bluuebunny/crossref_metadata_2025 huggingface dataset:
Transcranial Sonography of Brain Tumors in the Adult: An In Vitro and In Vivo Study
Authors: Meyer Karsten , Seidel Günter , Knopp Ulrich
Published: November 2009

Background. Few reports indicate the potential of transcranial sonography (TCS) in detecting human brain tumors. Methods. With an Agilent Sonos 2500 ultrasound device, the authors studied 4 brain tumor phantoms and compared the findings with magnetic resonance imaging (MRI). TCS was performed on 40 patients with intracranial tumors in a follow‐up design. Sonographic tumor volume and affection of the ventricular system were compared with MRI findings. Results. The authors found a good correlation between TCS and MRI volumetry in the in vitro study. TCS showed good intraobserver and interobserver reliability. A new volumetric formula for TCS measurement was determined. TCS detection rate of brain tumors in vivo was 40%. When the investigators were given access to radiological findings, the rate of tumor identification was 80%. Despite a sufficient acoustic window, 40% of gliomas grade II and III were not detected. One glioblastoma was not identified owing to an insufficient temporal acoustic window. Tumor volumes measured with MRI and TCS correlated well. MRI volumes exceeded TCS volumes by 41%. In the postoperative examinations (mean = 8 days postoperative, n= 15), the resection cavity was displayed as hyperechogenic. It appeared impossible to differentiate between residual tumor tissue and normal repair mechanisms or blood. In the follow‐up examination (mean = 99 days postoperative, n= 15) in 5 patients, neither MRI nor TCS showed tumor regrowth. Ten patients had residual tumors that were detected by sonography. Conclusions. The value of TCS for the diagnostics of brain tumors is at present limited. Once the tumor has been identified, sonographic results match well with those of MRI.
Does Reversal of Ischemia on Diffusion‐Weighted Imaging Reflect Higher Apparent Diffusion Coefficient Values?
Authors: Lutsep Helmi L. , Nesbit Gary M. , Berger Richard M. , Coshow William R.
Published: November 2009

This study investigated whether ischemia on diffusion‐weighted imaging (DWI) that reverses has higher apparent diffusion coefficients (ADCs). A patient treated with thrombolytics was evaluated with serial magnetic resonance imaging studies before treatment, at 3 and 14 days and at 4 weeks. A 100.01‐cm3left frontoparietal stroke on baseline DWI was only 18.11 cm3(18%) on 4‐week fluid attenuated inversion recovery. The mean ADC was 7.43 × 10−3mm2/s in the 6 regions that reversed and 7.31 × 10−3mm2/s in the 6 regions that persisted (P < .036). With thrombolytic treatment, large ischemic lesions on DWI may reverse, and these areas display higher mean ADCs.
Dural Arteriovenous Fistula Associated With Prothrombin Gene Mutation
Authors: Singh Vineeta
Published: November 2009

An association between dural arteriovenous fistula and cerebral sinus thrombosis is reported. It is clear in several cases that thrombosis precedes the development of the fistula while it is unclear that it occurs in every case. The author reports a case of a woman with sinus thrombosis and presence of prothrombin gene mutation who subsequently developed a large dural arteriovenous fistula. Various possible factors involved in the pathogenesis of a dural fistula are discussed, with emphasis on underlying thrombophilia and oral contraceptive use in this patient.
Cerebral Vasculitis: Diagnosis and Follow‐Up With Transcranial Doppler Ultrasonography
Authors: Razumovsky Alexander Y. , Wityk Robert J. , Geocadin Romergryko G. , Bhardwaj Anish , Ulatowski John A.
Published: November 2009

The authors report a patient with postpartum intracerebral hemorrhage associated with cerebral vasculitis. Cerebral circulation was assessed with transcranial Doppler (TCD) ultrasonography, magnetic resonance angiography, and conventional cerebral angiography. Initial TCD studies demonstrated bilateral patchy increased cerebral blood flow velocity (CBFV) in the anterior circulation with complete normalization during remission. This case report provides evidence that cerebral vasculitis leads to relevant CBFV changes and that the TCD technique may assist in diagnosis and follow‐up of these patients.
Screening for Intracranial Stenosis With Transcranial Doppler: The Accuracy of Mean Flow Velocity Thresholds
Authors: Felberg Robert A. , Christou Ioannis , Demchuk Andrew M. , Malkoff Marc , Alexandrov Andrei V.
Published: November 2009

Background. Patients with 50% intracranial arterial stenosis may require more intensive therapies for stroke prevention. Transcranial Doppler (TCD) is a convenient noninvasive screen for intracranial stenosis. The accuracy of different mean flow velocity (MFV) thresholds for determining the degree of stenosis remains uncertain. Methods. The authors prospectively compared the accuracy of TCD criteria and MFV thresholds to magnetic resonance, computed tomography, and digital subtraction angiography in patients with symptoms of recent or remote stroke or transient ischemic attack. Stenosis on angiography was measured as 0%, <50%, or ≥50% diameter reduction. Results. Of 136 consecutive patients, 33 (24%) had distal internal carotid artery (ICA), middle cerebral artery (MCA), posterior cerebral artery, or basilar artery stenosis on angiography (14 patients [10%] were excluded due to incomplete TCD examinations, mainly from a lack of temporal windows). TCD showed 31 true‐positive, 9 false‐positive, 2 false‐negative, and 94 true‐negative studies. For all vessels, TCD had a sensitivity of 93.9% (confidence interval [CI] = 89%‐98%), a specificity of 91.2% (CI = 87%‐96%), a positive predictive value (PPV) of 77.5%, and a negative predictive value (NPV) of 97.9%. The trade‐off in sensitivity and specificity for MCA MFV thresholds was as follows: MFV ≥80 cm/s had a sensitivity of 100%, a specificity of 96.9% (CI = 94%‐99%), a PPV of 84%, and an NPV of 100%. MFV≥100 cm/s had a sensitivity of 100%, a specificity of 97.9% (CI = 96%‐99%), a PPV of 88.8%, and an NPV of 94.9%. MFV≥120 cm/s had a sensitivity of 68.7% (CI = 61%‐78%), a specificity of 100%, a PPV of 100%, and an NPV of 94.9%. Reasons for false‐positive findings include collateralization of flow in the presence of proximal ICA stenosis and prestenotic to stenotic MCA velocity ratios of 1:≤2. Conclusion. TCD is both sensitive and specific in identifying ≥50% intracranial arterial stenosis. A MFV threshold cutoff of 100 cm/s has an optimal sensitivity and specificity trade‐off for ≥50% MCA stenosis. To help avoid false‐positive results, a prestenotic to stenotic MCA velocity ratio of 1:≥2 should be used in addition to the MFV threshold.
Transcranial Duplex Imaging With a Sulfurhexafluoride Echocontrast Agent: Enhancement and Diagnostic Quality
Authors: Schweikert K. , Operschall C. , Llull J. B. , Lyrer P.
Published: November 2009

