic findings suggestive of adhesive capsulitis including joint space capacity <10 mL, diminished axillary recess, and irregularity of the capsular margin [108]. MR Arthrography Shoulder Mengiardi et al [109] reported that thickening of the coracohumeral ligament (specificity 95%, sensitivity 59%), thickening of the joint capsule (specificity 86%, sensitivity 64%), and obliteration of the subcoracoid triangle (specificity 100%, sensitivity 32%) are characteristic MR arthrography findings in adhesive capsulitis. However, fluid within the rotator interval or along the axillary recess due to the arthrogram injection itself can serve as a limitation to detecting findings of adhesive capsulitis on MRI arthrography. MRI Shoulder Without and With IV Contrast Contrast-enhanced MRI can increase the conspicuity of axillary recess capsular thickening [110] and rotator interval soft-tissue thickening [111], although there are conflicting data on the relationship of this capsular enhancement with patient symptoms [112].

Chronic Shoulder Pain PCAs. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the glenohumeral joint for adhesive capsulitis can be performed with either fluoroscopy or US guidance. Image-guided corticosteroid injection has been shown to have a significant reduction in pain and an improvement in the range of motion for patients with adhesive capsulitis [105,106]. Use of US guidance for glenohumeral corticosteroid injection may be more accurate and produce a greater improvement in pain and functional scores relative to blind injection [107]. Patients with adhesive capsulitis have been found to be the only group with a statistically better outcome after glenohumeral joint injection than other patients; thus a positive response to a glenohumeral injection can be suggestive of the presence of adhesive capsulitis in the appropriate clinical context [23]. Fluoroscopic injection can also demonstrate diagnostic findings suggestive of adhesive capsulitis including joint space capacity <10 mL, diminished axillary recess, and irregularity of the capsular margin [108]. MR Arthrography Shoulder Mengiardi et al [109] reported that thickening of the coracohumeral ligament (specificity 95%, sensitivity 59%), thickening of the joint capsule (specificity 86%, sensitivity 64%), and obliteration of the subcoracoid triangle (specificity 100%, sensitivity 32%) are characteristic MR arthrography findings in adhesive capsulitis. However, fluid within the rotator interval or along the axillary recess due to the arthrogram injection itself can serve as a limitation to detecting findings of adhesive capsulitis on MRI arthrography. MRI Shoulder Without and With IV Contrast Contrast-enhanced MRI can increase the conspicuity of axillary recess capsular thickening [110] and rotator interval soft-tissue thickening [111], although there are conflicting data on the relationship of this capsular enhancement with patient symptoms [112].

3101482

acrac_3101482_15

Chronic Shoulder Pain PCAs

MRI Shoulder Without IV Contrast Zhao et al [113] showed that coracohumeral ligament thickening, anterior capsule thickening, and obliteration of the subcoracoid fat are the most characteristic findings of adhesive capsulitis on conventional MRI. Chi et al [114] found a sensitivity of 77% and a specificity of 53% for adhesive capsulitis with only coracohumeral ligament thickening on noncontrast MRI, with a lower sensitivity (23%) but a higher specificity (87%) in patients who had all 3 findings of adhesive capsulitis, including coracohumeral ligament thickening, rotator interval infiltration, and axillary recess thickening. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. US Shoulder US in the setting of potential adhesive capsulitis is often used to exclude rotator cuff tear. Although there are several US findings that can be seen in patients with adhesive capsulitis, US is not typically performed specifically for this indication. Thickening of the coracohumeral ligament, increased rotator interval soft tissue, and decreased external rotation on dynamic US are all highly sensitive and specific findings for adhesive capsulitis [115]. Thickening of the axillary recess capsule can be accurately measured with US and is associated with adhesive capsulitis [116]. Hyperemia with Doppler imaging, particularly with microflow imaging, can also be seen in the subcoracoid fat triangle in patients with adhesive capsulitis [117]. One study found that findings of adhesive capsulitis on US were correlated with clinical assessment, whereas findings on MRI were not [108]. Variant 6: Chronic shoulder pain. Suspect biceps tendon abnormality. Initial radiographs normal or inconclusive. Next imaging study.

