bluuebunny/crossref_metadata_2025 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.
Expansion of the SAAAVE Protocol with Addition of Ultrasound Scans of the Femoral and Carotid Arteries to Prevent Heart Attacks and Strokes
Authors: Lavenson George S.
Published: March 2018

Introduction

Heart attacks and strokes are the leading cause of death and disability. Most occur without warning. To prevent heart attacks and strokes in seniors, in this article I propose an expanded SAAAVE program that includes an ultrasound scan of the carotid and femoral artery along with that of the aorta. A positive scan of any of these would trigger a metabolic and cardiac evaluation, allowing early management of systemic arteriosclerosis and preemptive intervention for critical disease of the coronary artery as well as the carotid artery and aorta.

Method

The carotid artery, femoral artery, and aorta are rapidly scanned. Positive studies are referred for full follow-up examinations and metabolic/cardiac evaluations. Medicare does cover some aortic scans and the indicated follow-up tests and care that result from all scans.

Results

Medical and interventional management can prevent fatal heart attacks from known coronary artery disease. Intervention for significant carotid disease that is present in 7.5% of seniors could prevent more than 200,000 strokes and save nearly 13 billion dollars annually. Screening for abdominal aortic aneurysm has decreased deaths from ruptured aneurysms, and statin therapy for dyslipidemia can reduce future cardiac events.

Conclusions

This simple, rapid, one-stop screen for seniors has the potential to prevent death and disability from heart attack, stroke, and ruptured abdominal aortic aneurysm
Case Study of Idiopathic Retroperitoneal Fibrosis
Authors: Hannon Kathleen , Jaff Michael R.
Published: March 2018

We report an abdominal aortic duplex case with an uncommon presentation of idiopathic retroperitoneal fibrosis that was confirmed by periaortic inflammatory tissue biopsy. This case was an excellent presentation of how, with an increased awareness by the sonographer, the choice of transducer can have an effect on subtle pathology changes, such as inflammatory tissue, on ultrasound examinations.
Importance of Phasicity in Detection of Proximal Iliac Vein Thrombosis with Venous Duplex Examination
Authors: Sanford Deborah A. , Kelly Donna , Rhee Soo J. , Stoughton Julianne , Cantelmo Nancy L.
Published: March 2018

Superficial venous reflux is commonly the cause of symptomatic venous disease, but proximal venous obstruction may also play a role. A duplex ultrasound evaluating bilateral common femoral veins can detect differences in phasicity, which may be due to pelvic venous obstruction. We report a case of a patient with recurrent symptomatic varicose veins after treatment of superficial venous reflux. Based the duplex ultrasound results of damped respiratory phasicity, the patient was diagnosed with deep venous obstruction which was confirmed on MRV.
Application of Duplex Ultrasonography in the Midaortic Syndrome
Authors: Wilson Stephanie , Atnip Robert , Turner Tricia , Wilson Ryan
Published: March 2018

Objective

Midaortic syndrome is a rare condition found primarily in children that causes stenosis of the abdominal aorta and its proximal branches. Duplex interpretation criteria derived from adults do not necessarily apply to the pediatric population but are sometimes used empirically in specific cases. We report the case of a 5-year-old girl whose aorta and renal arteries were studied by duplex ultrasound, with anatomic and radiologic correlation.

Case Report

The patient was a 5-year-old girl with refractory hypertension on multiple antihypertensive medications. Her initial diagnosis of midaortic syndrome was made via duplex ultrasound. The findings were confirmed by angiography and showed smooth narrowing of the mid- to distal abdominal aorta with concomitant bilateral renal artery origin stenosis. Surgical repair of the aorta was performed with the use of a patch angioplasty technique with pulmonary artery homograft. The left renal artery was re-implanted onto the infrarenal aorta and an aorta to right renal artery bypass graft was placed using autogenous left internal iliac artery. Duplex ultrasound was then used to evaluate the success of the surgical repair.

