bluuebunny/crossref_metadata_2025 huggingface dataset:
Is a Low End-Diastolic Velocity Parameter Enough to Exclude an 80–99% Internal Carotid Artery Stenosis?
Authors: Parein Craig S.
Published: March 2018

Introduction

—High resistive internal carotid artery (ICA) waveforms (high peak systolic velocity >250 cm/sec with low end-diastolic velocity (EDV) <125 cm/sec, having an external carotid artery waveform appearance) are uncommon and present a diagnostic challenge for intervention. Most ICA stenotic classifications rely on a greater EDV to delineate a critical stenosis of 80–99%.

Methods

—Review of a multiple-laboratory, single-center, Intersocietal Accreditation Commission-accredited, noninvasive vascular laboratory database for ICA carotid examinations performed from January 1, 2008 to November 1, 2012, with a positive stenotic range >60%. Medical records, archived ultrasound images, and correlative imaging studies were reviewed.

Results

—A total of 843 carotid duplex studies (1,686 arteries) positive for >60% stenoses of at least one side were reviewed. There were 102 duplex studies with high resistive ICA waveforms that were identified. Of these, 35 duplex studies had 40 correlative results, and 67 duplex studies did not have any correlative results. Of the 35 correlated duplex studies, median age was 78 years (range, 53–86 years). Gender distribution was 57% male. The median age of the male subjects was 77 years with a range of 63–82 years and the median age of female subjects was 73 years old with a range of 53–86 years. Seven of the 35 patients presented with symptoms of visual disturbance, transient ischemic attack, or syncope (21% symptomatic). Side distribution was 12 males and 8 females had right-side involvement, and 7 males and 7 females had left-side involvement. There was one female patient who had bilateral involvement. This provides us with 36 duplex ultrasound studies to correlate. Mean PSV was 369 cm/sec (range, 187–492 cm/sec). Mean EDV was 89 cm/sec (range 18–130 cm/sec). Average ICA/common carotid artery ratio was 6.2 (range, 3.2–12.5). Correlative computed tomography angiography was available for 12 of the studies, angiography for 10 of the studies, and surgical findings for 18 of the 35 studies.

Conclusion

—Assessing all Doppler parameter used to categorize an ICA stenotic range may be beneficial in determining the need for patient intervention. Sonographer impression of audible clues and cardiac history is helpful to the interpreting physician reviewing 2D images and waveforms.
Popliteal Vein Aneurysm: A Case Report
Authors: Shaub Michael , Akbari Cameron
Published: March 2018

Introduction

—Although popliteal vein aneurysms are the most common of all venous aneurysms, they are exceedingly rare. In fact, there have only been approximately 150 reported cases to present. We present a case of a popliteal vein aneurysm found in a patient with right lower-extremity symptoms.

Patient Description

—A 51-year-old woman presented with right lower-extremity pain and swelling and was evaluated for deep venous thrombosis via venous duplex ultrasound.

Methods

—Venous duplex ultrasound of the bilateral lower extremities was performed upon presentation to an outside hospital and again after referral to our vascular surgery service.

Results

—Original duplex as well as repeat after referral to our vascular surgery service were found to be negative for deep venous thrombosis but revealed a 2.7 by 2.1-cm fusiform popliteal vein aneurysm on the right (symptomatic) side.

Discussion

—Although many venous aneurysms are clinically insignificant, popliteal vein aneurysms present a poorly characterized risk for pulmonary embolism (some estimates are as high as 70–80%), which can be potentially fatal. Therefore, surgical repair is generally warranted, especially in cases in which the diameter is greater than 2.0–2.5 cm, as in this case. Our patient, however, declined surgical intervention despite this information. Thus, in addition to presenting our case as well as mentioning standard surgical techniques, we will briefly comment herein on the limited nonsurgical treatment options for popliteal venous aneurysms found in the literature.
Presence of Lower-Extremity Venous Pulsatility is not always the Result of Cardiac Dysfunction
Authors: Schroedter William B. , White Jean M. , Garcia Amy R. , Ellis Megan E.
Published: March 2018

Introduction

The presence of peripheral venous pulsatility is widely recognized and commonly attributed to cardiac dysfunction; however, the precise cause(s) have been poorly defined in the literature. We have noted multiple patterns of venous pulsatility, often in patients with no history of heart disease. In a normal, high compliance venous system, cardiac pulsatility is continually dampened with distance from the heart. We theorized that in a low-compliance system, the pulsatility would be transmitted throughout and its presence is a reflection of the hemodynamic state of the lower extremity venous system.

Methods

We evaluated the right popliteal vein in 30 normal volunteers (average age 35) with no history of heart disease and minimal venous disease (C-Class range 0–2, average 0.4). The right popliteal vein was chosen for its distal anatomic location and to avoid any potential of left iliac vein compression. Three spectral waveforms were obtained in the following manner: (1) a left lateral supine position with the right popliteal vein at the level of the right atrium, (2) after standing for >3″ with no right leg weight bearing or muscle contraction, and (3) after 10 seconds of vigorous plantar/dorsiflexion.