Chronic Shoulder Pain PCAs. MRI Shoulder Without IV Contrast Zhao et al [113] showed that coracohumeral ligament thickening, anterior capsule thickening, and obliteration of the subcoracoid fat are the most characteristic findings of adhesive capsulitis on conventional MRI. Chi et al [114] found a sensitivity of 77% and a specificity of 53% for adhesive capsulitis with only coracohumeral ligament thickening on noncontrast MRI, with a lower sensitivity (23%) but a higher specificity (87%) in patients who had all 3 findings of adhesive capsulitis, including coracohumeral ligament thickening, rotator interval infiltration, and axillary recess thickening. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when adhesive capsulitis is suspected. US Shoulder US in the setting of potential adhesive capsulitis is often used to exclude rotator cuff tear. Although there are several US findings that can be seen in patients with adhesive capsulitis, US is not typically performed specifically for this indication. Thickening of the coracohumeral ligament, increased rotator interval soft tissue, and decreased external rotation on dynamic US are all highly sensitive and specific findings for adhesive capsulitis [115]. Thickening of the axillary recess capsule can be accurately measured with US and is associated with adhesive capsulitis [116]. Hyperemia with Doppler imaging, particularly with microflow imaging, can also be seen in the subcoracoid fat triangle in patients with adhesive capsulitis [117]. One study found that findings of adhesive capsulitis on US were correlated with clinical assessment, whereas findings on MRI were not [108]. Variant 6: Chronic shoulder pain. Suspect biceps tendon abnormality. Initial radiographs normal or inconclusive. Next imaging study.

3101482

acrac_3101482_16

Chronic Shoulder Pain PCAs

Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Arthrography Shoulder Reports on the accuracy of CT arthrography for biceps tendinopathy are variable. Teixeira et al [118] reported a sensitivity of 74% to 79% and a specificity of 93% to 95% for tendinopathy as well as 100% sensitivity and 93% specificity for complete biceps ruptures. However, Rol et al [119] reported a correlation of only 45% to 65% with subsequent arthroscopy in a study consisting mostly of patients who underwent CT arthrography. CT arthrography diagnosis of biceps tendinopathy is primarily based off the change in tendon caliber. Chronic Shoulder Pain CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without IV Contrast There is limited literature regarding the use of noncontrast CT to specifically evaluate the biceps tendon. In a small study, pooled sensitivity and specificity for proximal biceps lesions including degeneration, tendon subluxation, and tendon tear using CT were shown to be 31% and 95%, respectively [120]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the biceps tendon sheath using US guidance may be useful in patients with biceps pain for both diagnostic and therapeutic purposes [22].

Chronic Shoulder Pain PCAs. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Arthrography Shoulder Reports on the accuracy of CT arthrography for biceps tendinopathy are variable. Teixeira et al [118] reported a sensitivity of 74% to 79% and a specificity of 93% to 95% for tendinopathy as well as 100% sensitivity and 93% specificity for complete biceps ruptures. However, Rol et al [119] reported a correlation of only 45% to 65% with subsequent arthroscopy in a study consisting mostly of patients who underwent CT arthrography. CT arthrography diagnosis of biceps tendinopathy is primarily based off the change in tendon caliber. Chronic Shoulder Pain CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. CT Shoulder Without IV Contrast There is limited literature regarding the use of noncontrast CT to specifically evaluate the biceps tendon. In a small study, pooled sensitivity and specificity for proximal biceps lesions including degeneration, tendon subluxation, and tendon tear using CT were shown to be 31% and 95%, respectively [120]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided injection of the biceps tendon sheath using US guidance may be useful in patients with biceps pain for both diagnostic and therapeutic purposes [22].

