bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is a Constant Doppler Angle of Insonation Worthwhile during Carotid Duplex Ultrasound?
Authors: Asbeutah Akram M. , Asbeutah Abdul Aziz A. , Swamy Nayanatara 
Published: March 2018

Background/Aims. —Velocity ratio is a good indication to determine the degree of vessel stenosis. This study was done to determine the effect of Doppler angle in carotid artery velocity ratio measurements. Methods. —Thirty-eight patients who underwent routine carotid duplex ultrasound were asked to participate in this study. Peak systolic velocity (PSV) and end-diastolic velocity (EDV) at distal common carotid artery (CCA) and proximal internal carotid artery (ICA) with constant and different Doppler angles were recorded. The ICA/CCA PSV ratio was calculated. Results. —There were 12 female and 26 male patients; their mean age (year, ±SD) was 50.53 ± 16.4 and their mean body mass index (kg/m2, ±SD) was 29.6 ± 9.53. The mean ± SD. ICA PSV, CCA PSV, and the ICA/CCA PSV ratio with a 60° Doppler angle were 80.40 ± 16.6, 87.90 ± 16.96, and 0.93 ± 0.18, respectively. However, the mean ± SD. ICA PSV, CCA PSV, and the ICA/CCA PSV ratio with a 45° Doppler angle were 63.84 ± 16.18, 70.67 ± 16.19, and 0.91 ± 0.17, respectively. Moreover, the ICA60°/CCA45° PSV ratio was 1.17 ± 0.25 and the ICA45°/CCA60° PSV ratio was 0.73 ± 0.16. Paired Student's t-test showed a statistical significance for different Doppler angle of insonation ( p = 0.001) but was not statistically significant when the Doppler angle was constant ( p = 0.389). Conclusion. —Constant Doppler angle is preferred during carotid ultrasound for a consistent result.
Impact of a Structured Duplex Ultrasound Hemodialysis Access Surveillance Program on Access Intervention Rates
Authors: Kundu Sanjoy , Modabber Milad , Chiu Brandon , You John M. , Moazzami Mitra , Babcock Rob 
Published: March 2018

Purpose —To assess the impact of a structured duplex ultrasound hemodialysis access surveillance program on the frequency of diagnostic fistulograms and endovascular interventions. Methods —A structured ultrasound hemodialysis access surveillance program was implemented at our institution on March 1, 2010. The access ultrasound comprised the measurement of vessel diameter, velocity, and flow in the feeding artery, anastomosis, and at specific points along the outflow vein (2.5, 5.0, 7.5, and 10 cm beyond anastomosis) along with a waveform pattern in the ipsilateral axillary and internal jugular vein. In this retrospective multicenter study, we compared the frequency of diagnostic contrast fistulograms and endovascular interventions (angioplasty) performed from March 2010 to February 2011 (12 months) by using the implemented ultrasound access surveillance program (postsurveillance) to the preceding 12 month period (March 2009 to February 2010) where no ultrasound access surveillance program was used (pre-surveillance). Results —Within our hemodialysis program, there was an average of 119 active fistulae during the presurveillance period versus 141 in the postsurveillance period. There were no significant demographic differences in our study populations across the two time frames ( p > 0.05). In the presurveillance period, 59 diagnostic contrast fistulograms were performed, whereas 47 diagnostic contrast fistulograms were performed during the post surveillance period. Using a two-sample test for equality of proportions, we found there was a significant decrease in the proportion of diagnostic contrast fistulograms after implementation of an access ultrasound surveillance program ( p = 0.0114). Similarly, 81 endovascular interventions were performed during the presurveillance period, whereas a significantly decreased number of endovascular interventions (n = 50) were performed postsurveillance ( p < 0.0001). Conclusions —There was a significant decrease in the number of invasive diagnostic contrast fistulograms and endovascular interventions upon implementation of an ultrasound access surveillance program. Such a structured surveillance program has the potential to provide significant reduction in patient discomfort and to minimize unnecessary invasive endovascular procedures.
Freehand 3D Ultrasound to Measure Thrombus Volume in Patients with Acute Deep-Vein Thrombosis
Authors: Zhao Limin , Kampmann Meghan , Prior Steven J. , Sorkin Michael J. , Braganza Melita , McEvoy Sue , Lal Brajesh K. 
Published: March 2018