Background and Purpose. The authors investigate characteristics of ultrasound enhancement and diagnostic quality of a sulfurhexafluoride(SF6)‐containing echocontrast agent (SonoVue™) in cerebrovascular patients with insufficient temporal bone window by transcranial color‐coded duplex (TCCD) sonography. Methods. Thirty patients (mean age = 62.2 ±11.1 years) were enrolled. SF6 was administered intravenously in 4 different doses (0.3, 0.6, 1.2, and 2.4 mL). By videotape analysis, time to contrast appearance, duration of contrast enhancement, and duration of clinically useful signal enhancement were measured. Overall quality of ultrasound investigation was also assessed. Results. Time to contrast appearance ranged from 11 to 74 seconds (mean = 26 seconds). For the 0.3, 0.6, 1.2, and 2.4 mL doses, average times to contrast appearance of 30 ±12 seconds, 28 ±10 seconds, 23 ±8 seconds, and 22 ±6 seconds were measured. Duration of TCCD signal enhancement was 438 ±169 seconds, 483 ±195 seconds, 713 ±299 seconds, and 788 ±344 seconds for the different doses. Clinically useful enhancement was 160 ±124 seconds, 200 ± 157 seconds, 260 ±166 seconds, and 327 ±239 seconds. Conclusions. Administration of SonoVue led to a quality improvement in 21 patients. In TCCD, it optimizes visualization of the cerebral arteries in patients with inadequate bone window. A dose of at least 1.2 mL provides the best enhanced images.
Three‐dimensional Intraoperative Ultrasound of Vascular Malformations and Supratentorial Tumors
Authors: Woydt Michael , Horowski Anja , Krauss Juergen , Krone Andreas , Soerensen Niels , Roosen Klaus
Published: November 2009

The benefits and limits of a magnetic sensor‐based 3‐dimensional (3D) intraoperative ultrasound technique during surgery of vascular malformations and supratentorial tumors were evaluated. Twenty patients with 11 vascular malformations and 9 supra‐tentorial tumors undergoing microsurgical resection or clipping were investigated with an interactive magnetic sensor data acquisition system allowing freehand scanning. An ultrasound probe with a mounted sensor was used after craniotomies to localize lesions, outline tumors or malformation margins, and identify supplying vessels. A 3D data set was obtained allowing reformation of multiple slices in all 3 planes and comparison to 2‐dimensional (2D) intraoperative ultrasound images. Off‐line gray‐scale segmentation analysis allowed differentiation between tissue with different echogenicities. Color‐coded information about blood flow was extracted from the images with a reconstruction algorithm. This allowed photorealistic surface displays of perfused tissue, tumor, and surrounding vessels. Three‐dimensional intraoperative ultrasound data acquisition was obtained within 5 minutes. Off‐line analysis and reconstruction time depends on the type of imaging display and can take up to 30 minutes. The spatial relation between aneurysm sac and surrounding vessels or the skull base could be enhanced in 3 out of 6 aneurysms with 3D intraoperative ultrasound. Perforating arteries were visible in 3 cases only by using 3D imaging. 3D ultrasound provides a promising imaging technique, offering the neurosurgeon an intraoperative spatial orientation of the lesion and its vascular relationships. Thereby, it may improve safety of surgery and understanding of 2D ultrasound images.
Hemodynamic Effects of Innominate Artery Occlusive Disease on Anterior Cerebral Artery
Authors: Tan Teng‐Yeow , Lien Li‐Ming , Schminke Ulf , Tesh Paul , Reynolds Patrick S. , Tegeler Charles H.
Published: November 2009

Stenoses of the innominate artery (IA) may affect flow conditions in the carotid arteries. However, alternating flow in ipsilateral anterior cerebral artery (ACA) due to IA stenosis is extremely rare. A 49‐year‐old woman who was evaluated for symptomatic cerebrovascular disease presented with right latent subclavian and right carotid system steal. Transcranial Doppler examination displayed systolic deceleration wave‐forms in the right terminal internal carotid artery and alternating flow in the right ACA. Magnetic resonance angiography demonstrated tight stenosis of the right IA. For a thorough study of the hemodynamic effects of IA stenosis, a combination of duplex and transcranial Doppler examination is required.
Isolated Pontine Progressive Multifocal Leukoencephalopathy: Unusual Magnetic Resonance Imaging Features
Authors: Rubin Devon I. , Norris Steven , Flint Robert
Published: November 2009

Progressive multifocal leukoencephalopathy (PML) is an uncommon opportunistic infection that causes focal or multifocal demyelination predominantly in the subcortical white matter. The authors describe the clinical and radiographic features in 2 unusual cases of PML that were initially isolated to the pons. One patient presented clinically with only an isolated sixth cranial nerve palsy.
Neuroimaging of Acute Cerebellitis
Authors: Montenegro Maria Augusta , Santos Sérgio L. M. , Min Li Li , Cendes Fernando
Published: November 2009