3101482

acrac_3101482_17

Chronic Shoulder Pain PCAs

Although either fluoroscopy or US can be used as imaging guidance for biceps tendon injection, US guidance is more accurate [121]. US is more accurate in injection location placement compared with blind injections with a lower risk of intratendinous injection [122,123]. Many patients with sonographically normal biceps tendons may obtain pain relief with US-guided injection, suggesting that injection response may diagnostically identify patients with biceps pathology that is not seen by US [124]. MR Arthrography Shoulder MR arthrography may improve the accuracy of MRI in the detection of long head of the bicep tears, although results are mixed. Zanetti et al [125] found MR arthrography to be sensitive and moderately specific in the diagnosis of long head of the biceps tendon disorders with a sensitivity of 92% and a specificity of 56%. However, Loock et al [126] found a lower sensitivity and specificity for MR arthrography detection of biceps abnormalities, with only a 49% sensitivity for tendinopathy. Accuracy for middle-aged patients may be lower [127]. MR arthrography is moderately accurate at assessing for biceps tendon subluxation, with a sensitivity of 61% to 87% and a specificity of 83% to 92% [128]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. MRI Shoulder Without IV Contrast Standard noncontrast MRI is limited in detecting bicep abnormalities, including tendinopathy or tearing of the long head of the biceps. Studies have shown MRI to both under- and overdiagnose intra-articular biceps pathology [129- 131], with sensitivities and specificities of 28% and 84% (partial tear) and 56% and 98% (complete), respectively [130].

Chronic Shoulder Pain PCAs. Although either fluoroscopy or US can be used as imaging guidance for biceps tendon injection, US guidance is more accurate [121]. US is more accurate in injection location placement compared with blind injections with a lower risk of intratendinous injection [122,123]. Many patients with sonographically normal biceps tendons may obtain pain relief with US-guided injection, suggesting that injection response may diagnostically identify patients with biceps pathology that is not seen by US [124]. MR Arthrography Shoulder MR arthrography may improve the accuracy of MRI in the detection of long head of the bicep tears, although results are mixed. Zanetti et al [125] found MR arthrography to be sensitive and moderately specific in the diagnosis of long head of the biceps tendon disorders with a sensitivity of 92% and a specificity of 56%. However, Loock et al [126] found a lower sensitivity and specificity for MR arthrography detection of biceps abnormalities, with only a 49% sensitivity for tendinopathy. Accuracy for middle-aged patients may be lower [127]. MR arthrography is moderately accurate at assessing for biceps tendon subluxation, with a sensitivity of 61% to 87% and a specificity of 83% to 92% [128]. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when biceps tendon abnormality is suspected. MRI Shoulder Without IV Contrast Standard noncontrast MRI is limited in detecting bicep abnormalities, including tendinopathy or tearing of the long head of the biceps. Studies have shown MRI to both under- and overdiagnose intra-articular biceps pathology [129- 131], with sensitivities and specificities of 28% and 84% (partial tear) and 56% and 98% (complete), respectively [130].

3101482

acrac_3101482_18

Chronic Shoulder Pain PCAs

Using diagnostic criteria of having 2 or more signs of biceps tendinopathy (contour irregularity, diameter change, or abnormal signal) has a sensitivity of 78% and a specificity of 94% [132]. It has been reported that normal appearing tendons on MRI frequently have histopathologic findings of tendinopathy [133,134]. Biceps tendon subluxation can be diagnosed by displacement of the biceps tendon over the lesser tuberosity [135] and is highly associated with tearing of the subscapularis tendon [136]. MRI has a greater specificity for biceps tendon abnormality if there is a coexisting rotator cuff tear [129,137]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when a biceps tendon abnormality is suspected. US Shoulder Apart from the biceps anchor, the intra-articular and extra-articular portions of the biceps tendon are well seen on routine US imaging. Tendinopathy, tears and rupture, tenosynovitis, subluxation, and frank dislocation are readily assessed [138,139]. Provocative maneuvers may be helpful while observing in real time to assess the degree of subluxation. Chronic Shoulder Pain Variant 7: Chronic shoulder pain. Initial radiographs demonstrate osteoarthritis. Next imaging study. The presence of glenohumeral osteoarthritis on initial radiographs does not typically require additional imaging unless additional pathology is suspected, such as a rotator cuff tear or surgery is a consideration. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Arthrography Shoulder CT arthrography can be helpful in the preoperative planning of total shoulder arthroplasty in patients with severe glenohumeral arthritis.