Results

In a supine position, all 30 limbs had normal respiratory phasicity with minor variation. In every patient, after quiet standing there was very low velocity forward flow with a discernable pulsatility. Immediately after dorsiflexion, flow became highly pulsatile.

Conclusion

A total of 100% of patients demonstrated highly pulsatile flow when the lower extremity venous system was filled to resting hydrostatic pressure. Although cardiac dysfunction may result in venous hypertension, reducing system compliance, the presence of pulsatile venous flow in the lower extremity can be demonstrated in all persons and is therefore a function of venous hemodynamics.
Duplex Ultrasound Protocol and Findings in Common Carotid Artery Dissection Extending from the Aortic Arch
Authors: Charlton-Ouw Kristofer M. , Sandhu Harleen K. , Burgess William , Vasquez Marla , Estrera Anthony L. , Azizzadeh Ali , Coogan Sheila M. , Safi Hazim J.
Published: March 2018

Introduction

Aortic dissection can extend into the brachiocephalic arteries. We analyzed carotid duplex ultrasound (CDU) in DeBakey I acute aortic dissection to identify characteristics and establish a protocol to ensure appropriate evaluation.

Method

From 2002 to 2011, patients with CDU and proximal aortic dissection were identified. The protocol included color Doppler in both long and short axis, spectral waveforms of true and false lumens, and imaging of the aortic arch, when appropriate. Imaging was performed on a Philips iE33 or iu22 using a 9–3 MHz linear array probe for the cervical carotid arteries and a curved array 5–1 MHz probe for the aortic arch. Waveforms were analyzed for signs of proximal dissection.

Results

CDU was performed in 87 of 288 patients and comprised the study group. Intimal flaps were noted in 26 common carotid arteries (CCAs) in 20 patients. The false lumen was thrombosed in nine arteries (35%). Eight CCAs had stenosis >50%, with seven having increased velocities >200 cm/sec. All patients with elevated velocities in the true lumen had false-lumen thrombosis. We noted that carotid artery dissections were not visualized in all planes and that more false lumens were found to be patent on CDU than on computed tomography. Characteristic waveforms included a second pulsed systolic waveform, a wide and jagged systolic peak, intermittent flow reversal, and visualization of a dissection flap.

Conclusion

Carotid imaging in transverse and axial planes is important in dissection cases. We found that a 5–1 MHz curved-array probe may be helpful in imaging the proximal brachiocephalic arteries and aortic arch. Several characteristic waveforms were noted. We recommend a standardized protocol that includes near-complete CCA visualization, multiplane views, and Doppler waveform analysis of both true and false lumens. The clinical significance of false-lumen patency or true-lumen stenosis remains unclear.
Incidental Finding of Traumatic Arteriovenous Fistula in the Tibial Peroneal Trunk during Venous Duplex Ultrasound to Rule Out Deep Vein Thrombosis
Authors: May Heidi , Griffiths Casey , Riggs Patrick
Published: March 2018

Traumatic arteriovenous (AV) fistulas are caused by injury to an adjacent artery and vein and can be potentially limb threatening. AV fistulas occurring at the level of the popliteal artery result in a 10% greater rate of amputation than those at the level of the common femoral artery. Clinical findings of AV fistula in the lower extremity are similar to that of deep vein thrombosis and include pain, swelling, and redness of the extremity. This case study demonstrates how a routine lower-extremity venous Duplex ultrasound led to the diagnosis of a traumatic AV fistula that required surgical repair. The patient presented to the emergency department with a cold foot and was found to have a thrombosed left iliac artery and femoral artery system. A thrombectomy catheter was used to remove the clot from the superficial femoral, above knee popliteal, and posterior tibial arteries. One week postoperatively, the patient had continued left thigh and calf pain and swelling; a lower-extremity venous ultrasound was ordered to rule out deep-vein thrombosis. Findings of the Duplex ultrasound were negative for deep-vein thrombosis; however, Doppler imaging revealed abnormal flow in both the venous and arterial systems of the left femoral and popliteal vessels. Venous flow was found to be continuous and turbulent. The arterial system had low resistance, marked spectral broadening, and high velocity. Normal venous flow is spontaneous, phasic, and pulsatile with respiration. Normal arterial flow in the lower extremities is high resistance and triphasic. Traumatic AV fistula was suspected in the tibial peroneal region, and confirmed with computed tomography angiography. The patient underwent surgical repair of fistula with vein graft.
Common Femoral Artery Pseudoaneurysm Associated with Arteriovenous Fistula
Authors: Bulauitan Constantine S. , McKean Robert , Cook Judith W.
Published: March 2018

Background

Thrombin injection (TI) is a common modality for the treatment of femoral artery pseudoaneurysm (PSA) of arterial access sites. It has decreased the need for open repair in this cohort of patients who often have increased surgical risk. Deep venous thrombosis and venous thromboembolism (VTE) have been reported after TI for PSA in the presence of an arteriovenous fistula (AVF). A combined treatment modality using ultrasound-guided TI with concomitant balloon occlusion of the AVF is described.

Patient

A high cardiac risk patient presented with a large pulsatile right groin mass after cardiac catheterization. Ultrasound identified a PSA arising from the right common femoral artery. The anatomy was suitable for TI; however, a large AVF also was present. The patient was a poor surgical candidate because of cardiac morbidity and body habitus.

