bluuebunny/crossref_metadata_2025_split huggingface dataset:
Should Carotid Duplex Velocity Thresholds be Modified for Patients Undergoing Computed Tomographic Angiography?
Authors: Scissons Robert P. 
Published: March 2018

Purpose The use of computed tomographic angiography (CTA) has increased dramatically whereas angiography (ANGIO) has decreased proportionally. The purpose of this study is to evaluate the impact of this trend on internal carotid artery (ICA) ultrasound velocity criteria in the vascular laboratory. Methods Carotid duplex quality assurance (QA) databases were queried for similar cohorts of CTA and ANGIO ≥50% and ≥70% stenoses. Optimal velocity thresholds, sensitivity and specificity for ICA peak systolic velocity (PSV), end-diastolic velocity (EDV), peak systolic ICA, and common carotid artery ratio (carotid ratio) were obtained for CTA and ANGIO groups. Results A total of 101 vessels were analyzed in each group. Optimal PSV threshold, sensitivity, and specificity for CTA ≥50% stenosis was 152 cm/sec, 92.1% and 94.9% and for ANGIO, 170 cm/sec, 85.9% and 91.9%, respectively. When the optimal PSV threshold for the ANGIO group was applied to the CTA group, sensitivity and specificity were 85.7% and 94.7%, respectively. In the CTA group, PSV threshold was significantly lower when used to diagnose the ANGIO group ≥50% stenosis ( p = 0.0001). Optimal PSV, EDV, and PSV ratio thresholds for CTA ≥70% stenosis were 230 cm/sec, 62 cm/sec, and 2.7 and for ANGIO, 230 cm/sec, 68 cm/sec, and 3.2. Although no PSV differences were noted, when optimal EDV and PSV ratio thresholds for ANGIO ≥70%were applied to CTA ≥70%, EDV sensitivity and specificity were 80.9% and 94.7%, PSV ratio, 78.7% and 92.6%, respectively. CTA EDV and PSV ratio thresholds were statistically lower when used to diagnose ANGIO >70% stenosis ( p = 0.0001). Conclusions Optimal PSV threshold for ≥50% and EDV and PSV ratio thresholds for ≥70% ANGIO stenosis were lower, with significant differences in sensitivity and specificity found, when used to diagnose similar CTA stenoses. Modifying angiography-based carotid duplex velocity criteria may be warranted for patients who are evaluated with CTA.
A Systematic Literature Review of Ultrasonography for Morphology and Characterization of Vulnerable Carotid Artery Plaques
Authors: Kingstone Lysa Legault , Torres Carlos , Currie Geoff 
Published: March 2018

Background and Purpose Although ultrasound (US) evaluation of the carotid artery for stenosis is the accepted method for identifying risk factors for cerebrovascular (CV) events, patients with specific plaque morphology may be at increased risk. Plaque characterization via US is a potentially useful adjunct to stenotic grading for identifying vulnerable carotid disease. The aim of this study was to systematically review published clinical trials via the use of US to identify vulnerable plaques among both symptomatic and asymptomatic plaques. Methods We used a systematic search using Medline, Embase, and the Cochrane library databases to find relevant studies published between 2001 and 2011. We reviewed randomized, controlled human clinical trials that validated the applicability, diagnostic accuracy, and diagnostic impact of US carotid plaque characterization. For studies reporting qualitative findings, we abstracted information about the study design and technique and the quality of the methodology and analyzed the data using a modified Jadad scale. Results In this review, we identified 12 studies related to the evaluation of carotid plaque using US. The studies used a wide range of methodologies to quantify and image the plaque morphology. Published literature on this subject is lacking; however, this deficit may be because current studies are ongoing. Specific plaque characteristics identified as vulnerable included particular echo texture, the presence of echolucency and/or ulceration, surface alterations, and volume assessment using 3-dimensional US (3D US). In a minority of studies investigators used histopathology as the reference standard, and in most they used subsequent clinical observations. All studies demonstrated that US has good accuracy and specificity in identifying possible imaging characteristics related to vulnerable plaques. Conclusion The collected evidence shows that US is effectively able to detect specific carotid plaque characteristics related to high-risk plaques vulnerable for CV events. We anticipate that additional well-designed prospective studies will provide more definitive evidence and distinguish specific distinctive findings that may serve as indicators of vulnerable plaques. Our findings must be extended to demonstrate the accuracy and validity in everyday clinical imaging findings.
Diastolic Ankle-Brachial Indices as a Complementary Measure to Screen for Peripheral Arterial Disease in Diabetic Patients
Authors: Salles-Cunha Sergio X. , Braga Filipe A. , Caiafa Jackson S. , Melo Larissa H. A. , Castro Aldemar A. , Pitta Guilherme B.B. 
Published: March 2018