Chronic Shoulder Pain PCAs. Using diagnostic criteria of having 2 or more signs of biceps tendinopathy (contour irregularity, diameter change, or abnormal signal) has a sensitivity of 78% and a specificity of 94% [132]. It has been reported that normal appearing tendons on MRI frequently have histopathologic findings of tendinopathy [133,134]. Biceps tendon subluxation can be diagnosed by displacement of the biceps tendon over the lesser tuberosity [135] and is highly associated with tearing of the subscapularis tendon [136]. MRI has a greater specificity for biceps tendon abnormality if there is a coexisting rotator cuff tear [129,137]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain when a biceps tendon abnormality is suspected. US Shoulder Apart from the biceps anchor, the intra-articular and extra-articular portions of the biceps tendon are well seen on routine US imaging. Tendinopathy, tears and rupture, tenosynovitis, subluxation, and frank dislocation are readily assessed [138,139]. Provocative maneuvers may be helpful while observing in real time to assess the degree of subluxation. Chronic Shoulder Pain Variant 7: Chronic shoulder pain. Initial radiographs demonstrate osteoarthritis. Next imaging study. The presence of glenohumeral osteoarthritis on initial radiographs does not typically require additional imaging unless additional pathology is suspected, such as a rotator cuff tear or surgery is a consideration. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Arthrography Shoulder CT arthrography can be helpful in the preoperative planning of total shoulder arthroplasty in patients with severe glenohumeral arthritis.

3101482

acrac_3101482_19

Chronic Shoulder Pain PCAs

CT arthrography provides excellent imaging of osseous detail allowing for characterization of glenoid morphology, version, and bone loss. Unlike nonarthrogram CT, CT arthrography allows for adequate characterization of a rotator cuff tear [16,17], which may alter the chosen arthroplasty type. Arthrogram contrast also outlines the articular cartilage surface, demonstrating areas of cartilage loss, which cannot be directly visualized with conventional CT. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without IV Contrast CT can be helpful in evaluating osseous morphology in cases in which arthroplasty surgery is under consideration for treatment of severe glenohumeral arthritis. CT images are commonly obtained to classify the morphology of the glenoid according to the Walch classification system [140]. CT measurements of glenoid version, glenoid bone loss, and humeral head subluxation demonstrate high interrater reliability [141]. CT can potentially demonstrate rotator cuff muscle fatty infiltration, which is often associated with rotator cuff tears; however, overall sensitivity for full thickness rotator cuff tears is only 20% for noncontrast CT [19]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis.

Chronic Shoulder Pain PCAs. CT arthrography provides excellent imaging of osseous detail allowing for characterization of glenoid morphology, version, and bone loss. Unlike nonarthrogram CT, CT arthrography allows for adequate characterization of a rotator cuff tear [16,17], which may alter the chosen arthroplasty type. Arthrogram contrast also outlines the articular cartilage surface, demonstrating areas of cartilage loss, which cannot be directly visualized with conventional CT. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. CT Shoulder Without IV Contrast CT can be helpful in evaluating osseous morphology in cases in which arthroplasty surgery is under consideration for treatment of severe glenohumeral arthritis. CT images are commonly obtained to classify the morphology of the glenoid according to the Walch classification system [140]. CT measurements of glenoid version, glenoid bone loss, and humeral head subluxation demonstrate high interrater reliability [141]. CT can potentially demonstrate rotator cuff muscle fatty infiltration, which is often associated with rotator cuff tears; however, overall sensitivity for full thickness rotator cuff tears is only 20% for noncontrast CT [19]. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis.