Acute cerebellitis is one of the main causes of acute cerebellar dysfunction in childhood and may be infectious, postinfectious, or postvaccination. The etiology of acute cerebellitis is usually viral. Varicella zoster, Epsten‐Barr, rubeola, pertussis, diphtheria, and coxsackie viruses are the most frequently involved agents. Diagnosing of acute cerebellitis can sometimes be difficult because the patient may present only mild cerebellar signs and the examination of cerebrospinal fluid may be normal. The authors present the clinical and neuroimaging findings of 2 patients presenting with acute cerebellitis. Their magnetic resonance imaging showed hyperintense signal of cerebellar gray matter in T2‐weighted sequences, which is a strong indication of a diagnosis of acute cerebellitis.
Pitfall of Electron Beam Computed Tomography Angiography in Diagnosis of Subclavian Steal Syndrome
Authors: Ratanakorn Disya , Laothamatas Jiraporn , Pongpech Sirintra , Tirapanich Wiwat , Yamwong Sukit
Published: November 2009

A patient presented with vertebrobasilar insufficiency during exertion. Vertebral duplex and transcranial Doppler ultrasonography showed reversal of flow in both intracranial and extracranial vertebral and basilar arteries, suggesting bilateral subclavian and vertebrobasilar steal. Electron beam computed tomography angiography (CTA) showed no evidence of subclavian artery stenosis including normal vertebral artery origin on both sides. However, digital subtraction angiography revealed complete occlusion of both subclavian arteries with retrograde flow from both vertebral and basilar arteries to reconstitute both subclavian arteries. This false‐negative finding on CTA in detection of subclavian steal syndrome (SSS) is due to inappropriate contrast administration technique and postprocessing method, inability to differentiate flow direction, and lack of hemodynamic time sequences. This study demonstrates a pitfall of CTA in diagnosis of SSS compared to more reliable hemodynamic information obtained by duplex and transcranial Doppler ultrasonography, and digital subtraction angiography.
Hyperintense Basal Ganglia on T1‐Weighted Magnetic Resonance Images in a Patient With Common Variable Immunodeficiency Associated With Elevated Serum Manganese
Authors: Siger‐Zajdel Malgorzata , Selmaj Krzysztof
Published: November 2009

The authors report on a 32‐year‐old man with common variable immunodeficiency and high signal intensity in basal ganglia on T1‐weighted images. No signal alteration on T2‐weighted and postcontrast images was observed. The patient had elevated levels of manganese in the serum. The authors conclude that the unusual hyperintensity in the basal ganglia area on T1‐weighted images resulted from manganese deposition due to liver dysfunction.
Elevated Basal Ganglia Glucose Metabolism in Cyclosporine Neurotoxicity: A Positron Emission Tomography Imaging Study
Authors: Meyer Michael Andrew
Published: November 2009

Abnormally increased 18F‐fluorodeoxyglucose uptake in the basal ganglia was noted by positron emission tomography (PET) in a 37‐year‐old bone marrow transplant patient who had severe intention tremors of his hands and a progressive psychiatric change with social withdrawal and flat affect. This is the first PET report on metabolic abnormalities in cyclosporine neurotoxicity. It emphasizes the need for more research to understand the pathophysiology of these changes.
Assessment of Intracranial Collateral Flow by Transcranial Color‐Coded Duplex Sonography Using a Temporal and Frontal Axial Insonation Plane
Authors: Stolz Erwin , Mendes Irene , Gerriets Tibo , Kaps Manfred
Published: November 2009

Background and Purpose. The insonation of the posterior communicating artery (PcomA) is often hampered by the unfavorable insonation angle when the temporal acoustic bone window (TBW) is used. This problem may be ameliorated by a lateral frontal bone window (LFBW). This study evaluated the TBW and LFBW for the assessment of collateral intracranial flow conditions and aimed at defining diagnostic transcranial color‐coded duplex sonography (TCCS) criteria that do not need compression maneuvers. Methods. The A1 segment of the anterior cerebral artery (ACA), the PcomA, and the P1 segment of the posterior cerebral artery (PCA) were insonated by TCCS in 40 controls and 20 patients (16 internal carotid artery [ICA] occlusions or high grade stenoses, 3 middle cerebral artery stenoses or occlusions, 1 PCA stenosis). Results. Detection rates for the A1 ACA and P1 PCA were higher for the TBW (94%, 98%) compared to the LFBW (86%, 81%) in controls. The PcomA was identified more frequently through the LFBW (86%) compared to the TBW (80%). Through the LFBW angle, corrected flow velocity (FV) measurements were possible for the PcomA with an average correction of 6.5 degrees. In controls, in > 80% of identified PcomAs, flow was directed towards the ICA. Side to side differences were below 7% for peak systolic FVs. In the patients with ICA disease, a flow reversal in the ipsilateral A1 ACA and a FV difference of > 30% seemed feasible for diagnosis of anterior communicating artery crossflow. Criteria for PcomA crossflow were side differences of FVs in the PcomA of ≥ 30% and in the P1 PCA of ≥ 20%. Conclusions. The LFBW proved useful as a complementary insonation plane to assess intracranial crossflow conditions, especially via the PcomA. We were able to define TCCS criteria for functional relevant collateralization without the need of compression maneuvers.
Extracranial Internal Carotid Artery Occlusion: The Role of Common Carotid Artery Volume Flow
Authors: Tan Teng‐Yeow , Schminke Ulf , Lien Li‐Ming , Eicke B. Martin , Tegeler Charles H.
Published: November 2009