Objective —Current imaging techniques are limited in their ability to quantify thrombus burden, progression, or resolution in patients with acute deep-vein thrombosis (DVT). These assessments are critical measures of therapeutic success when thrombolytic or thrombectomy treatment protocols are used for DVT. We have developed a novel freehand three-dimensional (3D) ultrasound method to measure thrombus volume. In this study, we evaluated the reliability of this new technology. Methods —We studied consecutive hospital inpatients with a first episode of acute DVT. Treatment decisions were not influenced by the study protocol. A combination of routine imaging in grayscale, color-flow, and power-Doppler modes along-with freehand 3D volumetric imaging with a linear transducer attached to an external tracking sensor was performed using a personal computer–based ultrasound scanner. Image-processing software loaded on the personal computer was used to process and reconstruct the serial cross-sectional images of the affected veins and outlined thrombus into a composite 3D image. Imaging and processing was performed twice by one sonographer, and repeated once by another sonographer. Results —The mean age of patients was 56.7 ± 15 years; 40% were women. A total of 70% of DVTs were in the lower extremity and 60% received anticoagulation. Thrombus volume was reliably determined by our protocol. The mean inter- and intraobserver differences in measurements were −0.09 ± 0.59 cm3 and 0.23 ± 0.43 cm3 (mean ± SD), which were well within 2 SD (Bland Altman statistics) of the mean volumes. Measurements of the second sonographer correlated well with those of the first (regression slope = 0.95 ± 0.07, p = 0.001) and those of the first observation correlated with the second observation performed by the same sonographer (regression slope = 0.91 ± 0.03, p = 0.001). Interrater agreement was good between the two sonographers (kappa = 0.71) and between two measurements by the same sonographer (kappa = 0.82). Conclusions —We have developed a novel freehand 3D-ultrasound imaging technique and protocol that reliably measures venous thrombus volume. There is good agreement in measurements between two observers and repeated measurements by one observer. The technique can be readily adapted for routine clinical practice. This protocol will be of increasing value as the appreciation for the deleterious effects of residual thrombus after DVT increases; and the use of aggressive thrombus removal treatments for acute DVT increases.
Comparison of in Vivo Arteriovenous Fistula Volume Flow Measurements Using a Transonic Transit-Time Ultrasound Flow Device and Doppler Ultrasound
Authors: Schroedter William B. , Burke Steven K. , Blair Andrew , Mendenhall Vince 
Published: March 2018

Introduction Doppler ultrasound (US) is extensively validated for classification of vascular disease based on velocity calculations. Although widely used to evaluate dialysis access arteriovenous fistulas (AVF), accurate volume flow measurements have proved more elusive, with significant variability resulting in large thresholds for differentiation of normally functioning from failing fistulae. We sought to compare in vivo measurements of AVF blood flow volume measured by the Transonic transit-time ultrasound flow device with those of Doppler US. Methods Bilateral femoral AVFs (n = 6) were created in swine (n = 3). Comparative volume flow measurements were made at baseline, 15, 30, 60, and 120 minutes after the creation of AVFs with the Transonic device and with Doppler US using an estimated time averaged velocity and the diameter of the vessel to calculate volume flow using the formula: Q = v A = v (π r2), where Q = volume flow, v = time and spatial averaged mean velocity, A = cross-sectional area, and r = radius of the vessel. Repeat measurements (minimum 3) were performed at each time point. Linear and multiple linear regression analyses were performed. Results Linear regression analyses showed a weak correlation (R2 = 0.103, p = 0.002) between Transonic and Doppler volume flow measurements. Doppler consistently showed greater volume flow over all time points than Transonic data. Average Transonic values had less variability over time (R2 = 0.9505) compared with average Doppler measurements (R2 = 0.7601). Average flow increased over time, regardless of the flow measurement device, consistent with reported clinical observation of AVF maturation process. Multiple linear regression analysis demonstrated correlation between Doppler and Transonic data (R2 = 0.197, p = 0.013), and provided a formula to estimate Transonic flow measurement from the Doppler data. [Transonic = 113.742 + (0.334 * Doppler)]. Conclusions Transonic data demonstrated a stronger relationship between volume flow and time than Doppler data, suggesting transit time ultrasound volume flow measurements may be more accurate. Doppler data tended to overestimate volume flow measurements; however, it may be feasible to use a correction factor for Doppler data that predicts Transonic results.
Longitudinal Changes in Size and Composition of Carotid Artery Plaques Using Ultrasound: Adaptation and Validation of Methods (Inter- and Intraobserver Variability)
Authors: Bjornsdottir Gudlaug , Sigurdsson Sigurdur , Sturlaugsdottir Ran , Gudmundsdottir Agnes , Eiriksdottir Gudny , Thorsson Bolli , Aspelund Thor , Gustavsson Tomas , Launer Lenore J. , Harris Tamara B. , Gudnason Vilmundur 
Published: March 2018