Methods

The patient was taken to the hybrid vascular operative suite. Conscious sedation was administered. Venous access was obtained via the right internal jugular vein. Venography identified the AVF in the right common femoral vein. Thrombin was injected into the right groin PSA using direct ultrasound visualization. Simultaneous fluoroscopic-guided balloon inflation was used to occlude the common femoral vein and prevent flow through the AVF. Postinjection venography and Doppler examination of the femoral vessels were performed.

Results

The PSA was successfully occluded. There was no identifiable venous thrombus. Doppler examination also showed resolution of the AVF. There were no clinical signs or symptoms of pulmonary embolism.

Conclusion

TI of femoral artery PSA associated with AVF has increased risk of VTE. Concomitant venous occlusion during TI of a PSA may decrease the risk of VTE in the setting of a large AVF. This has the potential to expand the indications for TI in the high-risk surgical patient.
Pseudoaneurysm in a Bypass Graft
Authors: Nguyen Lisa , Dan Mei , Pak Laura K.
Published: March 2018

Sometimes a routine surveillance graft scan discloses something not so routine: in this case, giant pseudoaneurysms in the midsection of a lower-extremity bypass graft. This case report details a complication of cryopreserved vein grafts, underscoring the importance of routine surveillance imaging. It also illustrates adverse patient consequences that occur from a misdiagnosis with ultrasonography and demonstrates the critical role of the vascular sonographer in an integrated patient care team.
Impact of Bilateral Upper-Extremity Stenoses in the Diagnosis of Atherosclerotic Disease
Authors: Walsh Paula M.
Published: March 2018

Clinically significant differences in upper-extremity blood pressures usually are the result of atherosclerotic plaque, resulting in a reduction in blood pressure to one upper extremity. Less commonly, both upper extremities will have hemodynamically significant stenoses. Unrecognized, these bilateral stenoses put patients at an increased risk for cardiovascular events. The described patient presented to the emergency room with transient ischemic symptoms. Because of the low brachial blood pressures, bilaterally she was diagnosed and treated for hypotension as the result of dehydration. The patient's primary care provider subsequently referred the patient to the vascular laboratory where identification of the multiple, bilateral stenoses was made.
Analysis of Lost Sonographer Productivity in a University Hospital Vascular Laboratory
Authors: Hoffman Kaitlin , Evans Julie , Kershner Preston , Haurani Mounir J. , Satiani Bhagwan
Published: March 2018

Introduction

Improved efficiency is necessary to deliver cost effective services in today's healthcare environment. Details of how a vascular sonographer's (SG) time is allocated during an average working day have not been adequately described previously. Our objective was to provide insight into the SG average day, and therefore investigate ways at becoming more efficient. This improved efficiency may not only result in cost savings, but better patient and SG satisfaction.

Methods

SG at two hospitals affiliated with our university (Hospital A and B) tracked their activities daily during five consecutive weekdays. Scan time, delays in patient arrival, preparation for the test, computer entry, lunch breaks, and administrative time (patient and nonpatient related) were logged.

Results

Eleven SG performed 113 tests at Hospital A and 60 at Hospital B. On average, there were 5.4 full time equivalent (FTE) and 1.8 FTE SG working daily at Hospitals A and B respectively. Hospital A performed 62 portable studies, Hospital B performed none. Each SG performed between 14 and 32 tests (mean 21.4) in the study period. This was equivalent to 6.35 tests per FTE per day. Excluding portable studies, actual scan time occupied only 38.8% of the SG day. Nonpatient related but essential activities (23.7%) and nonscan nonessential activities (27.9%) took up the rest of the SG time.

Conclusion

In order to maximize efficiency in the vascular lab, nonpatient related activities, which occupy about a quarter of the daily workday, must be eliminated. Off-loading of these responsibilities to ancillary staff may improve SG efficiency. Portable studies consume a significant amount of time, and thus are a drag on efficiency as well.
The Role of Femoral Artery Ultrasound Measurements in Predicting Restenosis following Endovascular Intervention
Authors: Wang Grace J. , Shaw Pamela A. , Mohler Emile R. , Durinka Joel B. , Layne Andrew J. , Etherington Mark S. , Sehgal Chandra M. , Fairman Ronald M. , Ky Bonnie
Published: March 2018

Background

Although endovascular interventions for peripheral artery disease (PAD) have become increasingly common, they are associated with a significant rate of restenosis. An improved understanding of the risk factors for restenosis is needed to guide the management of patients with PAD.

Methods

We performed a cross-sectional analysis of 101 patients with PAD, to determine the association between clinical predictors, novel imaging measures of vascular function of the femoral artery [intima-media thickness, diameter, and intima-media cross-sectional area, change in diameter (delta diameter), average expansion and average contraction], and risk of reintervention. Univariable and multivariable associations between clinical and imaging measures and the need for reintervention were assessed using logistic regression. The predictive accuracy of the selected regression model and added predictive value of imaging measures were assessed using the area under the Receiver operating characteristic curve (AUC). The added predictive value of ultrasound was assessed by comparing AUC of the selected model with clinical parameters alone with that of the same model with additional ultrasound parameters.

