bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential for Significantly Overestimating Doppler Velocity Measurements in Angulated Internal Carotid Arteries
Authors: Scissons Robert P. , Hoskins Megan S. , Kimball Robyn 
Published: March 2018

Purpose Carotid artery tortuosity presents significant technical challenges in angle correction and cursor alignment. Although these spectral Doppler issues have been known to hinder carotid ultrasound accuracy, the potential for these errors is generally unknown. We evaluated angle correction and velocity measurements in patients with insignificant internal carotid artery (ICA) disease and angulated vessels. Methods Data from assenting patients with ICA tortuosity and insignificant (<50% diameter reduction) disease were prospectively entered into a database during a 15-month period. Only initial duplex examinations were included in this study. Tortuosity was defined as an ICA “S”-shaped curvature with at least one area of <90-degree angulation. Eight peak systolic velocity (PSV) measurements were performed, the first immediately before the first bend in the S-curvature (V1), the second at the 60-degree angle at the apex of the first curvature (V2), the third at the 0° angle at the apex of the first curvature (V3), the fourth at the first curvature apex and angle corrected to the inside wall after the curvature (V4), the fifth at the 60-degree angle at the apex of the second bend in the S-curvature (V5), the sixth at the zero-degree angle at the apex of the second curvature (V6), the seventh at the second curvature apex and angle corrected to the inside wall after the second curvature (V7), and the eighth after the second bend in the S-curvature (V8). Insignificant ICA disease was defined by PSV of <125 cm/sec. Results A total of 47 patients and 56 vessels were analyzed. Mean PSV (cm/sec) and standard deviation (SD) for the eight PSV measurements were as follows: 76.4/20.0 (V1), 137.8/37.8 (V2), 67.5/18.6 (V3), 86.7/24.8 (V4), 138.8/37.6 (V5), 66.2/17.6 (V6), 91.1/25.6 (V7), and 77.0/19.9 (V8). All PSV measurements were less than 125 cm/sec at the apex of the curvature when we used a zero-degree Doppler angle of incidence (V3 and V6). A minority of velocities were overestimated when angle corrected to the inside walls of the first and second bend, 7% (V4) and 11% (V7), respectively. The majority of V2 (71%) and V5 (70%) PSV measurements were significantly overestimated. Conclusions The use of a 60-degree Doppler angle of incidence at the apex of tortuous ICA vessels resulted in significant overestimations of PSV in ≥70% of all vessels analyzed. Spectral analysis within this area should be standardized at zero degrees to minimize false positive impressions of hemodynamically significant carotid occlusive disease.
Iliac Artery Endofibrosis in Athletes: A Case Series
Authors: Smith Watson B. , Olmsted Kari A. , Zierler R. Eugene 
Published: March 2018

Introduction Endofibrosis of the external iliac arteries (IE) occurs in some high-performance athletes, particularly female cyclists, and causes leg pain on extreme exertion. Establishing the diagnosis in these cases is challenging, because a vascular cause is often not suspected initially. The anatomic lesion of IE is difficult to detect with B-mode ultrasound because of the characteristic smooth and diffuse thickening of the arterial wall. Standard treadmill testing can be equivocal in these athletes, but more intense or “extended” treadmill exercise can demonstrate the physiological abnormalities. Case Report This report describes our experience with 6 limbs of 4 patients found to have IE and who also underwent surgical intervention to relieve symptoms. All patients had normal resting ankle/brachial indices, except one, who also had iliac artery thrombosis. Duplex scanning showed diffusely increased velocities throughout external iliac segments. The treadmill exam was modified, with speeds ranging from 2.5 to 5.8 mph and exercise times up to 15 minutes required to provoke a significant decrease in ankle pressure. Monophasic, high-velocity postexercise Doppler flow waveforms helped to localize the site of the responsible lesions. Results All 6 limbs were treated by enlarging the affected external iliac artery with a vein patch angioplasty (thrombectomy was also performed in one patient). Inspection of the arterial lumen at surgery revealed a smooth, fibrous-appearing lesion with diffuse wall thickening. The 5 limbs, which had postoperative treadmill tests, all had normal results and these patients resumed athletic training. Among 5 limbs with postoperative duplex scans, 2 showed normal vessel diameter, and 3 had a dilated lumen. Conclusion Although the mechanism of IE is not known, the typical history and location of the lesions suggests that repetitive stress or bending of the vessels and high flow during extreme exercise leads to thickening of the arterial wall. Awareness of this entity and a modified vascular testing protocol are essential to establishing the diagnosis.
Reproducibility of Toe Pressure Measurements
Authors: Cloete Neil , Kiely Clare , Colgan Mary Paula , Haider Naseem , O'Neill Sean , Madhavan Prakash , Moore Dermot 
Published: March 2018