Introduction B-mode ultrasonography of the carotid arteries enables quantitative measurements of atherosclerotic plaque area and composition assessed as grayscale median (GSM). The purpose of this study was to set up a standardized ultrasound protocol to measure longitudinal changes in plaque area and composition and to determine the intra- and interobserver variability of the measurements in a longitudinal population based study, the Age Gene/Environment Susceptibility Reykjavik study. Method A total of 219 participants from the Age Gene/Environment Susceptibility Reykjavik study (76 ± 6 years old, 36% males) underwent 2-dimensional, B-mode ultrasound examination of the carotid arteries approximately 5 years apart for a longitudinal assessment of plaque area and composition. Standardized protocol was used to acquire comparable images from both visits. Ultrasound was performed bilaterally on the common carotid artery, internal carotid artery, and bifurcation. An image analysis program was modified and adapted for a longitudinal assessment of plaque area and plaque composition by GSM. Twenty-five subjects were selected from the group of 219 for intra- and interobserver variability assessment. Results Intraobserver variability for plaque area ranged from 12.10 to 18.63% and 0.89 to 0.96 for coefficient of variation and correlation (r), respectively, for plaque GSM ranged from 7.77 to 8.04% and 0.86 to 0.90. Interobserver variability for plaque area was 23.29% and 0.81 and 8.55% and 0.87 for plaque GSM. Conclusion The results from this study show that ultrasound can be used consistently for assessment of changes in plaque area and GSM over time. This can be achieved by proper training of ultrasound sonographers and by applying and following strict image acquisition and image analysis protocols.
Clinical and Ultrasound Sequelae of Nonvisualized Calf Veins on Duplex Ultrasound for Suspected Deep Vein Thrombosis
Authors: Henry Jon C. , Strosberg David , Warhadpande Shantanu , Satiani Bhagwan , Go Michael R. 
Published: March 2018

Objectives Calf veins are not visualized in up to 40% of lower extremity venous duplex ultrasounds (DUS). Little is known about the clinical implications of nonvisualized calf veins. We sought to investigate the incidence of nonvisualized calf veins, rate of subsequent venous thromboembolism (VTE), and factors influencing successful visualization on subsequent DUS. Methods We reviewed all patients who had DUS in 2012 at our institution who had nonvisualized calf veins, no deep vein thrombosis (DVT), and available follow-up. Demographics, Well's score, body mass index (BMI), indication for DUS, activity level, reason for nonvisualization, initial and subsequent DUS results, and subsequent occurrence of VTE were collected. Results A total of 8,237 DUS were performed in 2012. Of these, 891 (10.8%) DUS in 717 patients had at least one nonvisualized calf vein. Seven hundred twenty-eight limbs (484 patients) had no DVT and had available follow-up and comprised the study population. The most common reasons for nonvisualization were edema (35.5%) and body habitus (31.8%). Twenty-two (4.5%) patients were subsequently identified to have VTE; 9 limbs had only pulmonary emboli, 12 had only DVT, and 1 had both. Only length of stay in the hospital correlated with the development of VTE. One hundred forty-eight of the 484 patients had subsequent DUS at a median of 2.43 months; 45.3% of subsequent DUS successfully imaged the previously nonvisualized veins. Whole lower extremity swelling, single vein nonvisualization, and single limb nonvisualization at initial DUS were associated with successful visualization on subsequent DUS. Thirteen (8.8%) new DVT were seen on subsequent DUS, six were seen in calf veins that previously were not visualized, and seven were seen in either femoropopliteal veins or calf veins that previously were visualized and did not have thrombus. Conclusions Non-visualized calf veins are common in DUS. Almost half of patients with nonvisualized veins on initial DUS had successful visualization on subsequent DUS. Whole lower extremity swelling, single vein nonvisualization, and single limb nonvisualization at initial DUS were associated with successful visualization on subsequent DUS. In all, 4.1% of patients with nonvisualized veins on initial DUS go on to develop VTE and 8.8% of patients who have subsequent DUS are found to have DVT. When initial DUS is unable to visualize calf veins, selective repeat DUS may be useful to identify either new or initially unseen DVT.
Technology Dependence of Intima-Media Thickness Ultrasonographic Measurements
Authors: Braga Filipe Amorim , Salles-Cunha Sergio Xavier , de Barros Svetlana Maria Wanderlei , Pitta Guilherme Benjamim Brandão 
Published: March 2018