Introduction Ankle-brachial systolic pressure ratio or Index (ABI or ABI-S) has influenced cardiovascular screening for decades. Total or partial rigidity (i.e. calcification) of tibial arteries has hampered Doppler ABI-S measurements in patients with diabetes. Diastolic pressures are measurable with the oscillometric technique. The authors of a previous study demonstrated that ABI-D (ankle-brachial index based on diastolic pressure ratio) was less sensitive than ABI-S, but partial or total incompressibility of tibial arteries was suspected if ABI-D < ABI-S. This study examined whether ABI-D added information to screen for peripheral arterial disease (PAD) in patients with diabetes. Methods An “eye-to-foot” screening/educational program was performed at the city of Arapiraca, state of Alagoas, northeast of Brazil. A vascular surgeon, an expert on the diabetic foot, selected subjects with decreased pulse and/or older age. Bilateral arm and ankle pressures were performed in 71 diabetic patients: 47 (66%) women and 24 (34%) men, 68 ± 10 years (range, 46–86). ABI-S and ABI-D were calculated on the basis of bilateral brachial and ankle oscillometric pressures. Screening for PAD was compared on the basis of the prevalence of ABI < 0.90. Results ABI-S, ABI-D, or either ABI < 0.90 were detected in 36 (51%), 48 (68%), and 55 (77%) diabetics, respectively. ABI-S and ABI-D, only ABI-S, or only ABI-D were <0.90 in 53% (n = 29), 13% (n = 7), and 35% (n = 19) of the 55 diabetics with ABI < 0.90. The increase in frequency of ABI < 0.90 was significant if ABI-D complemented ABI-S ( p < 0.001 by chi-square). ABI-D and ABI-S were 0.83 ± 0.06 (0.68–0.895) versus 1.01 ± 0.10 (0.92–1.30) in the only ABI-D < 0.90 group. Conclusions Diastolic ankle pressures were estimated successfully by use of the oscillometric technique. Diastolic ABI correlated with expert physician assessment and contributed to quantitative screening for PAD in diabetic patients with apparently falsely elevated systolic ABI caused by partial incompressibility of tibial arteries.
Bilateral Deep Femoral Vein Thrombosis
Authors: Ratanaprasatporn Linda , Gonsalves Gail , Garcia-Toca Manuel , Slaiby Jeffrey M. , Marcaccio Edward J. , Chong Tec 
Published: March 2018

Introduction Deep vein thrombosis (DVT) is a major national health problem, especially among the critically ill and elderly. Most clinically significant DVTs involve the proximal veins of the lower limb, particularly the iliac, common femoral, femoral, and popliteal veins. Case Study We report a 53-year-old man sent to our vascular laboratory for ultrasound examination of the lower extremities to investigate the cause of nonpitting edema in both lower extremities. The ultrasound examination revealed isolated bilateral thrombosis in the deep femoral veins. Conclusion This is the first reported case of bilateral isolated deep femoral vein thrombosis.
Comparison of Duplex Ultrasound and Computed Tomography Surveillance after Endovascular Aneurysm Repair in Determining Proximal Endograft Location
Authors: Almaroof Babatunde H. , Ahanchi Sadaf S. , Chen Brian L. , Day Jarrod D. , Nelms Courtney R. , Panneton Jean M. 
Published: March 2018