Background and Purpose. Quantitative measurement of blood flow volume in the common carotid artery (CCA) is now possible using the color velocity imaging quantification (CVI‐Q) ultrasound technique. The aim of this study was to evaluate the cerebral hemodynamic effects of unilateral internal carotid artery (ICA) occlusion on CCA blood flow volumes (FVs) using CVI‐Q. Methods. Records of ultrasound studies in our neurosonology laboratory were retrospectively reviewed to identify patients with unilateral ICA occlusions who at a minimum received both a routine color duplex carotid ultrasound examination and quantitative measurement of FV in the CCA, bilaterally, using the CVI‐Q method. A total of 71 patients met criteria and were included in the cohort. A side to side comparison was performed for FV, peak systolic velocities (PSV), end‐diastolic velocities (EDV), and resistance indices (RIs) in the CCA. Results correlated with any other available data such as flow direction in the ophthalmic artery and the presence of intracranial collateralization. Results. The FV, PSV, and EDV were significantly reduced, and the RI was significantly increased in the CCA on the side of the occlusion. A subgroup analysis in patients who also had an examination of the ophthalmic (n= 61) and the intracranial arteries of the Circle of Willis (n= 50), showed significantly higher FV in the CCA on the side of the occlusion if there was also reversed flow in the ophthalmic artery on the side of the occlusion (344 ± 144 ml/min versus 169 ± 53 ml/min). Conclusion. Quantitative FV measurement using CVI‐Q ultrasound can identify clear alterations in volume flow, collateral pathways, and cerebral hemodynamics in patients with unilateral ICA occlusion. It is a complementary tool, providing additional objective information about the cerebral hemodynamic effects of ICA occlusion that goes beyond what is available using routine flow velocity data.
Meningitis Complicating an Occult Infected Nasal Epidermoid Cyst in a Child
Authors: Hsu Mu‐Ling , Chen Cheng‐Yu , Lien Yiao‐Hsiang , Wang Chih‐Chien , Yuh Yeong‐Seng , Chen Shyi‐Jou
Published: November 2009

Congenital nasal epidermoid cyst without associated facial dysmorphism is an uncommon anomaly that is often asymptomatic. We report a case of occult nasal epidermoid cyst in a 12‐year‐old boy with initial nonspecific symptoms of fever, headache, abdominal pain, vomiting, and diarrhea. An enhanced magnetic resonance imaging (MRI) showed a cystic lesion in the frontal skull base with expansion of the foramen cecum and the perpendicular plate of the ethmoid bone, accompanied with meningitis. An emergent surgical intervention was undertaken, and an infected epidermoid cyst was confirmed by pathology. He recovered uneventfully during a 4‐week treatment with parentally‐administered antibiotics. This significant case report demonstrates the importance of MRI in the early diagnosis of a life‐threatening intracranial infection from an otherwise occult infected congenital nasal epidermoid cyst in children.
Echocardiographic Findings of Patients With Retinal Ischemia or Embolism
Authors: Mouradian Mikael , Wijman Christine A. C. , Tomasian Douglas , Davidoff Ravin , Koleini Behrooz , Babikian Viken L.
Published: November 2009

Background and Purpose. A potential source of emboli is not detected in more than 50% of patients with retinal arterial occlusive events. Echocardiographic studies are not always included in the diagnostic workup of these patients. The authors studied the diagnostic yield of transthoracic (TTE) and/or transesophageal (TEE) echocardiography in identifying potential sources of emboli in patients with retinal ischemia or embolism. Methods. In a prospective study, 73 consecutive patients with clinically diagnosed retinal ischemia or embolism received a standardized diagnostic workup including retinal photography, echocardiography, and imaging studies of the internal carotid arteries. TTE was performed in 83.6% of patients, TEE was performed in 5.5% of patients, and both TTE and TEE were per‐formed in 11.0% of patients. Ophthalmological diagnoses consisted of amaurosis fugax (n= 28), asymptomatic cholesterol embolism to the retina (n= 34), and branch or central retinal artery occlusion (n= 11). Results. Echocardiography identified a potential cardiac or proximal aortic source for embolism in 16 of 73 (21.9%) patients, including 8 who also had either atrial fibrillation or internal carotid artery stenosis of more than 50% on the side of interest. Thus, 8 of 73 (11.0%) patients had lesions detected only by echocardiography. The most commonly identified lesions were proximal aortic plaque of more than 4 mm thickness (n= 7, 9.6%) and left ventricular ejection fraction of less than 30% (n= 6, 8.2%). TEE was particularly helpful in identifying prominent aortic plaques. Conclusion. Echocardiography frequently identifies lesions of the heart or aortic arch that can act as potential sources for retinal ischemia or embolism. Further studies are needed to evaluate the prognostic and therapeutic relevance of these findings.
Insonation Method and Diagnostic Flow Signatures for Transcranial Power Motion (M‐Mode) Doppler
Authors: Alexandrov Andrei V. , Demchuk Andrew M. , Burgin W. Scott
Published: November 2009

Background and purpose. Power motion mode Doppler (PMD) simultaneously displays flow signal intensity and direction over several centimeters of intracranial space. Insonation protocol for PMD and spectral transcranial Doppler (TCD) with typical PMD flow signatures is described in serial patients with acute stroke symptoms examined via conventional windows with a PMD/ TCD unit. Results. Thirty‐five patients were studied within 12 hours after stroke onset (age 64 ±15 years; 8 received intravenous and 3 intra‐arterial thrombolysis). One patient had no temporal window, and 3 patients had suboptimal windows. In 90% of patients, PMD showed more than 1 ipsilateral temporal windows. In 63% of patients (n= 22), PMD simultaneously displayed the entire M1 (65–45 mm) and proximal M2 (45–30 mm) flows, leading to spectral TCD examination of the proximal M2 middle cerebral artery (MCA) in 28 of 35 patients (80%). All patients had sufficient foraminal (depth display = 60–110 mm) and orbital (depth display = 30–80 mm) windows. PMD displayed the entire basilar artery stem (75–100+ mm) in 69% (n= 24) of patients, and the distal basilar flow was detected in all patients by both PMD and TCD. TCD results were normal (12), proximal intracranial stenosis (5), large vessel occlusion (17), and cerebral circulatory arrest (1). Compared to spectral TCD, PMD signatures of similar diagnostic significance were low resistance (vessel identification and recanalization), high resistance (ophthalmic artery identification and distal obstruction), collateral (communicating arteries and leptomeningeal flow), reverberating (circulatory arrest), and branch embolization. Conclusions. PMD is a window‐finding tool and a guide for spectral TCD gate placement. PMD facilitates flow detection in the M2 branches and the distal basilar artery. PMD can demonstrate recanalization of the entire MCA main stem and proximal branches, increase the yield of embolus detection and procedure monitoring, and facilitate abnormal flow pattern recognition.
Reorganization of Motor Representation in a Patient with Epilepsia Partialis Continua as Shown by [O15]‐Labeled Butanol Positron Emission Tomography and Functional Magnetic Resonance Imaging
Authors: Stoeckel M. C. , Kleinschmidt A. , Ebner A. , Witte O. W. , Seitz R. J.
Published: November 2009