3101482

acrac_3101482_20

Chronic Shoulder Pain PCAs

Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Intra-articular corticosteroid injection using either fluoroscopy or US guidance is often used in the conservative management of glenohumeral arthritis [122] and may be performed in some situations before advanced imaging is obtained. The diagnostic utility of glenohumeral corticosteroid injection for confirming osteoarthritis as a source of pain is limited, because patients with osteoarthritis have a similar degree of pain improvement (74% rate of clinically relevant improvement at 1 month) as patients with other underlying causes of shoulder pain [23]. MR Arthrography Shoulder The role of MR arthrography relative to conventional shoulder MRI in the setting of osteoarthritis has not been specifically studied. However, MR arthrography may have use in characterizing the degree of chondral loss, the presence of a full thickness rotator cuff tear, and characterizing glenoid morphology. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. MRI Shoulder Without IV Contrast MRI can be used to detect the degree of glenohumeral chondral loss, although the diagnosis of arthritis is generally easily made with conventional radiographs [142]. MRI can demonstrate the presence of a partial or full thickness rotator cuff tear, which is frequently associated with osteoarthritis. Although CT is most frequently used for evaluating glenoid morphology, glenoid version measured by MRI is generally similar to that measured with CT [143]; however, MRI may be less accurate than CT at identifying the Walch classification of glenoid morphology [144]. Chronic Shoulder Pain Radiography Shoulder Additional Views Glenohumeral osteoarthritis is typically well visualized on conventional radiographic views, without the need for special views.

Chronic Shoulder Pain PCAs. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Intra-articular corticosteroid injection using either fluoroscopy or US guidance is often used in the conservative management of glenohumeral arthritis [122] and may be performed in some situations before advanced imaging is obtained. The diagnostic utility of glenohumeral corticosteroid injection for confirming osteoarthritis as a source of pain is limited, because patients with osteoarthritis have a similar degree of pain improvement (74% rate of clinically relevant improvement at 1 month) as patients with other underlying causes of shoulder pain [23]. MR Arthrography Shoulder The role of MR arthrography relative to conventional shoulder MRI in the setting of osteoarthritis has not been specifically studied. However, MR arthrography may have use in characterizing the degree of chondral loss, the presence of a full thickness rotator cuff tear, and characterizing glenoid morphology. MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain when initial radiographs demonstrate osteoarthritis. MRI Shoulder Without IV Contrast MRI can be used to detect the degree of glenohumeral chondral loss, although the diagnosis of arthritis is generally easily made with conventional radiographs [142]. MRI can demonstrate the presence of a partial or full thickness rotator cuff tear, which is frequently associated with osteoarthritis. Although CT is most frequently used for evaluating glenoid morphology, glenoid version measured by MRI is generally similar to that measured with CT [143]; however, MRI may be less accurate than CT at identifying the Walch classification of glenoid morphology [144]. Chronic Shoulder Pain Radiography Shoulder Additional Views Glenohumeral osteoarthritis is typically well visualized on conventional radiographic views, without the need for special views.

3101482

acrac_3101482_21

Chronic Shoulder Pain PCAs

A standard axillary view can demonstrate posterior subluxation of the humeral head and abnormal glenoid morphology in patients with severe osteoarthritis [145-147]. A measurement of the critical shoulder angle can be drawn on routine AP radiographs by measuring the angle between a line along the glenoid surface and a line from the inferior glenoid to the lateral acromial margin; patients with a higher measurement may be at high risk of having a full thickness rotator cuff tear [148]. US Shoulder Although secondary signs of osteoarthritis such as osteophytes, joint effusion, and intra-articular bodies can be seen with US [142], it is not typically performed for this indication. Variant 8: Chronic shoulder pain. History of prior rotator cuff repair. Suspect rotator cuff disorders or subacromial subdeltoid bursitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder As in the native shoulder, CT arthrography can be used to evaluate for rotator cuff tear after surgery. In patients with metal in the shoulder, CT arthrography can be beneficial in detecting supraspinatus tears that may be obscured by metal artifact [73]. Gadolinium contrast can potentially be drawn up into a mixture with iodinated contrast at the time of the arthrogram procedure, thus allowing for a shift from MRI to CT if artifact on MRI precludes evaluation. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.