Results

Of the 101 patients with PAD, 20 underwent recent multiple reinterventions. Vessel diameter was statistically significantly smaller in the group who underwent multiple reinterventions, p = 0.0170. Univariate logistic regression revealed that smoking status, hypertension, hypercholesterolemia, and chronic renal insufficiency were clinical parameters that met the statistical cut point of p ≤ 0.20. In the multivariable model, chronic renal insufficiency status (odds ratio (OR) = 8.27, 1.17–58.25), hypertension (OR = 0.145, 0.020–1.062), and femoral artery diameter (OR = 0.375, 0.136–1.031) remained important predictors for reintervention. The AUC for the clinical multivariable logistic regression model was 0.7481 while that for the model additionally including the ultrasound parameters was 0.8325 ( p = 0.044).

Conclusions

Including ultrasound parameters in the risk prediction model for restenosis improved the ability to predict restenosis in this group of patients with known PAD. Further study is needed to define its utility in preoperative assessment and risk stratification before revascularization.
Duplex Ultrasound Diagnosis and Follow-Up of Nutcracker Syndrome
Authors: Matthews Cheryl , Wilson Darlene , Demasi Richard , Nelms Courtney , Tuvell Nancy
Published: March 2018

Introduction

Nutcracker syndrome (NCS), also referred to as left renal vein entrapment, is characterized by left renal vein compression between the superior mesenteric artery and aorta. Treatment usually involves renal vein percutaneous angioplasty with or without stent placement. Patients frequently present to the vascular laboratory with vague complaints including various symptoms such as pelvic pain and hematuria. Duplex ultrasound (DU) can play a vital role in the initial diagnosis as well as serial follow-up post-intervention.

Case Report

Two female patients presented to our laboratory with symptoms ranging from left flank pain, lower quadrant pain, pelvic pain, and microscopic hematuria. Patient 1 was referred by her urologist. Patient 2 was referred after the computed tomography (CT) scan for left side pain indicated possible NCS. Inferior vena cava (IVC) duplex exams were performed with a Phillips iU22 using a C5-1 MHz curved transducer. DU revealed increased velocities in the left renal veins of each patient. Also, the renal veins appeared to be externally compressed. Subsequent venograms with intravascular ultrasound (IVUS) confirmed left renal vein stenosis in both patients. Left renal vein stents were placed in the patients. The stents were evaluated using DU within 1 week of intervention yielding excellent results.

Discussion

DU was useful in the diagnosis of both patients. If left untreated, NCS can cause damage to the left kidney leaving patients in pain for the rest of their lives. Several diagnostic modalities should be considered for diagnosis of this disease including IVC and renal DU, CT scan, magnetic resonance imaging, and venogram with IVUS.

Conclusion

NCS patients often present with vague symptoms and diagnosis can be difficult. When NCS is clinically suspected, DU is an excellent primary diagnostic method with which to identify renal vein compression. Following intervention, DU can successfully ensure patency of the renal vein stent with serial follow-up exams.
How Big is the Hole?
Authors: Alexander Thomas H. , Collins Lester B. , Harrison Preston E. , Woods Kathy
Published: March 2018

Transcranial Doppler (TCD) with agitated saline injection and transesophageal echocardiography (TEE) are used to evaluate cryptogenic stroke and transient ischemic attack (TIA) patients for patent foramen ovale (PFO). The role of the PFO may be to serve as a passageway for emboli from the peripheral venous system to the brain ( Figure 1 ). Alternatively, thrombi may form in situ at the PFO, especially with a concurrent atrial septal aneurysm. Blood coagulopathies can also contribute to clot formation. Clearly, the mere presence of a PFO cannot explain stroke in any given individual. Secondary stroke prevention includes anticoagulation or endovascular closure or both. Management controversies still exist. Regardless, sensitive and specific diagnostic procedures form the bedrock of our understanding. TCD is equal or superior in its sensitivity to the presence of any right-to-left shunt compared with echocardiography.1 Insurance carriers generally require a registered vascular technologist perform the technical portion of the TCD-PFO test.
Dialysis Access Steal Syndrome: The Severity Criteria Diagnosis with Arterial Doppler Examinations
Authors: Altawan Anita , Iljas John
Published: March 2018

Patients with dialysis access steal phenomenon can present with pain, paresthesia, ulceration, and tissue loss of the digits. Some degree of steal is common, up to 80% of patients with a radiocephalic arteriovenous fistula have mild, asymptomatic arterial steal documented by a decreased digital blood pressure. Critical ischemia of the upper extremity is a rare condition compared with ischemia of the lower extremities. High-flow arteriovenous fistulas have a greater risk of steal than normal flow arteriovenous fistulas; however, combined with arteriosclerotic disease they may also lead to ischemia. There are several strategies to prevent arterial steal following hemodialysis access that should be used; preoperative testing to identify proximal arterial lesions, upper extremity vein mapping and sizing, Allen's test (radial artery patency), end-to-side arteriovenous anastomosis to decrease steal and distal venous hypertension, selective venous arterialization at the elbow with ligation of deep perforation branch to improve maturation and restrict flow, and stepped or tapered grafts to limit flow. A noninvasive upper extremity arterial Doppler diagnosis is of importance to determine treatment options for patients. The goal of the vascular access surgeon is to promptly recognize and treat the disorder to maximize both limb and access salvage.
Accreditation is Perceived to Improve the Quality of Vascular Testing Facilities
Authors: Brinza Ellen K. , Zhu Linda J. , Lilly Michael , Manning Warren J. , Needleman Laurence , Gornik Heather L.
Published: March 2018

Objective

Accreditation for noninvasive vascular testing facilities has been available since 1990, but is not mandatory. We sought to determine the perceived value of accreditation among the staff of vascular laboratories accredited by the Intersocietal Accreditation Commission (IAC).