Introduction —Color Duplex ultrasound (CDU) is the primary modality for endovascular abdominal aneurysm repair (EVAR) surveillance in our institution. Computed tomography (CT) scan (also known as CT scan or as CTA meaning CT Angiography) is, however, the gold standard to evaluate for endograft migration. We compared duplex ultrasound with CT scan for determination of proximal endograft location. Methods —A retrospective review was performed with the AneuRx® endograft of EVAR patients who had paired CDU and CTA imaging studies within a 3-month interval from January 2009 to June 2010. Patient demographics and distance measurements from the superior mesenteric artery (SMA) to the proximal graft on both CDU and CTA images were obtained. CTA measurements were done by measuring the distance between the SMA and the endograft using digital calipers. CTA patients did not fast. Duplex measurements were obtained in fasted patients by measuring the distance between the SMA and the hyperechoic proximal graft in the sagittal plane on B-mode and color-flow images. Correlation statistics was performed. Results —Twenty-two patients with 26 paired CTA and CDU studies were identified with a mean age of 73.3 years. There were 13 males (59.1%) and 9 females (40.9%). Mean interval between studies was 39.6 days (range, 0–84 days). Mean duplex SMA-endograft measurements were 21.8 ± 6.3 mm and mean CTA measurements were 17.3 ± 7.8 mm. Spearman's correlation coefficient (ρ) between both measurements was 0.44 ( p = 0.012). A subset of patients who had studies within a 1-month interval was also analyzed, with 11 paired studies identified. Mean CTA and duplex measurements were 20.2 ± 9.7 mm and 22.1 ± 7.2 mm respectively (ρ = 0.58; p = 0.031). Conclusion —There is a moderate correlation between CDU and CTA measurements of proximal endograft position after EVAR. Our data suggest that duplex ultrasound is valuable in assessing proximal Aneurx® endograft position and may be so reliable and accurate that it may eventually surpass CTA methodology typically used for assessing endograft migration to become the gold standard.
Differences in Saphenous Vein Reflux Detection According to Patient Positioning
Authors: Houle Marresa , Neuhardt Diana L. , Straight Nicole T. , Salles-Cunha Sergio X. 
Published: March 2018

Objective —To demonstrate differences in saphenous reflux detection performed with the use of a simplified protocol with the patient in the supine or reverse Trendelenburg positions (nonstanding) compared with an extensive protocol with the patient standing. Methods —Reflux detection in the standing and nonstanding positions were compared for measurements at the great saphenous vein (GSV-thigh, GSV-calf), small saphenous vein (SSV), and common femoral vein/saphenofemoral junction (CFV/SFJ). Reflux longer than 1 sec was considered a positive finding. A total of 171 measurement comparisons were made in 40 extremities of 20 women, ages 54 ± 13 years (range 34–82), all evaluated for varicose veins. False-negative (FN) results were calculated for standing and nonstanding positions compared with positive results obtained in the other position. Results —FN results in the nonstanding position were 49% (16/33), 38% (12/32), 27% (12/45), and 26% (9/35) for GSV-calf, GSV-thigh, SSV, and CFV/SFJ, respectively. FN results for the standing position were 6% (1/18) and 7% (2/28) for GSV-calf and CFV/SFJ, respectively. Technologists perceptions were that coaptable veins in the nonstanding position and detection of low-velocity reflux in the standing position influenced the results. Conclusions —The data collected favored evaluation of saphenous vein reflux in women with varicose veins in the standing position.
A Cross-Sectional Analysis of Femoral Artery Intima-Media Thickness
Authors: Wang Grace J. , Layne Andrew J. , Mohler Emile R. , Davis Julia T. , Sonnad Seema S. , Fairman Ronald M. 
Published: March 2018

Introduction. —Arterial intima thickness (IMT) of the carotid artery has been established as a surrogate marker of atherosclerosis. The role of femoral IMT remains incompletely defined. This study was undertaken to define the potential relationship between patient demographics, comorbidities, and femoral IMT and to establish it as a potential marker for future peripheral arterial disease. Methods. —A total of 160 patients (89 male, 71 female) between the ages of 18 and 50 years were enrolled and demographic data were obtained by chart review. Images of the common femoral artery were obtained with B-mode ultrasonography gated to the R-wave of the electrocardiograph. Automated edge detection software (Carotid Analyzer for Research) was used to measure femoral IMT and vessel diameter, and these measurements were used to derive the IMT cross-sectional area (CSA). Triplicate measurements of each femoral artery were made and averaged. T-tests and multivariate analysis were performed and significance was indicated by a p < 0.05. Results. —The mean femoral IMT measurements for men and women were 0.514 ± 0.011 mm and 0.465 ± 0.005 mm, respectively. Univariate analysis found significant differences in IMT for sex, age, and presence of diabetes, hypercholesterolemia, and hypertension. Univariate analysis found significant differences in CSA for sex, age, race, body mass index (BMI), and presence of chronic renal insufficiency and hypercholesterolemia. When significant variables were included in a multivariate regression, age and sex ( p < 0.001) remained significant predictors of IMT and age, sex, and BMI ( p < 0.001) remained significant predictors of CSA. Conclusions. —In this subset of patients, multivariate analysis revealed a thicker IMT in males and in patients ≥35 years of age. Greater IMT CSA was associated with male sex, age ≥ 35 and BMI ≥ 30. These findings have ramifications for the future study of femoral IMT as it relates to atherosclerosis and vessel remodeling.
Patterns and Distribution of Deep Vein Thrombus in the Lower Extremity
Authors: Sapp Brian , Craddock Garnet , Sapp James 
Published: March 2018