Chronic Shoulder Pain PCAs. A standard axillary view can demonstrate posterior subluxation of the humeral head and abnormal glenoid morphology in patients with severe osteoarthritis [145-147]. A measurement of the critical shoulder angle can be drawn on routine AP radiographs by measuring the angle between a line along the glenoid surface and a line from the inferior glenoid to the lateral acromial margin; patients with a higher measurement may be at high risk of having a full thickness rotator cuff tear [148]. US Shoulder Although secondary signs of osteoarthritis such as osteophytes, joint effusion, and intra-articular bodies can be seen with US [142], it is not typically performed for this indication. Variant 8: Chronic shoulder pain. History of prior rotator cuff repair. Suspect rotator cuff disorders or subacromial subdeltoid bursitis. Initial radiographs normal or inconclusive. Next imaging study. Bone Scan Shoulder There is insufficient evidence to support the use of bone scan shoulder in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Arthrography Shoulder As in the native shoulder, CT arthrography can be used to evaluate for rotator cuff tear after surgery. In patients with metal in the shoulder, CT arthrography can be beneficial in detecting supraspinatus tears that may be obscured by metal artifact [73]. Gadolinium contrast can potentially be drawn up into a mixture with iodinated contrast at the time of the arthrogram procedure, thus allowing for a shift from MRI to CT if artifact on MRI precludes evaluation. CT Shoulder With IV Contrast There is insufficient evidence to support the use of CT shoulder with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected.

3101482

acrac_3101482_22

Chronic Shoulder Pain PCAs

CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided corticosteroid injection may be useful for therapeutic purposes in patients with recurrent pain after rotator cuff repair. US-guided injection of corticosteroid into the glenohumeral joint has been found to improve pain and range of motion in patients with prior rotator cuff repair, without increasing the risk of recurrent rotator cuff tear [149]. There is insufficient evidence to support the use of image guided injection for diagnostic purposes in evaluation for recurrent cuff tear, but it may be of use for diagnosis in patients with suspected subacromial subdeltoid bursitis. MR Arthrography Shoulder MR arthrography is useful in the evaluation of the postoperative rotator cuff. MR arthrography can improve diagnostic accuracy over conventional MRI in patients who have had prior rotator cuff repair due to joint distention and improved signal-to-noise ratio [150].

Chronic Shoulder Pain PCAs. CT Shoulder Without and With IV Contrast There is insufficient evidence to support the use of CT shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. CT Shoulder Without IV Contrast There is insufficient evidence to support the use of CT shoulder without IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. FDG-PET/CT Skull Base to Mid-Thigh There is insufficient evidence to support the use of FDG-PET/CT skull base to mid-thigh in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. Image-Guided Anesthetic +/- Corticosteroid Injection Shoulder or Surrounding Structures Image-guided corticosteroid injection may be useful for therapeutic purposes in patients with recurrent pain after rotator cuff repair. US-guided injection of corticosteroid into the glenohumeral joint has been found to improve pain and range of motion in patients with prior rotator cuff repair, without increasing the risk of recurrent rotator cuff tear [149]. There is insufficient evidence to support the use of image guided injection for diagnostic purposes in evaluation for recurrent cuff tear, but it may be of use for diagnosis in patients with suspected subacromial subdeltoid bursitis. MR Arthrography Shoulder MR arthrography is useful in the evaluation of the postoperative rotator cuff. MR arthrography can improve diagnostic accuracy over conventional MRI in patients who have had prior rotator cuff repair due to joint distention and improved signal-to-noise ratio [150].