Methods

A multi-item electronic survey was sent to medical and technical staff and administrative contacts within the IAC database. Respondents were asked to rate statements about the impact of accreditation on their facility. Data for vascular testing facilities are presented.

Results

Of the 7,289 surveys sent, there were 882 (12.1%) respondents. Respondents were primarily responsible for the facility's accreditation application (75.0%), with the majority being technologists (82.0%), followed by physicians (11.3%). Most respondents were from hospital-based facilities (51.1%) and from facilities accredited for >3 years (79.6%). The majority, 94.3% of respondents, felt that maintaining accreditation of their facility was important (3.5% neutral, 2.2% not important). The greatest perceived benefits were in standardization of study acquisition and reporting, adherence to guidelines, and report completeness.

Conclusions

The majority of respondents from IAC-accredited vascular testing facilities viewed accreditation favorably. The favorable perception of accreditation by its users supports the value of accreditation for vascular testing facilities.
Comparison of Freehand 3D and 4D Ultrasound to Measure Thrombus Volume in Patients with Acute Deep Vein Thrombosis
Authors: Zhao Limin , Patel Richa , Sikdar Siddhartha , Prior Steven J.
Published: March 2018

Objectives

Current imaging techniques have limited ability to quantify thrombus burden in patients with acute deep vein thrombosis (DVT). There is limited ability to objectively measure clot progression or clot resolution over time and with treatment. These critical measures are important determinants of optimal treatment and therapeutic success for thrombolysis or thrombectomy treatment of DVT. In this study, we evaluated the feasibility and reliability of a method of quantifying thrombus volume using freehand three-dimensional (3D) ultrasonography and compared it to a commercially available four-dimensional (4D) transducer for acquiring and analyzing 3D ultrasound images to measure thrombus volume.

Methods

We studied 10 consecutive patients with a first episode of acute DVT to compare the performance of freehand 3D with 4D transducer imaging (group 1). In addition, we studied five patients with thrombus length >3.8 cm to evaluate the performance of freehand 3D imaging in larger clots (group 2). Scanning was performed with routine grayscale, color-flow, and power-Doppler imaging; followed by freehand 3D and 4D transducer volumetric imaging. Postprocessing was performed using the Stradwin software to measure thrombus volume after each scan.

Results

The age of patients was 54 ± 13 years (mean ± SD), 73.3% of DVTs were in the upper extremity, and 60% of the patients received anticoagulation. The mean thrombus volume in group 1 measured by freehand 3D and 4D probes was 0.49 ± 0.40 cm3 and 0.52 ± 0.46 cm3, respectively, and there was no significant difference between the measurements ( t = −1.57, p = 0.15). Regression analysis demonstrated good agreement between the two imaging modalities ( R2 = 0.99, regression slope = 1.13, p < 0.001). The freehand 3D technique was also successfully used to quantify thrombus volume (4.71 ± 3.28 cm3) in five patients with DVT >3.8 cm in length (group 2).

Conclusions

The described freehand 3D imaging protocol reliably measures thrombus volume in patients with acute DVT when compared with the commercially available 4D transducer. The freehand 3D method has the additional benefit of measuring thrombus volume in DVTs >3.8 cm in length. The method is convenient and can be used in clinical practice.
Incidental Finding of Adventitial Cystic Disease of the Common Femoral Vein: Case Report and Review of the Literature
Authors: Schaeffer Jacob S. , Davis Clark A. , Shakhnovich Irina
Published: March 2018

Adventitial cystic disease of the venous system is an uncommon pathology. The diagnostic workup, therapeutic options, and long-term outcomes are not well delineated. We present a case of a 37-year-old male who had an incidental finding of a cystic structure compressing his common femoral vein. Initially, the cyst was aspirated, but because of recurrence and new symptoms, the patient required surgical excision.
Ultrasound-Based Automated Carotid Lumen Diameter/Stenosis Measurement and its Validation System
Authors: Araki Tadashi , Kumar Asheed M. , Krishna Kumar P. , Gupta Ajay , Saba Luca , Rajan Jeny , Lavra Francesco , Sharma Aditya M. , Shafique Shoaib , Nicolaides Andrew , Laird John R. , Suri Jasjit S.
Published: March 2018

Objective

Degree of carotid stenosis is an important predictor to assess risk of stroke. Systolic velocity-based methods for lumen diameter and stenosis measurement are subjective. Image-based methods face a challenge because of low gradients in media and intima walls.