Conclusion

Duplex ultrasound proved effective in the preoperative and postoperative care of this small child with midaortic syndrome and renal artery stenosis. The standard adult criteria for renal artery stenosis can be used selectively in children to assist in the diagnosis of unusual vascular conditions.
Continuous-Wave Doppler Ultrasound
Authors: Cardullo Paul A.
Published: March 2018

Early noninvasive vascular diagnostic procedures relied heavily on continuous-wave (CW) Doppler ultrasound techniques. Development of CW Doppler instrumentation began in the mid 1950's in Japan with the work of physicist Shigeo Satomura. Donald Baker, an engineer at the University of Washington, working under the direction of pediatric cardiologist Robert F. Rushmer, lead a team that developed the first CW Doppler instrument in the United States in the early 1960's. CW Doppler instruments use two elements to continuously transmit ultrasound waves and to receive signals from moving reflectors within the ultrasound field. CW instruments are less costly and electronically less complex than pulsed Doppler systems. The major disadvantage of CW Doppler is the absence of depth discrimination. Display options include simple “audio” interpretation, analog recordings produced by a zero crossing detector, and spectral Doppler waveforms using fast Fourier analysis. Despite the limitations of CW Doppler techniques, they remain popular today in the assessment of patients in various clinical settings.
Principles of Spectral Doppler
Authors: Kremkau Frederick W.
Published: March 2018

Spectral-Doppler ultrasound provides a quantitative visual presentation of blood-flow information. The spectral display is a real-time presentation of Doppler shift vs. time on the vertical and horizontal display axes, respectively. The vertical axis is normally calibrated in flow-speed units by solving the Doppler equation with Doppler angle incorporation (by the instrument operator). The spectral display provides flow information (presence, direction, speed, character) at the site of observation (sample volume location). Information regarding proximal and distal flow conditions can also be derived from the spectral display. Pulsed wave Doppler systems provide the ability to select the depth from which Doppler information is received. Spectral analysis provides visual information on the distribution (spectrum) of Doppler-shift frequencies resulting from the distribution of scatterer velocities (speeds and directions) encountered within the sample volume. The spectrum is derived electronically using the fast Fourier transform and is presented on the display as Doppler shift versus time, with brightness or color indicating the strength of the Doppler shifts. Flow conditions at the site of measurement are indicated by the (vertical) width of the spectrum, with spectral broadening indicative of disturbed and turbulent flow. Flow conditions downstream, especially distal flow impedance, are indicated by the relationship between peak systolic and end-diastolic flow speeds. Proximal stenosis is indicated by the tardusparvus waveform. Aliasing displaces systolic Doppler shifts to the wrong side of the baseline when the Nyquist limit is exceeded. Aliasing is corrected by baseline shifting and, in extreme cases, scale change, which increases the sampling rate (PRF).
Cardiac Effects on Peripheral Vascular Doppler Waveforms
Authors: Bendick Phillip J.
Published: March 2018

In the aging patient population seen routinely in the noninvasive vascular laboratory, the possibility of Doppler waveform abnormalities secondary to cardiac effects, rather than localized obstructive disease, should be kept in mind. These abnormalities present in a variety of ways in both the arterial and venous systems, but they tend to follow two general rules. First, cardiac effects are systemic; for example, on the arterial side the carotid arteries, aorta and femoral arteries would all be affected to some degree. Second, cardiac effects are bilateral; thus, if an abnormality is only seen in one carotid artery, it is likely a carotid problem. If the same abnormality is seen in both carotid arterial systems, one should at least consider a cardiac source. Common causes of waveform abnormalities include congestive heart failure (elevated right heart pressures), arrhythmias, aortic stenosis and aortic insufficiency, and a number of nonpathologic etiologies. Although the Doppler waveform will appear abnormal in these cases, it should still be possible to acquire the quantitative velocity information necessary to reach a diagnosis regarding the presence and severity of any peripheral vascular disease as well.
Anomalous Vascular Blood Flow in the Presence of Right-Sided Aortic Arch
Authors: Miranda Carol
Published: March 2018

The congenital anomaly of right-sided aortic arch is often associated with aberration or isolation of the aorta's branch vessels. We report a case in which a carotid duplex examination revealed alterations in vascular flow patterns which led to the diagnosis of a right-sided aortic arch.
Profound Calf Muscle Dysfunction following Hip Dislocation Monitored by Air Plethysmography
Authors: Baker Nichole K. , Clay Amber L. , Brown Sandra L. , Eliason Jonathan L. , Wakefield Thomas W.
Published: March 2018

Introduction

Calf muscle atrophy is commonly noted after lower-extremity immobilization. Air plethysmography (APG) provides an easily reproducible, noninvasive diagnostic test that is useful in measuring calf ejection fraction. Quantitative measurements can be preformed before and after physical therapy as a tool to evaluate effectiveness of treatment.