3101482

acrac_3101482_23

Chronic Shoulder Pain PCAs

Of note, contrast within the subacromial subdeltoid bursa on routine and MR arthrogram examinations is a nonspecific finding that can potentially be seen in a nonwatertight rotator cuff repair [151]. T2 hyperintensity of the repaired rotator cuff tendon is a common postoperative finding, particularly in the first 2 years after surgery, and does not reflect adequacy of tendon healing or clinical outcome [152]. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. MRI Shoulder Without IV Contrast MRI is useful in the evaluation of the postoperative rotator cuff. The shift from metallic to bioabsorbable suture anchors tends to result in fewer cases with metal artifact implications [153]. For patients with metallic suture anchors, there are a variety of commercially available metal artifact reduction sequences, which can limit artifact. MRI can demonstrate complications with suture anchors such as osteolysis or migration [154], even if the suture anchors are nonmetallic. MRI can also demonstrate potential improvements in muscle atrophy and fatty infiltration after rotator cuff repair [155,156]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. US Shoulder An advantage of US evaluation of the postoperative shoulder is the absence of metal-induced artifact when examining the rotator cuff and adjacent soft tissues. Patients who have undergone rotator cuff repair may show discrete defects on US imaging that may persist for years with some potential for delayed healing [157].

Chronic Shoulder Pain PCAs. Of note, contrast within the subacromial subdeltoid bursa on routine and MR arthrogram examinations is a nonspecific finding that can potentially be seen in a nonwatertight rotator cuff repair [151]. T2 hyperintensity of the repaired rotator cuff tendon is a common postoperative finding, particularly in the first 2 years after surgery, and does not reflect adequacy of tendon healing or clinical outcome [152]. Chronic Shoulder Pain MRI Shoulder Without and With IV Contrast There is insufficient evidence to support the use of MRI shoulder without and with IV contrast in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when a rotator cuff disorder or subacromial subdeltoid bursitis is suspected. MRI Shoulder Without IV Contrast MRI is useful in the evaluation of the postoperative rotator cuff. The shift from metallic to bioabsorbable suture anchors tends to result in fewer cases with metal artifact implications [153]. For patients with metallic suture anchors, there are a variety of commercially available metal artifact reduction sequences, which can limit artifact. MRI can demonstrate complications with suture anchors such as osteolysis or migration [154], even if the suture anchors are nonmetallic. MRI can also demonstrate potential improvements in muscle atrophy and fatty infiltration after rotator cuff repair [155,156]. Radiography Shoulder Additional Views There is insufficient evidence to support the use of additional radiographic views in the evaluation of chronic shoulder pain with a history of prior rotator cuff repair when rotator cuff disorder or subacromial subdeltoid bursitis is suspected. US Shoulder An advantage of US evaluation of the postoperative shoulder is the absence of metal-induced artifact when examining the rotator cuff and adjacent soft tissues. Patients who have undergone rotator cuff repair may show discrete defects on US imaging that may persist for years with some potential for delayed healing [157].

3101482

acrac_3158170_0

Dialysis Fistula Malfunction

Introduction/Background Chronic kidney disease is a common disease that as of 2018 affected 14.9% of the surveyed adult United States population [1]. Chronic kidney disease can result in end stage renal disease, a condition with high morbidity and mortality that affects 725,000 patients in the United States as of 2016 [2]. End stage renal disease patients account for 7.2% of paid Medicare claims at a cost of $35.4 billion, a cost that is increasing every year [2]. In the United States, hemodialysis persists as the single most prevalent mode of renal replacement therapy. Hemodialysis care alone resulted in $28 billion in Medicare costs in 2016 [2]. A stenosis that develops secondary to neointimal hyperplasia becomes the primary precipitator of a vascular access failure. Such stenoses augment pressure within the access and decrease blood flow. If the stenosis is hemodynamically significant and left untreated, it can result in thrombosis of the access. Access thrombosis is the primary cause of loss of vascular access patency and is associated with an increase in health care expenditure and compromise of quality of life [9]. The occurrence of a stenosis is an event that recurs throughout the life of the access. While a vein-graft anastomosis in a patient with an AVG or juxta-anastomotic region in a patient with an AVF represent the sites with high propensity for stenosis formation, these lesions may occur at any point within the The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Dialysis Fistula Malfunction access system, notwithstanding central and feeding arteries.