Introduction Practices vary widely among sonography laboratories in the imaging and evaluation of calf thrombus, contributing to diagnostic and treatment uncertainty. Our goal was to isolate and determine patterns of deep vein thrombus to question the level of sonography required for best diagnosis. Materials and Methods We retrospectively evaluated all patients that had a positive venous duplex exam from 2004 to 2013. Our lab performed 11,503 venous studies during the 8-year period, with 382 showing, via symptom review and reporting, acute first-time thrombus. Results Mean age 62 years 8 months old, 209 females (54.71%), 171 male (44.76%), 221 left sided (57.85%), 161 right sided (42.15%). Percentages for the following segments: above the knee (139, 36.39%), calf (375, 98.17%), superficial (54, 14.14%), IVC (14, 3.66%), iliac (36, 9.42%), CFV (67, 17.54%), PFV (7, 1.83%), FV (114, 29.84%), popliteal AK (123, 32.20%), popliteal fossa (142, 37.17%), popliteal BK (148, 38.74%), gastrocnemius veins (141, 36.91%), peroneal (243, 63.61%), posterior tibial vein (191, 50.00%), soleal (109, 28.53%), anterior tibial veins (3, 0.79%), great saphenous vein (38, 10%), small saphenous vein (18, 5%), and varicosities (8, 2%). Conclusion Calf vein thrombus is found with above the knee thrombus (98.17%). Peroneal (63.61%), posterior tibial (50%), gastrocnemius (36.91%), and soleal (28.53%) veins should be routinely imaged. Binomial logistic regression was conducted with eleven-predictor variables significantly predicted proximal thrombus (above the knee). A test with all eleven-predictor variables, compared with the null model, was significant ( x2 [14] = 288.511, p < 0.001), showing that these variables predict above-the-knee thrombus better than without them (or by chance). We have developed a tool that shows the potential trajectories or tracks of a given patient's DVT (with associated probabilities), based on aggregated patient data.
Ultrasonographic Tissue Characterization of Kidneys in Patients with Unilateral Renal Artery Stenosis
Authors: Engelhorn Ana Luiza D. Valiente , Engelhorn Carlos A. , Salles-Cunha Sergio X. , Andruska Gabriele , Batisti Karolini 
Published: March 2018

Introduction Ultrasound tissue characterization (USTC) has been applied to B-mode images of normal, young and transplanted kidneys, carotid, and peripheral atherosclerosis and venous thrombosis. We analyzed USTC from both kidneys of patients with severe unilateral renal artery stenosis. Seven women and 11 men, 79 ± 9 standard deviation (range = 57–96) years of age, were included. Severe, unilateral, renal artery stenosis was based on renal artery peak-systolic velocity (PSV) > 200 cm/sec and/or renal-aortic PSV ratio > 3.5. This sample population, selected sequentially by date of ultrasonographic examinations requested, was heterogeneous: kidney lengths and resistivity indices varied from 6.7 to 13.4 cm and 0.45 to 0.85. Methods USTC was applied to images selected for kidney length measurements. Pixel brightness in the 0–255 range was rescaled to zero for black and 200 for fascia brightness. Gray-scale medians (GSM) of entire kidneys were estimated for statistical comparisons between: (a) kidneys ipsilateral to stenosis (KIS), (b) kidneys contralateral to stenosis (KCS), and (c) normal, young kidneys (KN), previously published GSM = 37 ± 6 (27–48). Results Two distinct KCS subgroups were identified: (1) near-normal GSM < 54 (KCSN, n = 10, 56%); and (2) elevated GSM > 60 (KCSH, n = 8, 44%). Subgroup increasing GSM order was (1) KN, (2) KCSN (47 ± 7, > KN, p < 0.002), (3) KIS-CN (59 ± 20, >KCSN, p < 0.003), (4) KIS-CH (73 ± 20, > KCSN, p < 0.007), and (5) KCSH (78 ± 17, >KIS-CN, p < 0.05). GSM was independent of kidney length or resistivity index, with Pearson correlation coefficients < 0.5 for either KIS or KCS, respectively. Conclusions Tissue echogenicity, represented by GSM, was an independent variable characterizing effects of unilateral renal artery stenosis on the ipsilateral or on both kidneys.
Duplex Ultrasound Detection of a Chronic Contained Rupture of an Abdominal Aortic Aneurysm
Authors: Warren Melissa N. , Roberts Jason 
Published: March 2018