Method

We report the case of a 26-year-old woman who presented to the vascular surgery clinic with right lower extremity cyanosis, paresthesias, and swelling after hip dislocation. The patient had been immobile for a month. An arteriogram was performed to rule out arterial injury and a lower-extremity ultrasound was performed to rule out deep venous thrombosis and venous reflux. APG revealed a profoundly abnormal ejection fraction of 36%. Physical therapy was recommended, with special attention towards calf muscle strengthening.

Results

After 3 months of physical therapy, the APG ejection fraction increased to a normal value of 74%. In addition to normalization of the APG, all symptoms of cyanosis, paresthesias, and swelling were resolved.

Conclusion

APG may be a useful tool in measuring the restoration of calf muscle function in patients with injuries requiring extended immobilization.
The Vascular Laboratory: A Proven Necessity for Optimal Vascular Disease Management but Rare in Developing Countries
Authors: Alwahbi Abdullah
Published: March 2018

It is well known that the noninvasive vascular laboratory is an important tool in the diagnosis and proper management of peripheral arterial disease; however, very few vascular centers in developing countries have this facility. This is mostly attributable to administrative obstacles, lack of interest from vascular surgeons, or insufficient resources. In this report, we present a brief overview of the importance of the vascular laboratory, our experience in the journey of establishing it, and try to give ideas to overcome obstacles.
Aortobifemoral Bypass Graft Distal Limb Large Anastomotic Pseudoaneurysm: A Case Report
Authors: Roberts Jason , Ali Vaqar , Pirris John
Published: March 2018

Early and late complications of aortic bypass grafting are well known and account for roughly 8% of all aortic bypass graft complication. Duplex ultrasound is the most widely used noninvasive modality in the early and latent detection and treatment of these complications with a reported >90% sensitivity rate. It can also be noted that duplex ultrasound as in this case study is not only sensitive enough to detect hemodynamic shifts but bypass graft anastamotic migrations as well.
Three-Dimensional Reconstruction of the Vessel Lumen as an Adjunct to the Cerebrovascular Duplex Evaluation
Authors: Porreca Francis J. , Rodriguez-Wong Angela , Hughes Joseph P.
Published: March 2018

Introduction

Color-flow duplex ultrasound is effective in the detection and quantification of carotid artery disease; however, diameter reduction estimates are most commonly derived by Doppler velocity measurements. In addition, direct visualization of the vessel lumen is only possible through the use of more expensive potentially invasive imaging procedures, such as computed tomography angiography, magnetic resonance angiography, and conventional angiography. Described here is a method to determine vessel diameter of the internal carotid artery (ICA) by the use of three-dimensional (3D) reconstruction of b-mode data to generate luminal diameter estimates.

Materials and Methods

A prospective review of 40 consecutive cerebrovascular duplex studies was performed. Testing protocols required transverse sweeps of the common carotid artery (CCA) and ICA in b-mode. Motion files were analyzed using software, which segmented the vessel lumen as the area of interest. The software created a 3D rendering of the lumen of the CCA and ICA. Vessel diameter reduction estimated by Doppler-derived velocities was then compared with the 3D rendering of the vessel lumen diameters.

Results

There was a 99% (n = 79, ρ = < 0.001) correlation between velocity estimates and 3D visualization for estimating diameter reduction. Correlation for cases with less than 50% diameter reduction by duplex was 100% (n = 66, ρ = < 0.004), whereas correlation for cases with 50% or greater diameter reduction by duplex was 92% (n = 13, ρ = < 0.03).

Conclusion

3D reconstruction of the vessel lumen shows a statistically significant correlation with velocity-derived diameter reduction measurements. Although more investigation with a larger group of patients is necessary, 3D reconstruction may be a valuable adjunct and may enhance the diagnostic capabilities of color-flow duplex ultrasound.
Uterine Artery Pseudoaneurysm in a Patient with Persistent Vaginal Bleeding
Authors: Olowoyeye Omodele Abosede
Published: March 2018