The authors investigated a 38‐year‐old patient with focal cortical dysplasia in the right precentral cortex using positron emission tomography and functional magnetic resonance imaging to localize the hand and finger motor representations. The patient presented clinically with epilepsia partialis continua, supposed to originate from the perirolandic area harboring the cortical malformation. Both methods revealed an abnormal bilateral activation of motor cortex during left‐hand finger movements. The results suggest that the so‐called eloquent but nevertheless pathological dysplastic cortex accommodates motor representations.
A Reinvestigation of Maximal Signal Drop in Dynamic Susceptibility Contrast Magnetic Resonance Imaging
Authors: Liu Yi‐Jui , Chung Hsiao‐Wen , Huang Ing‐Jye , Wang Fu‐Nien , Chin Shy‐Chyi , Lee Chang‐Shin , Chen Cheng‐Yu
Published: November 2009

Background and Purpose. The purpose of this study was to reevaluate the usefulness of relative maximum signal drop (rMSD), as compared to relative cerebral blood volume (rCBV) and cerebral blood flow (rCBF), in dynamic susceptibility contrast magnetic resonance imaging (MRI). Methods. Twenty‐five patients (11 with cerebral gliomas and 14 with infarcts of middle cerebral arterial territories) were included. The rMSD values were measured from 83 regions of interest and compared with measurements from corresponding rCBV and rCBF maps. Results. In stroke patients, rMSD correlated strongly with rCBF (r= 0.96) but only fairly with rCBV (r= 0.69). The absence of an association between rMSD and rCBV was evident in regions of increased contrast bolus dispersion. In glioma patients, the correlation of rMSD with rCBF (r= 0.85) was similar to that of rMSD with rCBV (r= 0.80). The interparameter associations were well predicted by computer simulations. Conclusions. The authors conclude that rMSD is as useful as rCBF under a variety of pathophysiological conditions, whereas in conditions with normal mean transit time, such as brain tumors, rMSD provides equivalent blood volume information to rCBV. The simplicity of rMSD maps could lead to the increased use of perfusion‐weighted MRI.
Functional Magnetic Resonance Imaging in Acute Unilateral Optic Neuritis
Authors: Russ Michael O. , Cleff Ulrich , Lanfermann Heinrich , Schalnus Rainer , Enzensberger Wolfgang , Kleinschmidt Andreas
Published: November 2009

Despite good clinical criteria for diagnosing optic neuritis (ON), only a few techniques can precisely assess its impact on visual brain function. The authors studied whether functional magnetic resonance imaging (fMRI) of visual activation reliably reflects the cerebral consequences of acute unilateral ON, and how fMRI correlates with clinical function and visual evoked potentials (VEPs). Twenty ON patients, before and after steroid treatment, were compared to 20 controls. Each eye was stimulated separately with a checkerboard pattern reversing at 1, 2, 4, and 8 Hz. VEPs were recorded the same day. Initially, affected eye responses differed significantly from those of unaffected counterparts and controls in 12 patients. Post hoc classification by fMRI criteria was correct in ∼ 85%. fMRI and VEP response parameters (as well as visual acuity) correlated significantly. The higher stimulation frequencies yielded greater fMRI responses from unaffected eyes, but not from affected eyes, in controls. The fMRI responses were quantifiable in every subject, whereas in 11 ON eyes, no VEPs were obtained during the acute stage. The authors conclude that fMRI is sensitive to the cerebral response alteration during ON and might therefore contribute to evaluating the temporal evolution of the visual functional deficit during recovery or therapy.
Susceptibility Contrast and Arterial Spin Labeled Perfusion MRI in Cerebrovascular Disease
Authors: Wolf Ronald L. , Alsop David C. , McGarvey Michael L. , Maldjian Joseph A. , Wang Jiongjiong , Detre John A.
Published: November 2009

Purpose. To directly compare dynamic susceptibility contrast (DSC) and continuous arterial spin labeled (CASL) magnetic resonance (MR) perfusion techniques in patients with known cerebrovascular disease, with the goals of identifying possible pitfalls in interpretation and determining potential for a complementary role in this setting. Methods. DSC and CASL MR perfusion studies were performed and compared in 11 patients with acute and/or chronic cerebrovascular disease. Using an automated segmentation technique, Pearson correlation coefficients were generated for CASL perfusion measurements compared to DSC perfusion maps (time‐to‐peak [TTP], relative cerebral blood volume [rCBV], cerebral blood flow [rCBF], and mean transit time [MTT]) by hemisphere and vascular territory. Results. TTP maps obtained using DSC perfusion MR correlated best both subjectively and objectively with CASL perfusion MRmeasurements when all patients studied were considered. If patients with a major transit delay were excluded, DSC rCBF correlated best with CASL CBF measurements. Conclusion. There may be a complementary role for CASL and DSC perfusion MR methods in cerebrovascular disease, especially in the setting of a marked transit delay.
Transcranial Doppler Markers of Diffusion‐Perfusion Mismatch
Authors: Restrepo Lucas , Razumovsky Alexander Y. , Ziai Wendy , Barker Peter B. , Beauchamp Norman J. , Wityk Robert J.
Published: November 2009