Dialysis Fistula Malfunction. Introduction/Background Chronic kidney disease is a common disease that as of 2018 affected 14.9% of the surveyed adult United States population [1]. Chronic kidney disease can result in end stage renal disease, a condition with high morbidity and mortality that affects 725,000 patients in the United States as of 2016 [2]. End stage renal disease patients account for 7.2% of paid Medicare claims at a cost of $35.4 billion, a cost that is increasing every year [2]. In the United States, hemodialysis persists as the single most prevalent mode of renal replacement therapy. Hemodialysis care alone resulted in $28 billion in Medicare costs in 2016 [2]. A stenosis that develops secondary to neointimal hyperplasia becomes the primary precipitator of a vascular access failure. Such stenoses augment pressure within the access and decrease blood flow. If the stenosis is hemodynamically significant and left untreated, it can result in thrombosis of the access. Access thrombosis is the primary cause of loss of vascular access patency and is associated with an increase in health care expenditure and compromise of quality of life [9]. The occurrence of a stenosis is an event that recurs throughout the life of the access. While a vein-graft anastomosis in a patient with an AVG or juxta-anastomotic region in a patient with an AVF represent the sites with high propensity for stenosis formation, these lesions may occur at any point within the The American College of Radiology seeks and encourages collaboration with other organizations on the development of the ACR Appropriateness Criteria through representation of such organizations on expert panels. Participation on the expert panel does not necessarily imply endorsement of the final document by individual contributors or their respective organization. Reprint requests to: publications@acr.org Dialysis Fistula Malfunction access system, notwithstanding central and feeding arteries.

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Dialysis Fistula Malfunction

A stenotic lesion can provoke access dysfunction regardless of its site within the access circuit [9]. Arteriovenous (AV) access dysfunction includes 3 distinct classes of events, namely thrombotic flow-related complications or dysfunction, nonthrombotic flow-related complications or dysfunction, and infectious complications [5]. Thrombotic flow-related complications or dysfunction include those events exclusively related to thrombus formation that provokes a clinically important decrease in intra-access flow and in turn threatens the required access patency needed to achieve requisite hemodialysis. These include stenoses and thromboses, and routinely result in specific heralding clinical signs and symptoms. Nonthrombotic flow-related complications or dysfunction include those events that may or may not threaten the flow or patency of an access circuit, but which are related to associated clinical symptoms and signs, such as in the case of steal syndrome or AV access cannulation site aneurysms. Finally, infectious complications or dysfunction include infections that involve the vascular access whether intraluminally, extraluminally, or peri-access, including the cannulation site, and that provoke clinically significant infectious symptoms and signs [5]. To preempt adverse outcomes and identify lesions with the vascular access before they provoke complications, the KDOQI guidelines suggests that the performance of the following be considered, namely 1) monitoring, supported by physical examination. Such abnormal clinical signs and symptoms may include changes in the access thrill or bruit, prolonged bleeding after decannulation post dialysis, or arm swelling.

Dialysis Fistula Malfunction. A stenotic lesion can provoke access dysfunction regardless of its site within the access circuit [9]. Arteriovenous (AV) access dysfunction includes 3 distinct classes of events, namely thrombotic flow-related complications or dysfunction, nonthrombotic flow-related complications or dysfunction, and infectious complications [5]. Thrombotic flow-related complications or dysfunction include those events exclusively related to thrombus formation that provokes a clinically important decrease in intra-access flow and in turn threatens the required access patency needed to achieve requisite hemodialysis. These include stenoses and thromboses, and routinely result in specific heralding clinical signs and symptoms. Nonthrombotic flow-related complications or dysfunction include those events that may or may not threaten the flow or patency of an access circuit, but which are related to associated clinical symptoms and signs, such as in the case of steal syndrome or AV access cannulation site aneurysms. Finally, infectious complications or dysfunction include infections that involve the vascular access whether intraluminally, extraluminally, or peri-access, including the cannulation site, and that provoke clinically significant infectious symptoms and signs [5]. To preempt adverse outcomes and identify lesions with the vascular access before they provoke complications, the KDOQI guidelines suggests that the performance of the following be considered, namely 1) monitoring, supported by physical examination. Such abnormal clinical signs and symptoms may include changes in the access thrill or bruit, prolonged bleeding after decannulation post dialysis, or arm swelling.

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