Uterine vascular abnormalities such as pseudoaneurysms, arteriovenous malformation, and true aneurysms are uncommon but potentially life-threatening lesions. A high index of suspicion is therefore necessary in making the diagnosis, especially in women of child-bearing age who present with unexplained vaginal bleeding. Predisposing factors to developing these conditions include a history of infection, curettage, therapeutic abortion, pelvic surgery, gestational trophoblastic disease, and endometrial carcinoma. The case report highlights the importance of color Doppler imaging in the detection and characterization of uterine vascular abnormalities.
Takayasu's Arteritis
Authors: Freedberg Robin , Savji Nazir , Benenstein Ricardo , Danilov Tatyana , Srichai Monvadi B. , Armas de Pedro , Saric Muhamed
Published: March 2018

Takayasu's arteritis is a chronic vasculitis of unknown etiology that typically occurs in women. It affects the aorta and its main branches, leading to either arterial stenoses or aneurysms. Here we report a case of a 42-year-old woman presenting with loss of peripheral vision in her left eye. On ultrasound imaging, she had distinctive findings of Takayasu's arteritis with marked circumferential thickening of the intimal-medial layer in the left common carotid artery and characteristic sparing of the carotid bulb and internal carotid artery. The diagnosis was further supported by computed topography findings of aneurysms in the subclavian artery and aorta. Awareness of these ultrasound findings may be of particular importance to many echocardiographers who are extending their practice into vascular imaging.
Contrast-Enhanced Ultrasound versus Computed Tomography Angiography in the Follow-Up of the Treatment of Abdominal Aortic Aneurysm with Endovascular Techniques
Authors: Tsolaki E. , Zenunaj Gladiol , Gresta Edo , Di Mase Stefano , Mascoli Francesco
Published: March 2018

In recent years, the advent of endovascular techniques has made possible the treatment of high-risk surgical patients. Nevertheless, the risk of short- and long-term complications is not insignificant. A surveillance program is therefore required to identify any possible complications and to monitor the efficacy of the treatment over time. In the various studies concerning follow-up after endovascular treatment for aortic aneurysm, computed tomography angiography is considered the “gold-standard.” Duplex ultrasonography provides accurate information regarding the patency of the stent graft and the evolution of the aneurysm sac size but is characterized by low sensitivity and specificity in the identification of endoleaks, which ranges from 70% to 90%. The use of contrast agents seems to increase the sensitivity in the identification of endoleaks. We evaluated the efficacy of contrast agents in the follow-up of patients after endovascular treatment and to compare results obtained from computed tomography angiography.
Intraluminal Soft-Tissue Mass versus Pedunculated Thrombus of Internal Jugular Vein in a Neonate
Authors: Methvien Janet , Moore Colleen , Brann Elizabeth
Published: March 2018

Introduction

—A 2 month old baby boy presented to the vascular lab for evaluation of left sided neck swelling. This case study details the use of duplex ultrasound in the evaluation and diagnosis of left internal jugular vein thrombus a rare condition in infants.

Case Report

—The patient had a CT scan which showed marked distention of the left jugular vein, as well as an intraluminal mass measuring approximately 2.3 × 1.8 × 2.7 cm. The study was interpreted as an intraluminal mass. Subsequent upper extremity duplex imaging was ordered for correlation. By duplex exam the patient was noted to have a 2–3 cm partially obstructing filling defect within the left jugular vein consistent with a pudunculated thrombus not excluding other etiologies. The patient was referred to a larger institution for further imaging. This confirmed the diagnosis of a pudunculated thrombus in the internal jugular vein.

Conclusion

—The incidence of internal jugular vein thrombus is unknown due to the limited number of studies available in this area.
Large Popliteal Vein Aneurysm: A Case Study
Authors: Roberts Jason , Ali Vaqar , Ashchi Majdi
Published: March 2018

Popliteal venous aneurysms are a rare vascular pathology, with only 125 surgical cases reported worldwide. This paper focuses on duplex ultrasound and the vascular technologists role in detecting rare lower-extremity vascular pathologies as they are presented.
Allergy and Other Risks of Ultrasound Gel: Recognition and Alternative Coupling Agents
Authors: Mueller Richard L. , Theoharis Evangelos
Published: March 2018