Methods

This article presents AtheroEdge™ 2.0, a two-stage process for automated carotid lumen diameter measurement that combats the above challenges. Stage one uses spectral analysis based on the hypothesis that far-wall adventitia is brightest. Stage two uses lumen pixel region identification based on the assumption that blood flow has constant density. Using global and local processing, lumen boundaries are detected. This clinical system outputs lumen diameter along with stenosis severity index (SSI).

Results

Our database consists of institutional review board–approved 202 patients (males/females: 155/47) left and right common carotid artery images (404 images, Toshiba scanner). Two trained neuro radiologists performed manual lumen border tracings using ImgTracer™ software. The coefficient of correlation between automated and two manual readings was 0.91 and 0.92. Dice similarity and Jaccard index were 95.82%, 95.72% and 92.10%, 91.92%, respectively. The mean diameter error between automated and two manual readings was 0.27 ± 0.26 and 0.26 ± 0.28 mm, respectively. Precision of merit was 98.05% and 99.03% with respect to two readings. SSI showed 97% accuracy.

Conclusions

The image-based automated carotid lumen diameter and stenosis measurement system is fast, accurate, and reliable.
Claudication, Tibial Neuropathy, and Peripheral Lymphedema after Total Knee Arthroplasty
Authors: Roberts J. G.
Published: March 2018

Vascular complications associated with orthopedic procedures, though rare, pose the potential for permanent disability or limb loss. Thermal, mechanical, and vibratory forces incurred during total knee arthroplasty may traumatize the popliteal artery leading to thrombosis, laceration, dissection, arteriovenous fistula, or pseudoaneurysm formation. Color duplex ultrasound (8 MHz), followed by digital subtraction angiography promptly diagnosed a large left popliteal artery pseudoaneurysm. Definitive surgical intervention via a posterior approach permitted direct arterial repair, venous decompression, and tibial neurolysis. There were no neurovascular sequelae. Adherence to both preoperative vascular assessment and meticulous surgical technique are crucial to mitigate against this potentially catastrophic injury.
Deep Vein Thrombosis Post Radiofrequency Ablation of the Saphenous and Perforator Veins: Is Duplex Ultrasound Necessary within Five Days?
Authors: Altawan Anita , Golchian David , Bazzi Mazen , Iljas John , Patel Bipinchandra
Published: March 2018

Radiofrequency ablation (RFA) of the saphenous and perforator veins (“closure”) is a relatively newer option for treatment of venous insufficiency patients. A known complication of the RFA is deep vein thrombosis also known as DVT. The purpose of this study is to demonstrate the probability of acute deep venous thrombosis post radio-frequency vein ablation. This research also helped determine medical necessity of a postoperative venous duplex examination within 5 days post-procedure.
Mycotic Aneurysm Detected by the Axiom: Scan Where the Pain Is
Authors: Baetz Laureen , Satiani Bhagwan
Published: March 2018

The lower extremity venous duplex scan is one of the most frequently ordered examinations in the vascular laboratory. Many laboratories will use the protocol format on the ultrasound machine to decrease time spent on examinations and increase productivity. The sonographer needs to be sure to obtain a thorough examination and not simply be led by the images to be acquired in the protocol setting. In addition, with more and more emphasis on sonographer productivity, it is tempting to do the test requested, move on to the next test, and let other professionals deal with the patient's symptoms. A recent interesting case in the vascular laboratory is used as an example of deviating from a strictly protocol-driven test to listening to the patient's complaints and scanning the symptomatic area.
Tumor Thrombus Arising from Osteosarcoma
Authors: Walder Emily , Usher Meredith L.
Published: March 2018

Tumor thrombus is a rare finding in patients diagnosed with osteosarcoma. A patient presented to our hospital with left knee pain and was diagnosed with osteosarcoma. Several months later, because of acute left foot swelling, a unilateral lower extremity venous duplex exam was performed and the patient was diagnosed with deep vein thrombosis (DVT). After further surgeries and tests, the previously diagnosed DVT was realized to be tumor thrombus. Although tumor thrombus mimics DVT on ultrasound, it is important to note subtle differences that may assist in making the correct diagnosis.
A compensation method based on extreme learning machine to enhance absolute position accuracy for aviation drilling robot
Authors: Yuan Peijiang , Chen Dongdong , Wang Tianmiao , Cao Shuangqian , Cai Ying , Xue Lei
Published: March 2018

To enhance the absolute position accuracy and solve complex modeling and computational complexity problems in traditional compensation methods for aviation drilling robots, a compensation method based on the extreme learning machine model was proposed in this article. The proposed method, in which the influence of geometric factors and the non-geometric factors of the robot is considered, builds a positional error prediction model based on extreme learning machine. As the input and output training data, the theoretical position and positional errors measured by a high-precision laser tracker were used to train and construct the extreme learning machine model. After the extreme learning machine model was constructed, the positional errors of prediction points could be predicted using the trained extreme learning machine. Then, the drilling robot controller could be directed to compensate for the predicted positional errors. To verify the correctness and effectiveness of the method, a series of experiments were performed with an aviation drilling robot. The experimental results showed that choosing an appropriate number of training points and hidden neurons for extreme learning machine could increase the computational efficiency without decreasing the high absolute position accuracy. The results also show that the average and maximum absolute position accuracy of robot tool center point were improved by 75.89% and 80.93%, respectively.
Modeling and control of two-link snake
Authors: Lipták Tomáš , Virgala Ivan , Miková L’ubica , Galajdová Alena , Tuleja Peter , Koukolová Lucia , Varga Jozef , Sukop Marek
Published: March 2018