Background and Purpose. During the evaluation of acute ischemic stroke with diffusion‐ and perfusion‐weighted magnetic resonance imaging (DWI and PWI, respectively), the presence of salvageable brain tissue is suggested by the occurrence of a perfusion‐diffusion “mismatch.” DWI and PWI, however, are not universally available and have inherent inconveniences, which justify a search for practical diagnostic alternatives. The purpose of this study is to investigate whether there are transcranial Doppler (TCD) markers of mismatch. Methods. Retrospective analysis of 22 patients with acute ischemic stroke affecting the middle cerebral artery (MCA) territory, who had a TCD performed within 24 hours of magnetic resonance imaging (MRI) with DWI and PWI. Results. MRI and TCD were performed on average 10.8 ± 9.2 hours apart. Time from symptom onset to MRI and TCD completion were 1.6 ± 1.6 and 2 ± 1.9 days, respectively. MCA and intracranial internal carotid artery (ICA) cerebral blood flow velocity (CBFV) asymmetry, together with a large ICA‐to‐MCA gradient, were associated with the presence of mismatch. The combined use of 2 TCD parameters (MCA CBFV asymmetry of ≥30% and ICA‐to‐MCA gradient ≥20 cm/sec) had a sensitivity of 75%, specificity of 80%, positive predictive value of 82%, and negative predictive value of 73% at detecting mismatch cases. Conclusions. Diffusion‐perfusion mismatch appears to be associated with interhemispheric asymmetry between MCA and ICA CBFVs, and a large CBFV gradient between the ICA and MCA on the affected side. Prospective studies are required to verify these observations and to determine whether TCD can be used to follow patients with mismatch.
Ipsilateral Hemiplegia in a Lateral Medullary Infarct– Opalski's Syndrome
Authors: Kimura Yasuyuki , Hashimoto Hiroyuki , Tagaya Masafumi , Abe Yuko , Etani Hideki
Published: November 2009

A 42‐year‐old man was admitted complaining of the sudden onset of headache, vomiting, vertigo, and gait disturbance. The authors found hemiparesis of his right limbs, right Horner's syndrome, and decreased pain and temperature sensation of his right face and left limbs. Diffusion‐weighted imaging (DWI) showed an acute small infarct located on the right side of the lateral lower medulla. This is the first report of Opalski's syndrome with lower medullary infarction detected by DWI.
Diffusion‐Weighted MRI in Creutzfeldt‐Jakob Disease: A Better Diagnostic Marker Than CSF Protein 14‐3‐3?
Authors: Mendez Oscar E. , Shang Jingzi , Jungreis Charles A. , Kaufer Daniel I.
Published: November 2009

Two middle‐aged patients presented with rapidly progressive dementia and ataxia, nonspecific electroencephalography findings, and negative cerebrospinal fluid (CSF) protein 14‐3‐3. Both patients underwent brain magnetic resonance imaging (MRI) scans that demonstrated abnormalities on diffusion‐weighted imaging (DWI) sequences, and both were later confirmed to have Creutzfeldt‐Jakob disease (CJD) by tissue examination. Because a recent position paper from the American Academy of Neurology characterized CSF protein 14‐3‐3 as a gold standard for clinically diagnosing CJD, the authors reviewed studies of CJD in which DWI‐MRI imaging and CSF protein 14‐3‐3 studies were both performed. Among 19 reported cases of CJD with DWI‐MRI lesions, CSF protein 14‐3‐3 was negative in 6 cases and positive in 2 others. The authors' findings suggest that multifocal cortical and subcortical hyperintensities confined to gray matter regions in DWI‐MRI may be a more useful noninvasive diagnostic marker for CJD than CSF protein 14‐3‐3. These observations provide a compelling rationale for a prospective comparative study.
Reversal of Perfusion and Diffusion Abnormalities After Intravenous Thrombolysis for a Lacunar Infarction
Authors: Chalela Julio A. , Ezzeddine Mustapha , Latour Lawrence , Warach Steven
Published: November 2009

Perfusion and diffusion magnetic resonance imaging (MRI) have been used to guide therapy in patients with large vessel occlusions. In an analogous fashion, the authors used perfusion and diffusion MRI to demonstrate a perfusion deficit and a matching diffusion lesion in a patient with lacunar infarct. Following thrombolytic therapy, the authors observed a reversal of the perfusion deficit, the diffusion lesion, and clinical recovery. This case suggests that perfusion and diffusion MRI may be informative in patients with lacunar infarction who are candidates for thrombolysis.
Variability and Validity of a Simple Visual Rating Scale in Grading White Matter Changes on Magnetic Resonance Imaging
Authors: Fan Yu Hua , Lam Wynnie W. M. , Mok Vincent C. T. , Huang Ru Xun , Wong Ka Sing
Published: November 2009

Background and Purpose. A new simple visual rating scale can be used in magnetic resonance imaging (MRI) to grade the severity of white matter changes (WMC). The authors sought to study the interobserver variability and the validity of this visual rating scale against a computer‐aided quantitative method in measuring WMC. Methods. The authors examined 220 magnetic resonance images from stroke‐free patients with traditional risk factors for atherosclerosis and middle cerebral artery stenosis who were participants in a clinical trial requiring MRI examination. The severity of WMC was graded from 0 (no WMC) to 3 (severe WMC). For the quantitative assessment of WMC, the volume of WMC were measured with a computer‐aided, automated segmentation method. The interobserver variability was also determined. Results. The mean volumes were significantly different among the different groups, which were scored 1, 2, and 3 (1324.59, 6475.48, and 25,440.05 mm3, respectively; 1‐way analysis of variance, P < .001). Interobserver variability for grading WMC was good in different locations of the brain. Excellent results were found in the frontal lobe (κ=0.829) and the parietal‐occipital lobe (κ=0.646), whereas poor results were found in the basal ganglia (κ=0.391). There was perfect agreement between the 2 observers in 89.1% for the frontallobe and 77.0% for the parietal‐occipital lobe. Conclusions. The results suggest that this simple visual rating scale is a valid and reliable method for grading WMC in the lobar region but not in the basal ganglion.
Subcortical Hypointensity in Partial Status Epilepticus Associated with Nonketotic Hyperglycemia
Authors: Seo Dae Won , Na Dong Gyu , Na Duk L. , Moon So Young , Hong Seung Bong
Published: November 2009