We recently encountered a patient who required urgent leg venous ultrasound. The patient warned us of a previous severe allergic reaction to ultrasound gel, an uncommon problem without a defined prevalence (according to our searches for literature on PubMed, Google Scholar, and uptodate.com ). The reaction was so severe that he permitted ultrasound only if an alternative agent could be used. We recalled both that allergy to gel is possible and that mineral oil could be used as a coupling agent in such cases and purchased a bottle on the spot while the patient waited. The clinical flexibility of switching to an alternative coupling agent turned out to be potentially life-saving because the patient was found to have an extensive deep venous thrombosis of the common femoral, femoral, deep femoral, popliteal, and gastrocnemius veins. This case report details this patient's course; reviews the potential adverse effects of ultrasound gel, proven and theoretical; demonstrates the excellent imaging characteristics of a large number of alternative coupling agents that we tested on our patient as well as another subject; and describes strategies for prevention and management of adverse effects. Although isolated case reports were found by literature search regarding use of alternative ultrasound coupling agents, we have found no review article or study evaluating as many agents as we have.
Description of a Phenomenon Resembling Spontaneous Echocardiographic Contrast in the Venous System
Authors: Cartman Gerry , Trachemontagne Helene , Yelle Marie-Claire , Abraham Cherrie Z.
Published: March 2018

Introduction.

—According to Beppu et al., spontaneous echocardiographic contrast (SEC or smoke) is a pattern of “spontaneous swirling echoes originally visualized by transthoracic echocardiography in the enlarged left atrium of patients with mitral stenosis” (J Am Cardiol 1985;6:744–749). It has since been primarily associated with atrial fibrillation and flutter. The clinical significance of SEC is its association with left atrial thrombus, increased thromboembolic complications, and death. The pathogenesis of SEC seems to involve Rouleau formation between red cells and fibrinogen at low shear rates, which is an in vitro equivalent of blood stasis. Black noted that “Red cell aggregation, manifested as SEC, appears to be a precursor to thrombosis. Left atrial thrombi are rich in fibrin and red cells, resembling venous more than arterial thrombi” (Echocardiography 2000;17(4):373–382).

Methods.

—If left atrial thrombi are associated with SEC and resemble venous thrombi, it was hypothesized that actual venous thrombi in previously undescribed locations, most notably deep vein thrombosis, may equally be associated with SEC. We asked our coauthors (H.T. and M-C.Y.) to search for such a phenomenon among patients referred to the vascular laboratory for suspected venous thrombosis.

Case Presentation.

—In the following case series, we report an original phenomenon of swirling echogenicity in the venous system that we believe is SEC. The phenomenon was fairly rare (maximum 1.5% of referred patients, whereas deep venous thrombosis itself was 15-20%). The clinical significance of this phenomenon is discussed.
Identifying Iliac Vein Stenosis with Duplex Ultrasonography
Authors: Ayoub Kathryn , Churgovich Carolyn , Mahlay Natalia Fendrikova
Published: March 2018

Introduction.

—Deep vein thrombosis should be considered as one of the differential causes of unilateral lower-extremity swelling. When the lower-extremity venous duplex ultrasound is negative for a deep vein thrombosis and a proximal occlusion is suspected, investigation should be completed with interrogation of the pelvic veins.

Case Report.

—We describe a 66-year-old man with a history of rectal carcinoma treated with chemotherapy, radiation, and proctosigmoidectomy who presented to the vascular laboratory with left lower-extremity swelling and erythema. A lower-extremity venous duplex was performed with a Phillips iU22 9–3 MHZ linear transducer, which revealed monophasic flow in the distal left external iliac vein with normal compression images. Further evaluation with a 5–1 MHZ curved array probe revealed a velocity shift within the external iliac vein consistent with iliac vein stenosis. A venogram confirmed a critical stenosis in the mid left external iliac vein with associated thrombus. The patient underwent mechanical thrombectomy and placement of 10 by 40 mm Smart stent. Post-interventional venogram demonstrated excellent antegrade flow and no evidence of residual thrombus.

Discussion.

—If left untreated, venous stenosis may predispose the patient to persistent lower extremity swelling, venous thrombosis, and venous stasis ulcers. Because of the underlying anatomic defect, symptoms may not improve with conservative management, including anticoagulation. Several diagnostic modalities can be considered for diagnosis of the venous stenosis, including venous duplex ultrasound, magnetic resonance venography, computed tomography with venous phase, venography, and intravascular ultrasound.

Conclusion.

—Cost considerations makes venous duplex a valuable, noninvasive, first-line method to investigate suspected venous stenosis.