Introduction Chronic containment of a ruptured abdominal aortic aneurysm (AAA) is a rare clinical phenomenon that is often accompanied by abstract symptomatology, delayed diagnosis, and treatment. We describe a case of chronic contained rupture (CCR) in a hemodynamically stable and asymptomatic patient detected by duplex ultrasound (DU). Patient Description A 71-year-old white male presented to our medical facility to establish cardiac care for newly diagnosed pleural effusion and bilateral lower extremity edema. Physical examination revealed prominent abdominal aortic pulsations. An abdominal DU was ordered to evaluate for an AAA. Methods An abdominal DU examination was performed utilizing a Philips iU22 xMATRIX Ultrasound System equipped with a C5–1 MHz PureWave transducer. The aorta, common iliac and external iliac arteries were evaluated with gray scale, color, and spectral Doppler applications. Imaging Results The DU confirmed the presence of a 5.6 cm × 5.7 cm infrarenal AAA. The lumen was noted to have irregularities and multiple avascular hypoechoic lesions that were reproducible in multiple imaging planes. Computed tomography (CT) confirmed the presence of the 4.8-cm aneurysm accompanied by a 5.6 cm × 4.0 cm multi-lobular fluid collection extending into the mesentery. Active extravasations were not visualized during contrast administration; nevertheless, the appearance of the irregularity was suspicious of aneurysm leak resulting in evolving hematoma. The CCR was treated with a bifurcated intraluminal stent graft. Conclusion This case describes an extremely rare rupture complication that may be present during routine evaluation of the abdominal aorta. Because of its rarity in case presentation, standardized protocol for detection and sonographic presentation remain undocumented.
Statin Therapy Does Not Significantly Alter Microvascular Function in Uncomplicated Hypertension
Authors: Bleakley Caroline , McCann Aaron , McClenaghan Vivienne , Hamilton Paul Kevin , Pumb Richard , Harbinson Mark , McVeigh Gary Eugene 
Published: March 2018

Objective Young patients with uncomplicated hypertension are frequently exempt from statin therapy as they generally fall below current treatment thresholds. This study examined whether there may be evidence of improved microvascular function in young patients with grade 1 hypertension after 12 weeks of statin therapy. Methods This was a randomized double-blind placebo-controlled crossover study in which 42 statin-naïve participants with grade 1 hypertension (mean systolic/diastolic blood pressure 142/92 mmHg) were randomized to receive either simvastatin 40 mg or a placebo for 12 weeks, followed by a 4-week washout period, after which the arms crossed for a further 12 weeks. Measures of vascular function were recorded at the beginning and end of each study period equating to four measures in total. The brachial artery was studied by flow-mediated dilatation (FMD) together with the resistive and pulsatility indices and mean velocity of flow. Results Statin therapy did not significantly alter the change in FMD seen in the brachial artery [standardized differential mean = 0.02 (0.23), confidence interval (CI) = −0.45 to 0.48, p = 0.932]. No significant changes were seen in the brachial artery mean velocity (CI = −9.68 to 11.51, p = 0.861), resistive index (CI = −0.11 to 0.12, p = 0.903), or pulsatility index (CI = −5.82 to 4.91, p = 0.864). Conclusion This study did not demonstrate any significant changes in established measures of microvascular function after treatment with a statin in a young hypertensive population with no antecedent cardiovascular disease. This may indicate that either the intervention was insufficiently vasoactive to produce a clinically detectable improvement in vascular function, or that the means used to assess the microvasculature were insufficiently sensitive to detect what may have been quite minor changes.