This article deals with using of geometric mechanics at modeling mixed mechanical locomotion systems. In introductory part, the division of locomotion systems and reduced motion equation, which create the mathematical model of the system, is analyzed. Further we devoted to example of mixed locomotion system—two-link snake. We created the mathematical model of this example, simulated this system, and represented other tools of geometric mechanics.
Correspondence matching among stereo images with object flow and minimum spanning tree aggregation
Authors: Zhang Jinglin , Liu Zhiwei , Nezan Jean-Francois , Zhang Guoyu
Published: March 2018

Stereoscopic correspondence matching is applied in many applications like robot navigation, automatic driving, virtual, and augmented reality by reconstructing the scene in three-dimensional environments. In the most real scenes, the moving objects attract more attentions than static objects and background. Thus, temporal information of consecutive frames like motion flow has been proven to improve the matching accuracy as weight prior. In this article, we propose a cost-aggregation method joining object flow and minimum spanning tree-based support region rather than aggregating on fixed size windows. However, directly combining object flow and minimum spanning tree filtering is not straightforward, due to the extremely high computing complexity. The proposed scheme implements nonlocal cost aggregation with object-based optical flow, which extends the idea of the minimum spanning tree and flow-based motion estimation to increase the matching accuracy. Temporal evidence of object flow is not only used in minimum spanning tree support region building but also incorporated with one hybrid edge prior to optimize the disparity estimation. The experimental results with synthetic stereo videos show that the proposed method outperforms other state-of-the-art stereo matching methods in most data sets. The whole stereo correspondence algorithm achieves competitive performance in terms of both accuracy and speed. We also illustrate the performance of the proposed method with the Karlsruhe Institute of Technology and Toyota Technological Institute (KITTI) benchmark as one extensive comparison.
Modeling of Bernoulli gripping device orientation when manipulating objects along the arc
Authors: Savkiv Volodymyr , Mykhailyshyn Roman , Duchon Frantisek , Mikhalishin Mykhailo
Published: March 2018

The objective is to define optimal orientation of gripping device with minimal gripper energy consumption, having preset parameters of manipulator, Bernoulli device, object of manipulation and its path. The division of the arc into three sections—speed-up, steady motion, slowing-down—is presented. The optimal orientation is defined in any point of time on each section, which is defined using inertial and gravity forces as object of manipulation retention force with gripping device. Problem solution for a specific example, providing continuous transportation along the whole path for the object of manipulation, is introduced. The effectiveness of using this method of object transportation along the arc is proved. The energy efficiency of the implementation of the optimization orientation method was 41% for the example given.
Sinthasomphone: A Case Study of Legal Discourse’s Inability and Refusal to Hear Intersectional Injustice
Authors: Vafai Sohayl
Published: March 2018

This article uses the Sinthasomphone opinions to argue that courts are generally unable to or, otherwise, refuse to hear intersectional injustice. Fittingly, Kimberlé Crenshaw coined “intersectionality” in her article, “Demarginalizing the Intersection of Race and Sex: A Black Feminist Critique of Antidiscrimination Doctrine, Feminist Theory and Antiracist Politics,” only a few years before the Sinthasomphone opinions were issued. Her article served, and continues to serve, as a chilling reminder of the need for legal discourse to develop intersectional theory. This article builds on Crenshaw’s initial argument and stresses the need for legal actors to lean into their discomfort in cases involving non-normative identities. Although the opinions in Sinthasomphone were issued almost thirty years ago, courts have progressed little in their analyses of similar cases. The Sinthasomphone opinions are also an appropriate case study given the notoriety of Jeffrey Dahmer and the public’s familiarity with Sinthasomphone’s killing.
Can gay and lesbian educators form authentic relationships in their school communities?
Authors: Hooker Steven D
Published: March 2018

The purpose of this study was to determine how gay and lesbian teachers who are out or closeted form and maintain relationships with members of their school community. A total of 11 gay and lesbian public and Catholic school educators from rural, suburban, and urban schools were interviewed. Each of these educators negotiated their sexual identities differently within their school communities, allowing them to form or not form relationships with colleagues, students, and parents. Descriptors such as age, experience level, and school setting, however, did not affect how open they were to establish authentic relationships with others in their schools. Most of these educators were unable to negotiate their sexual identity with their teacher identity due to fear of being authentic due to possible harassment and even being fired, keeping them from forming any meaningful relationships in their workplace settings. This study does, however, have strong implications toward developing policies that are inclusive for all lesbian and gay members of the school community.
How many single-nucleotide polymorphisms (SNPs) must be tested in order to prove susceptibility to bacterial meningitis in children? Analysis of 11 SNPs in seven genes involved in the immune response and their effect on the susceptibility to bacterial meningitis in children
Authors: Gowin Ewelina , Świątek-Kościelna Bogna , Kałużna Ewelina , Strauss Ewa , Wysocki Jacek , Nowak Jerzy , Michalak Michał , Januszkiewicz-Lewandowska Danuta
Published: March 2018