Introduction Ankle/brachial indices are inaccurate in the presence of calcification, and physicians may rely on the measurement of digital pressures. As the population continues to age and with the escalation in type 2 diabetes, the importance of, and reliance on, toe pressure measurements will increase. The aim of this study was to assess the reproducibility of toe pressure measurements in a single vascular laboratory. Methods Repeated ankle/brachial indices and toe pressures were measured in 20 patients (10 with known peripheral vascular disease and 10 with aneurysmal or carotid artery disease but no history of PVD), and 10 control patients. Three measurements were made 48 hours apart. All measurements were made by a single vascular technologist. Reproducibility was assessed by the use of the repeatability coefficient and the intraclass correlation coefficient. Results Ankle/brachial indices ranged from 0.36 to 2.4, toe pressures from 18 mmHg to 173 mmHg, and toe/brachial indices from 0.11 to 1.1. The repeatability coefficient showed no significant difference between measurements ( p > 0.1) and the intraclass correlation coefficient estimates showed high agreement between repeated measurements (0.77–0.99). Bland-Altman plots indicated that the observer variability was equally distributed across the range of pressure measurements. Conclusion These results confirm the intraobserver reproducibility of toe pressure measurements; however, further work is required to demonstrate inter-observer reproducibility.
Technical Aspects of Duplex Ultrasound-Guided Angioplasty of Arteriovenous Fistulae
Authors: Wang John , Blebea John , Kennedy Tara , Salvatore Michael , Kelly Patrick 
Published: March 2018

Introduction Up to one-third of autologous arteriovenous fistulae (AVF) created for hemodialysis access will require additional interventions to maintain patency or promote maturation. We describe the technical aspects of duplex ultrasound-guided AVF angioplasty as an alternative to traditional contrast fistulogram and angioplasty. Methods The procedure can be performed either in the operating room, interventional procedures suite, or in an outpatient office setting. It is done in a sterile fashion under local anesthesia and light intravenous sedation. With the use of a 12-MHz linear probe and color Doppler imaging, the AVF is surveyed in both the longitudinal and transverse planes, with velocity measurements for identification of areas of stenosis and measurement of AVF blood flow to examine for failure of maturation. Specific areas of stenosis are marked with a skin marker. Percutaneous access into the AVF, guidewire advancement, angioplasty balloon inflation, and deflation are all performed under direct ultrasound visualization. Successful angioplasty is achieved when the vessel diameter, flow, and velocity improve to acceptable ranges. Results We have found that duplex ultrasound provides accurate diagnosis of AVF stenosis and non-maturation. Ultrasound information assisted us in the selection of angioplasty balloon sizes and the process of balloon inflation-deflation. Available real-time hemodynamic assessment of lesions before and after interventions provided immediate feedback on the efficacy of treatment. Additional information such as vessel wall recoil, residual stenosis, or plaque dissection after angioplasty guided the upsizing of balloons or deployment of intravascular stents. Conclusions Duplex ultrasonography offers the potential for a less expensive and more informative treatment of stenotic or non-maturing arteriovenous fistulas in a variety of outpatient settings. One such future potential location includes the Vascular Laboratory. It offers additional benefits of the avoidance of ionizing radiation and nephrotoxic contrast.
Risk Focused Screening for Vascular Disease: One University Hospital's Experience
Authors: Hughes Joseph P. , Dubin Rick , Rodriguez-Wong Angela , Porreca Francis J. 
Published: March 2018