Introduction Ultrasonographic (US) measurements of intima-media thickness (IMT), particularly of the carotid arteries, have been used as a cardiovascular risk assessment tool. Variations in manual and semiautomatic measurements were investigated in an animal model—the aorta of 10 rabbits with dyslipedemia. Methods IMT was measured in B-mode images with 256 shades of gray using a 10 MHz probe by two independent investigators: (a) three same-place manual measurements were averaged in five distinct locations of the aorta of each rabbit for a total of 50 measurements per investigator (subgroups M1 and M2); (b) experimental software allowed for alterations in blood-intima and media-adventitia brightness line definition for IMT detection; observer 1 used brightness 50–200, adaptable to all images (SA1); observer 2 started with 10–60—the usual for human carotid measurements in this package—and increased values until IMT lines were visually acceptable; IMT was measured at optimized values for each image (SA2). Mean values were compared by using the paired t-test available in Excel. Results SA1 measurements, 0.379 ± 0.112 (SD) mm, were significantly smaller than SA2, 0.403 ± 0.122 mm, M1, 0.404 ± 0.149 mm, and M2, 0.405 ± 0.140 mm (<0.001 for all three SA1 versus SA2, M1 and M2 comparisons). Conclusion/Discussion Distinct automatic technologies, including (a) selection of blood-intima and media-adventitia brightness interfaces and (b) signal processing to “improve” line images, may alter IMT measurements significantly. Assumed population variations may be affected by technology used. IMT gender and age tables may be applicable only if the same measurement technology was used consistently.
Evaluating the effects of a physical activity on agitation and wandering (PAAW) experienced by individuals living with a dementia in care homes
Authors: Traynor Victoria , Veerhuis Nadine , Johnson Keryn , Hazelton Jessica , Gopalan Shiva 
Published: March 2018

Aim and Methods The aim was to evaluate the implementation of a structured physical activity (PA) programme for individuals living with a dementia in care homes. More specifically, the study aimed to test the effects on the behavioural and psychological symptoms of dementia (BPSD) using the Cohen-Mansfield Agitation Inventory and Algase Wandering Scale. The study was undertaken over 16 weeks using a quasi-experimental design. Registered nurses, physiotherapists, assistants in nursing and physiotherapy aids from one aged care organisation in NSW, Australia, undertook the study with academics. Results A total of 72 individuals living with a dementia from four care homes participated. Implementation of the structured PA programme generated statistically significant findings with reductions in agitation ( p < 0.001) and eloping ( p = 0.001) achieved for individuals living with a dementia in care homes. Conclusions Physiotherapists and exercise physiologists can complement nursing-focused care teams and contribute to a holistic model of care for individuals living with dementia in care homes. The study demonstrated how a structured PA programme positively affected the levels of agitation and wandering experienced by individuals living with a dementia. Individuals living with a dementia in care homes who participated in a structured PA experienced positive outcomes from the programme. The findings demonstrated that they benefited from the programme and PA should be promoted for this group just as it is for other population groups, including general populations of older people.
Subtherapeutic concentrations of infliximab and adalimumab are associated with increased disease activity in Crohn’s disease
Authors: Carlsen Arne , Omdal Roald , Leitao Kristian Øgreid , Isaksen Kjetil , Hetta Anne Kristine , Karlsen Lars Normann , Aabakken Lars , Bolstad Nils , Warren David , Lundin Knut E.A. , Grimstad Tore 
Published: March 2018