Transient gray and white matter magnetic resonance signal changes have frequently been reported because of underlying epileptic activity. However, transient subcortical hypointensity on T2 and fluid‐attenuated inversion recovery images in the setting of status epilepticus (SE) has rarely been reported. The authors note 3 of 6 retrospective cases with partial SE associated with nonketotic hyperglycemia showing transient subcortical T2 hypointensity near the epileptic focus. These changes may be due to the accumulation of free radicals and iron deposition related to a hyperglycemia‐induced hypoxic‐ischemic state.
Bilateral Internal Carotid Artery Dissection Mimicking Inflammatory Demyelinating Disease
Authors: Lie C. , Schwenk S. , Szabo K. , Lanczik O. , Hennerici M. G. , Gass A.
Published: November 2009

Background and Purpose. Internal carotid artery (ICA) dissection (ICAD) may be extremely difficult to diagnose only on the basis of historical information and clinical signs, and even standard brain imaging (computed tomography [CT], T2‐weighted magnetic resonance imaging [MRI]) may not be sufficient to delineate the underlying pathology clearly, as shown in this case. Methods. The clinical presentation and parenchymal lesion pattern on CT were suggestive of inflammatory demyelinating disease, and additional multiparametric MRI was per‐formed. Results. Diffusion‐weighted MRI, magnetic resonance angiography, and perfusion‐weighted MRI revealed acute ischemic lesions, bilateral ICA obstruction, and bilateral hypoperfusion in the middle cerebral artery territories. Bilateral ICAD was confirmed by Doppler and duplex ultrasound, and anticoagulation therapy was initiated. A follow‐up examination showed recanalization of the obstructed ICAs and the normalization of cerebral perfusion. Conclusion. This case illustrates the importance of demonstrating the pathology and the value of multiparametric MRI techniques for the diagnosis and monitoring of ICAD and its hemodynamic consequences.
“Congenital” Horner's Syndrome and Carotid Dissection
Authors: Robertson William C. , Pettigrew L. Creed
Published: November 2009

The authors describe a child presenting with Horner's syndrome after the repeated application of birthing forceps to the head and neck during vaginal delivery. Magnetic resonance imaging and angiography confirmed that the proximal right internal carotid artery (ICA) showed injury caused by dissection. Carotid duplex and transcranial ultrasonography provided supporting evidence of distal right ICA occlusion with the development of intracranial collaterals. The authors interpret these findings to indicate that the child suffered a traumatic dissection of the distal right ICA to mimic “congenital” Horner's syndrome (CHS). In a review of English medical literature published since 1972, the authors found 70 cases of CHS, none of which was attributed to carotid dissection. This case demonstrates that carotid dissection is an underreported cause of CHS.
Voxel‐Based Mapping of Cortical Ischemic Damage Using Tc 99M L, L‐Ethyl Cysteinate Dimer Spect in Acute Stroke
Authors: Mahagne Marie‐Hélène , David Olivier , Darcourt Jacques , Migneco Octave , Dunac Antoine , Chatel Marcel , Baron Jean‐Claude
Published: November 2009

Background and Purpose. When performed soon after stroke onset, single‐photon emission computed tomography (SPECT) with hexamethylpropylenamine oxime or Tc 99m L, L‐ethyl cysteinate dimer (ECD) has significant added predictive value compared to neurological scores. With ECD SPECT, the degree of tracer uptake reduction predicts neurological recovery, and using a 40% threshold to characterize irreversibly damaged tissue (IDT), significant correlations have been observed. How‐ ever, correlations between this uptake threshold and tissue out‐ comes have not been assessed. The purpose of this study was to validate the 40% ECD uptake threshold for the probabilistic mapping of IDT using an automatic, voxel‐based approach. Methods. In 10 acute stroke patients, the authors first com‐ pared early ECD SPECT and late coregistered magnetic reso‐ nance imaging (MRI) data and assessed for IDT and “tissue at risk” (ie, tissue with ECD uptake below and above 40%) the per‐ centage of voxels ultimately infarcted and noninfarcted on late brain MRI. They then assessed the correlations between the vol‐ umes of brain tissue compartments and subsequent neurologi‐ cal recovery. Finally, to assess whether visual SPECT analysis is reliable compared to the more complexvoxel‐based approach, the authors compared the predictive value of the 2 methods for neurological recovery. Results. The majority of IDT voxels (aver‐ age = 84%), defined by ECD uptake < 40%, evolved toward infarction, and 51.8% to 100% of at‐risk voxels (average = 89%) escaped infarction. The extent of IDT correlated significantly with neurological recovery (P= .0009). There was good agree‐ ment between visual and voxel‐based analyses (P= .0004). Conclusion. The results support the validity of the ECD uptake thresholds chosen, suggesting that ECD uptake can reflect neuronal viability and that ECD SPECT can be useful for the early detection of potentially salvageable tissue and irreversible damage. These preliminary results encourage the use of this method in a clinical setting for fast decision making in choosing acute therapy.
Brain Tissue Water Uptake after Middle Cerebral Artery Occlusion Assessed with CT
Authors: Dzialowski Imanuel , Weber Johannes , Doerfler Arnd , Forsting Michael , Von Kummer Rüdiger
Published: November 2009