The aim of this study is to describe the prevalence of single single-nucleotide polymorphisms (SNPs) as well as their combinations in genes encoding proteins involved in the immune response in children with bacterial meningitis. The prospective study group consisted of 39 children with bacterial meningitis and 49 family members surveyed between 2012 and 2016. Eleven SNPs in seven genes involved in immune response were analysed. The mean number of minor frequency alleles (MAF) of studied SNPs was lowest in the control group and highest in patients with pneumococcal meningitis. We found that carrying ≥6 MAF of studied SNPs was associated with an increased risk of pneumococcal meningitis. The prevalence of risky variants was noted to be higher in patients with pneumococcal meningitis as compared to the control group. In conclusion, genetic factors are a relevant factor in determining the susceptibility to bacterial meningitis. A statistically significant cumulative effect of mutated variants on increasing the risk of bacterial meningitis was detected. Combining all three SNPs in MBL2 improves the prediction of susceptibility to pneumococcal meningitis. Analysis of risky alleles can help indicate people prone to the disease who are ‘gene-immunocompromised’.
Visceral fat mass as a novel risk factor for predicting gestational diabetes in obese pregnant women
Authors: Balani J , Hyer SL , Shehata H , Mohareb F
Published: March 2018

Objective

To develop a model to predict gestational diabetes mellitus incorporating classical and a novel risk factor, visceral fat mass.

Methods

Three hundred two obese non-diabetic pregnant women underwent body composition analysis at booking by bioimpedance analysis. Of this cohort, 72 (24%) developed gestational diabetes mellitus. Principal component analysis was initially performed to identify possible clustering of the gestational diabetes mellitus and non-GDM groups. A machine learning algorithm was then applied to develop a GDM predictive model utilising random forest and decision tree modelling.

Results

The predictive model was trained on 227 samples and validated using an independent testing subset of 75 samples where the model achieved a validation prediction accuracy of 77.53%. According to the decision tree developed, visceral fat mass emerged as the most important variable in determining the risk of gestational diabetes mellitus.

Conclusions

We present a model incorporating visceral fat mass, which is a novel risk factor in predicting gestational diabetes mellitus in obese pregnant women.
School Nurses on the Front Lines of Medicine: The Approach to a Student After a Syncopal Event: Don’t “PASS OUT”
Authors: Hackett Gretchen , Brady Jodi , Olympia Robert P.
Published: March 2018

Students presenting with syncope and/or seizure occur occasionally in the school setting. Several studies have shown that seizures as well as respiratory distress are the most common medical emergencies that prompt school nurses and staff to contact emergency medical services (EMS) to transport students to the closest emergency department (Knight 1999, Olympia 2005). It is important to develop a differential diagnosis for syncope, to initiate stabilization of the student with life-threatening symptoms, and to triage these students to an appropriate level of care (back to the classroom, home with their guardian with follow-up at their primary health care provider’s office, or directly to the closest emergency department via EMS). This article describes the initial assessment and management of two students presenting after syncopal events.
Addressing the selectivity and toxicity of antiviral nucleosides
Authors: Feng Joy Y
Published: March 2018

Nucleoside and nucleotide analogs have played significant roles in antiviral therapies and are valued for their impressive potency and high barrier to resistance. They have been approved for treatment of herpes simplex virus-1, HIV, HBV, HCV, and influenza, and new drugs are being developed for the treatment of RSV, Ebola, coronavirus MERS, and other emerging viruses. However, this class of compounds has also experienced a high attrition rate in clinical trials due to toxicity. In this review, we discuss the utility of different biochemical and cell-based assays and provide recommendations for assessing toxicity liability before entering animal toxicity studies.
Categorisation of Colour Terms Using New Validation Tools: A Case Study and Implications
Authors: Arbab Shabnam , Brindle Jonathan A. , Matusiak Barbara S. , Klöckner Christian A.
Published: March 2018

This article elaborates on the results of a field experiment conducted among speakers of the Chakali language, spoken in northern Ghana. In the original study, the Color-aid Corporation Chart was used to perform the focal task in which consultants were asked to point at a single colour tile on the chart. However, data from the focal task could not be analysed since the Color-aid tiles had not yet been converted into numerical values set forth by the Commission internationale de l’éclairage (CIE). In this study, the full set of 314 Color-aid tiles were measured for chromaticity and converted into the CIE values at the Daylight Laboratory of the Norwegian University of Science and Technology. This article presents the conversion methodology and makes the results of the measurements, which are available in the Online Appendix. We argue that some visual-perception terms cannot be reliably ascribed to colour categories established by the Color-aid Corporation. This suggests that the ideophonic expressions in the dataset do not denote ‘colours’, as categorised in the Color-aid system, as it was impossible to average the consultants’ data into a CIE chromaticity diagram, illustrate the phenomena on the Natural Colour System (NCS) Circle and Triangle diagrams, and conduct a statistical analysis. One of the implications of this study is that a line between a visual-perception term and a colour term could be systematically established using a method with predefined categorical thresholds.