Introduction Vascular screening programs have been gaining popularity in recent years; however, most programs accept all patients willing to participate. This study was designed to determine the yield of disease when screening examinations are limited to those most at risk, to stratify the amount of disease present in the at-risk population, and to establish which patients might benefit most from vascular screening. Materials and Methods Patients enrolled in a community outreach program for seniors 55 years of age and older were asked to participate in a free vascular screening. Screenings consisted of completion of a questionnaire, physical examination, limited carotid artery evaluation for stenosis, aorta evaluation for detection of aneurysm, and ankle/brachial index (ABI) calculation to detect peripheral vascular disease. Findings were grouped into “Normal,” “Mild disease,” and “Significant disease.” Findings were then compared with the following controllable risk factors: hypertension, hyperlipidemia, diabetes, coronary artery disease (CAD), or smoking history. Results Between May 16 and October 17, 2007, 357 participants' (75 male, 157 female, mean age 72.9 years) results were analyzed. Overall, 140 participants (43%) had some form of vascular disease (“mild” and “significant” categories combined). Of 324 eligible participants, carotid findings showed 199 normal (61%), 104 mild (32%), and 21 significant (7%) results. Aorta findings showed 296 normal (91%), 25 mild (8%), and 3 significant (1%) results. ABI findings showed 278 normal (86%), 18 mild (6%), and 28 significant (8%) results. In participants with three or more risk factors, there was a greater probability that carotid ( p = 0.0022) and peripheral vascular disease ( p = 0.0003) would be detected; however, there was no predictive value for aortic aneurysm ( p = 0.5). Conclusion Vascular screening programs focusing on the at-risk population may reduce unnecessary testing compared with programs evaluating all patients willing to participate.
Dynamic Internal Carotid Artery Dissection Demonstrated by Carotid Duplex Ultrasound
Authors: Mady Ehab N. , MacDonald Kate , Sila Cathy A. , Gornik Heather L. 
Published: March 2018

Background Carotid artery dissection is an important cause of stroke in young adults. Because warning signs usually precede stroke, the timely diagnosis of carotid dissection can have a significant clinical impact. We present a case of spontaneous carotid artery dissection with dynamic findings on duplex ultrasound examination. Case Report A 47-year-old man presented with acute neurologic symptoms. Carotid duplex ultrasound demonstrated a high resistive waveform in the right internal carotid artery (RICA) with absent end-diastolic flow (peak-systolic velocity [PSV] = 49 cm/sec, end-diastolic velocity = 0 cm/sec), a narrowing of the lumen in the distal RICA with low velocity flow (PSV = 10 cm/sec), and eventual loss of flow. The right common carotid artery demonstrated a high resistive waveform. The use of magnetic resonance angiography confirmed the presence of distal RICA dissection. The patient was treated with antiplatelet therapy and had marked clinical improvement within 48 hours. A duplex ultrasound study performed 24 hours after the first study demonstrated dramatic restoration of the diastolic flow in the RICA (PSV = 97 cm/sec, EDV = 44 cm/sec) with normalization of the Doppler waveforms. Repeat magnetic resonance angiography demonstrated near complete resolution of the RICA dissection, correlating with the ultrasound findings. Conclusion Our case demonstrates the potentially dynamic nature of carotid artery dissection and the utility of duplex ultrasound as an invaluable tool in the early diagnosis and management of this disorder. In addition, the case demonstrates the importance of carotid Doppler waveform clues as indirect evidence of more distal cerebrovascular disease that warrants further investigation.
Possible Associations between Scan Quality and Pain during Ultrasound Scanning: Results from the Society for Vascular Ultrasound 2009 Survey on Ergonomics
Authors: Polak Joseph F. , Baker Joan , Jones Anne , Haracznak Steve , Harrington Anita 
Published: March 2018