Background and Purpose. To study whether computed tomography (CT) can measure the water content of early ischemic edema. Methods. The authors obtained cranial CT in 5 groups of rats subjected to 1 hour (n = 8),2 hours (n = 11),3 hours (n = 13),4 hours (n = 13), or 6 hours (n = 14) of right middle cerebral artery (MCA) occlusion. Immediately after CT, the authors removed the rats’ brains and determined tissue water content by the dry‐wet weight method. They correlated brain x‐ray attenuation with brain tissue water content. Results. Mean brain tissue water content remained constant in the nonischemic left hemispheres at 77.9%± 0.6% and increased up to 79.3%± 1.0% in the right hemispheres after 6 hours of permanent right MCA occlusion. X‐ray attenuation remained constant in the left hemispheres at 75.6 ± 2.2 Hounsfield units (HU) and decreased to 71.7 ± 3.4 HU in the right hemispheres after 6 hours of right MCA occlusion. The decrease in x‐ray attenuation correlated significantly with the increase in ischemic brain tissue water content (y= 217.3 – 1.8 ×x; r= .55, P < .0001). That means that a 1% increase in hemispheric tissue water content causes a decrease in x‐ray attenuation of 1.8 HU. Conclusions. After MCA occlusion, immediate brain tissue net water uptake is associated with a decrease in x‐ray attenuation. CT can monitor ischemic edema in an acute stroke.
Treatment of Marburg Variant Multiple Sclerosis with Mitoxantrone
Authors: Jeffery Douglas R. , Lefkowitz David S. , Crittenden Jeffrey P.
Published: November 2009

Marburg variant multiple sclerosis (MS) is a severe, sometimes monophasic, form of MS leading to advanced disability or death within a period of weeks to months. No consistently successful treatment for Marburg variant MS has been described. The case reported here is that of a 34‐year‐old woman with Marburg variant MS whose magnetic resonance imaging scan showed extensive brainstem, periventricular white matter, subcortical, and cortical involvement, giving the appearance of an “MS cerebritis.” The patient had no response to treatment with methylprednisolone but improved and recovered after treatment with mitoxantrone (MITX). Because MITX has potent anti‐inflammatory effects and demonstrated efficacy in worsening MS, it may be an appropriate agent for the treatment of Marburg variant MS.
Reliability of Semiquantitative Ultrasonic Perfusion Imaging of the Brain
Authors: Eyding Jens , Wilkening Wilko , Reckhardt Markus , Meves Saskia , Postert Thomas
Published: November 2009

Background and Purpose. Contrast burst depletion imaging (CODIM) visualizes cerebral perfusion by destruction of microbubbles and observation of image intensity course. Because of its complexity, artifacts occur. Criteria of reliability to improve diagnostic significance were created and validated. Methods and Results. Eighteeen healthy volunteers were examined with 2 echo contrast agents (ECAs) and 3 frame rates in 3 regions of interest (ROIs). Perfusion coefficient (PC), T min (time todecrease intensity to 10% of its max), and relative error (RE) (deviation of measured data from fitted model) were determined. PC differed significantly neither between CA nor between frame rates (overall mean = 1.60 ± 0.21 · 10 – 2s –1). Tmindiffered significantly between frame rate groups (P< .001, 33.4 ± 11.2 s/0.5 Hz; 3.6 ± 2.5 s/5 Hz) since it is related to destruction of microbubbles that occurs with each frame and to the perfusion rate. RE was higher in the Optison group and tended to decrease in ROIs closer to the probe. Conclusions. PC was independent of frame rate and ECA. T min was shorter with higherframe rates. Due to a very rapid decay at 5 Hz, the ideal frame rate should be about 1 Hz, that is, because the number of frames acquired within T min and therefore signal‐to‐noise ratio ishigher at 1 Hz. Since the algorithm is complex (high RE) and more artifacts should occur in patients (insufficient bone window, etc), a triggering of the insonations by, for example, heart rate could decrease artifacts and increase diagnostic power of CODIM.
Unstable Cerebral Hemodynamics in Carotid Artery Occlusion and Large Hemispheric Stroke: A Cerebral Blood Flow Volume Study
Authors: Niesen Wolf‐Dirk , Weiller Cornelius , Sliwka Ulrich
Published: November 2009

Purpose. In chronic internal carotid artery (ICA) occlusion, cere bral hemodynamics are likely to be stable due to collateral flow. The authors evaluated cerebral hemodynamics in ICA occlusion using the sonographic method of cerebral blood flow volume (CBVF) measurement to find differences that might identify patients with large hemispheric stroke in ICA occlusion.Methodand Results. The ultrasound method of CBVF measurement was used, which represents the sum of flow volumes of both internal carotid and both vertebal arteries. CBVF was measured in 29 patients with ICA occlusion including patients with (1) chronic ICA occlusion without acute minor stroke, (2) chronic ICA occlusion with acute minor stroke, (3) acute minor stroke due to acute ICA occlusion, and (4) ICA occlusion and large hemispheric stroke. In ICA occlusion, overall CBVF is lower compared to healthy volunteers, due to a significant reduction of CBVF in groups 3 and 4. Comparing groups, there were no differences in CBVF between groups 1, 2, and 3. CBVF in group 4 is reduced compared to all other groups. By receiver‐operating characteristic analysis, a CBVF cutoff value for large hemi spheric stroke was computed with a sensitivity of 100% and a specificity of 95.8%.Conclusion. Stroke due to acute ICA occlusion is associated with decreased CBVF compared to chronic ICA occlusion. Moreover, ICA occlusion and large hemispheric stroke are associated with decreased CBVF compared to all other groups, indicating instability of cerebral hemodynamics. CBVF measurement thus may be a useful tool in predicting large middle cerebral artery stroke early in ICA occlusion.