Background: Low anti-tumor necrosis factor α (TNFα) serum concentrations may result in lack of treatment response in patients with inflammatory bowel disease. We determined the anti-TNFα drug concentrations in patients with inflammatory bowel disease and investigated whether or not subtherapeutic drug concentrations were associated with increased levels of disease activity. Methods: In a single-center cross-sectional study, we included patients with ulcerative colitis or Crohn’s disease who were receiving infliximab or adalimumab maintenance therapy. Demographic data, disease activity symptom scores (Partial Mayo Score, Harvey Bradshaw Index), inflammatory markers [C-reactive protein (CRP), fecal calprotectin], antidrug antibodies and serum drug concentrations were recorded. Therapeutic drug concentrations were defined as 3–8 mg/liter for infliximab and 5–12 mg/liter for adalimumab. Results: Of 210 patients included, 137 (65.2%) had Crohn’s disease. In the adalimumab group, subtherapeutic drug concentrations were measured in 16.7% of patients with ulcerative colitis and in 27.7% of patients with Crohn’s disease. In the infliximab group, subtherapeutic drug concentrations were found in 23% (ulcerative colitis) and 30.3% (Crohn’s disease) of patients. In Crohn’s disease, subtherapeutic adalimumab concentrations were associated with higher fecal calprotectin and CRP concentrations compared with therapeutic concentrations. Subtherapeutic infliximab concentrations in patients with Crohn’s disease were also associated with higher CRP concentrations compared with therapeutic concentrations. Conclusions: The prevalence of subtherapeutic drug levels ranged from 17% to 30%. In patients with Crohn’s disease, subtherapeutic serum drug concentrations were associated with significantly higher disease activity with both anti-TNFα agents. These findings were not observed in patients with ulcerative colitis. Clinicaltrials.gov identifier [NCT02134054]
The relationship of depressive symptoms and functional and structural markers of subclinical atherosclerosis: A systematic review and meta-analysis
Authors: Wu Yupeng , Sun Dandan , Wang Bin , Li Yanfeng , Ma Yi 
Published: March 2018

Objectives The relationship of depressive symptoms and subclinical atherosclerosis remains controversial. We performed a systematic review and meta-analysis to evaluate the effect of depressive symptoms on the functional and structural markers of subclinical atherosclerosis as measured by carotid intima-media thickness (IMT), pulse wave velocity (PWV) and flow-mediated vasodilation (FMD). Methods A systematic literature search was performed electronically. Studies relating IMT, PWV or FMD to depressive symptoms were included. Standard/weighted mean differences (SMD/WMD) and corresponding 95% confidence intervals (95% CIs) were pooled in overall and subgroup analyses (age, sex, depression diagnosis, region, study design, site measured and sample size). Sensitivity analysis and publication bias were also conducted. Results Thirty-eight articles involving 5947 patients with depressive symptoms and 34,423 controls without depressive symptoms were included. Compared with controls without depressive symptoms, patients with depressive symptoms showed a significantly thicker IMT (SMD (95% CI) = 0.137 (0.047–0.227), p = 0.003), a higher PWV (SMD (95% CI) = 0.216 (0.139–0.293), p < 0.001) and a lower FMD (WMD (95% CI) = –2.554 (–3.709 to –1.399), p < 0.001). When analyzing subgroups with age and female ratio, all results were still significant ( p < 0.05) except IMT and FMD in age < 50 years subgroups ( p > 0.05). There was no statistical significance in sensitivity analysis and publication bias ( p > 0.05). Conclusions Depressive symptoms contributed toward subclinical atherosclerosis, and resulted in impaired functional and structural markers of subclinical atherosclerosis, which holds great promise in early prevention of cardiovascular disease.