Background Pain might act as a distraction while the operator performs ultrasound imaging. It is not clear whether perceived pain while scanning is associated with scan quality. Materials and Methods An internet-based survey was conducted during the months of April to June 2009 for members of the Society for Vascular Ultrasound (SVU). Survey questions included questions evaluating demographics, work load, practice milieu, and level of imaging experience. The level of pain experienced while performing scans in the last month before the survey was evaluated on a pain scale of 0 to 10 and the possibility that scan quality might have been affected (0 no effect, 1, possibly and 2, definitely). Comparisons were made with the use of analysis of variance and multivariable logistic regression. Results We evaluated the responses of 640 SVU members for a response rate of 14.4%. Most sonographers surveyed were in the 50 years or older age category (n = 296; 46.6%) and had an average of 21 or more years of imaging experience (n = 257; 41%). We found that scan quality was inversely associated with the level of experienced pain ( p < 0.0016) and positively associated with transducer time: as pain and transducer time increased, scan quality decreased taking into consideration age, gender, and experience. Conclusion Our data suggest that pain while scanning and sonographer perception that quality of the examination is affected are strongly associated. Further analyses of the survey data and the development of appropriate analytical tools are needed to investigate possible causal links.
Carotid Duplex Imaging on a Patient with a Temporary Left Ventricular Assist Device
Authors: Blasingame Nancy , Lewis Tammy , H'Doubler Peter B. , Zarge Joseph I. , Jansen Donald E. 
Published: March 2018

Introduction In a carotid Duplex scan, the spectral Doppler examination is used to quantify stenosis by using the peak systolic and end diastolic velocities and ratios of the systolic velocities. The carotid spectral waveform is markedly different when a patient has a temporary left ventricular assist device (LVAD) that is nonpulsatile or continuous because of the oxygenated blood being redirected from the left atrium into the femoral artery via a centrifugal pump. This continuous-flow device provides complete circulatory support, preserving organ function and allowing quick restoration of hemodynamic stability. Case Report A 23-year-old man with idiopathic dilated cardiomyopathy, end-stage congestive heart failure, and cardiogenic shock required emergent placement of a TandemHeart temporary LVAD. Carotid Duplex imaging was performed the next day as a routine examination ordered for preheart transplant evaluation. No atherosclerotic disease was noted on B-mode images; however, intermittent bubbles were visualized and appeared as high-intensity transient signals within the Doppler spectral waveform. Flow was continuous in the carotid and vertebral arteries bilaterally. Discussion Percutaneous LVAD devices are increasingly being used as a short-term “bridge to cardiac transplantation.” Vascular sonographers should be aware that peripheral arterial flow will be nonpulsatile in patients who are sustained on these continuous flow devices. If significant disease is present we will need to rely on B-mode and color images and calculation of percent area or diameter reduction instead of waveform and velocity data.
Carotid Artery Restenosis: Ultrasonographic Characteristics
Authors: Maia Miguel , Ferreira Joana , Braga Sandrina , Vasconcelos João , Brandão Pedro , Vaz Guedes 
Published: March 2018

Introduction The purpose of our study was to evaluate the ultrasonographic characteristics of recurrent carotid stenosis in patients submitted to carotid endarterectomy with patch angioplasty. Methods We performed carotid ultrasound examinations on patients who had undergone unilateral carotid endarterectomy between 2002 and 2009. Patients with bilateral and/or endovascular procedures were excluded. All ultrasound examinations were performed by the same registered vascular technologist. Results One hundred male and 25 female patients were studied. The average time between surgery and the ultrasound examination was 38.8 months (range, 3–99.2 months). Twenty-nine (23.2%) patients had recurrent carotid artery stenosis after unilateral endarterectomy. Of these, 17 patients were found to have recurrent carotid artery stenosis classified as <50%; 7 patients had recurrent stenosis in the range of 50% and 69%, and 5 patients had >70% diameter-reducing lesions. Plaques associated with recurrent carotid stenosis were significantly less echogenic, more acoustically homogenous, and had a smoother surface contour. Compared with the primary carotid stenosis (nonintervened side), plaques associated with recurrent carotid stenosis were more often hypoechoic (58.6% versus 8.1%), acoustically homogenous (69% versus 44.6%) and smooth-surfaced (93.1% versus 74.3%). Also, the longer the interval between surgery and the carotid sonographic examination, the more similar the ultrasonographic characteristics were between the two groups. Conclusions The different sonographic characteristics of primary carotid stenosis and recurrent stenosis after carotid endarterectomy in the same patients, are associated with different outcomes for the two conditions. There is a current clinical consensus that patients presenting with recurrent symptoms after carotid endarterectomy should be treated, but the best management for asymptomatic patients with recurrent carotid artery stenosis remains uncertain.
Carotid Intima-Media Thickness and Plaque Morphology in Carotid Stent Patients over Time
Authors: Daly Courtney M. , Davis Julia T. , Woo Edward Y. , Jackson Benjamin M. , Fairman Ronald M. , Mohler Emile R. , Wang Grace J. 
Published: March 2018

Introduction Carotid intima-media thickness (CIMT) is a well-known correlate of atherosclerotic disease. CIMT has not been studied in patients who have undergone carotid artery stenting. We sought to determine the effects of carotid artery stenting on common carotid artery (CCA) CIMT as well as carotid plaque morphology over time. Methods This was a retrospective chart review of 20 patients at the investigating institution. Demographic and clinical data were recorded. Gray scale B-mode images were used to perform measurements of CCA CIMT at three different locations in the stented as well as nonstented CCA by two independent observers. Mean values were calculated, and the CIMT of the stented side was compared with its control at each time point. Studies were performed preoperatively, at 1 month, 3 months, 6 months, 12 months, and 24 months postoperatively. Characterization of plaque morphology was also made at each time point. Results There were 7 female and 13 male participants. CIMT initially decreased on the stented side at 3 months but showed an increase during a 24-month period that was statistically different from the control group ( p > 0.031). Female participants demonstrated a smaller CIMT at each time point compared with male participants with a relatively stable CIMT whereas male participants demonstrated an increase in CIMT over time. A history of diabetes, smoking, statin use, or angiotensin-converting enzyme inhibitor use did not appear to affect CIMT. Characterization of carotid plaque morphology demonstrated that the majority of plaques were heterogeneous in nature and became more homogeneous after stenting. Conclusions CIMT of the CCA increases after carotid stenting. Interestingly, female participants exhibit a smaller CIMT that is not subject to change over time. The majority of plaques was heterogeneous in nature and became more stable over time. These findings lend insight into patterns of vessel wall healing after angioplasty and stenting.
Isolated Dissection of the Superior Mesenteric Artery with Associated Median Arcuate Ligament Compression of the Celiac Artery in an Asymptomatic Patient
Authors: Bille Travis , Gabriel Joy , Chandran George 
Published: March 2018

Introduction A 45-year-old man presented to the vascular laboratory for evaluation of an abdominal bruit and was found to have a superior mesenteric artery (SMA) dissection in conjunction with median arcuate ligament syndrome. This case study details the course of his evaluation and the importance of thorough examination in ultrasound exams. Methods A duplex ultrasound exam was performed with an ATL HDI 3500 sonographic unit with a 5.2 MHz curvilinear transducer. Results A 45-year-old asymptomatic white man reported to his physician for a routine physical. During the examination, the physician heard an abdominal bruit and referred the patient to the vascular lab for a mesenteric duplex ultrasound. The duplex ultrasound showed chronic dissection of the SMA with severe narrowing in the true lumen, and the celiac artery Doppler showed classic velocity increase with respiratory variation consistent with Median Arcuate Ligament Syndrome. A computed tomography angiogram later confirmed the diagnosis. Conclusion Isolated SMA dissection is an exceedingly rare condition that has only been reported 55 times in literature. Median arcuate ligament syndrome occurs more frequently, but its presence in conjunction with SMA dissection has only been reported in literature once. Undiagnosed SMA dissection can lead to bowel necrosis, mesenteric ischemia, or death. The careful attention by the referring physician to an abdominal bruit and the prompt use of Duplex ultrasound facilitated the discovery of a rare, serious, and potentially fatal dissection of the SMA, as well as median arcuate ligament syndrome.