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Drees Randi R VMTH DSS, UW-Madison, Madison, WI, 53726, - - 2014
Companion animals are routinely anesthetized or heavily sedated for cardiac MRI studies, however effects of varying anesthetic protocols on cardiac function measurements are incompletely understood. The purpose of this prospective study was to compare effects of two anesthetic protocols (Protocol A: Midazolam, fentanyl; Protocol B: Dexmedetomidine) on quantitative and qualitative ...
Wetscherek Andreas A Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, - - 2014
The pseudo-diffusion coefficient D(*) in intravoxel incoherent motion (IVIM) imaging was found difficult to seize. Flow-compensated diffusion gradients were used to test the validity of the commonly assumed biexponential limit and to determine not only D(*) , but also characteristic timescale τ and velocity v of the incoherent motion. Bipolar ...
Allen Bradley D BD Department of Radiology, Northwestern University, 737 N. Michigan Ave., Suite 1600, Chicago, IL 60611, USA - - 2014
The left ventricular outflow tract (LVOT) peak pressure gradient is an important haemodynamic descriptor in patients with hypertrophic cardiomyopathy (HCM); however, secondary alterations in aortic blood flow have not been well described in these patients. Aortic flow derangement is not easily assessed by traditional imaging methods, but may provide unique ...
Hansen Kristoffer Lindskov KL Department of Radiology, Rigshospitalet, Copenhagen University Hospital, Denmark. Electronic address: - - 2014
The vector velocity method Transverse Oscillation (TO) implemented on a conventional ultrasound (US) scanner (ProFocus, BK Medical, Herlev, Denmark) can provide real-time, angle-independent estimates of the cardiac blood flow. During cardiac surgery, epicardial US examination using TO was performed on (A) 3 patients with healthy aortic valve and (B) 3 ...
Iwashima Satoru S Department of Pediatrics, Hamamatsu University School of - - 2014
Background:We evaluated the hemodynamic status of patent ductus arteriosus (PDA) by measuring vena contracta width (VCW) and effective shunt orifice area (ESOA) using proximal isovelocity surface area (PISA) on color Doppler imaging.Methods and Results:Study subjects were 21 patients with PDA (mean age, 3.6 years). We measured VCW (mm/m(2)) and ESOA (cm(2)) by ...
Fadnes Solveig S MI Lab and the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: - - 2014
High-frame-rate ultrasound speckle tracking was used for quantification of peak velocity in shunt flows resulting from septal defects in congenital heart disease. In a duplex acquisition scheme implemented on a research scanner, unfocused transmit beams and full parallel receive beamforming were used to achieve a frame rate of 107 frames/s ...
Jardin T T Institut Supérieur de l'Aéronautique et de l'Espace, University of Toulouse, 10 avenue Edouard-Belin, Toulouse, 31055, - - 2014
While a leading-edge vortex on an infinite translating wing is shed after a short distance of travel, its counterpart on a finite span revolving insect wing or maple seed membrane exhibits robust attachment. The latter explains the aerodynamic lift generated by such biological species. Here we analyze the mechanisms responsible ...
Xian-Shui Fu F Department of Ultrasound,Peking University Third Hospital,Beijing 100191,China;Department of Ultrasound,First Affiliated Hospital of General Hospital of PLA,Beijing - - 2014
Objective To evaluate the diagnostic values of gray-scale and color Doppler ultrasound in the diagnosis of focal Hashimoto's thyroiditis(FHT). Methods The gray-scale and colour Doppler ultrasound data of 120 patients with histopathologically confirmed FHT were retrospectively studied. The background of thyroid parenchyma was subjectively evaluated as absence or presence of ...
Yun B Min BM G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, - - 2014
Despite pressing needs, there are currently no FDA approved prosthetic valves available for use in the pediatric population. This study is performed for predictive assessment of blood damage in bileaflet mechanical heart valves (BMHVs) with pediatric sizing and flow conditions. A model of an adult-sized 23mm St. Jude Medical (SJM) ...
Iwamoto Yoichi Y Department of Diagnostic Imaging, Hospital for Sick Children and University of Toronto, 555 University Ave., Toronto, Ontario, M5G1X8, - - 2014
Phase-contrast magnetic resonance (MR) has been widely used for quantification of aortic regurgitation. However there is significant practice variability regarding where and how the blood flow data are acquired. To compare the accuracy of flow quantification of aortic regurgitation at three levels: the ascending aorta at the level of the ...
Sasaki Tomohiko - - 2014
Crohn's disease (CD) is routinely evaluated using clinical symptoms, laboratory variables, and the CD activity index (CDAI). However, clinical parameters are often nonspecific and do not precisely reflect the actual activity of CD small-intestinal lesions. The purposes of this prospective study were to compare color Doppler ultrasound (US) findings with ...
Perren Fabienne F Division of Neurology, Department of Clinical Neurosciences, HUG, University Hospital and Medical Faculty of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211, Geneva 14, Switzerland, - - 2014
Arterial tortuosity of the posterior circulation compressing the facial nerve induces the ephaptic axono-axonal cross-talk that sparks hemifacial spasm. We sought if a noninvasive method such as color duplex of these arteries might detect hemodynamical changes in this condition. Nine patients with hemifacial spasm, successfully treated with botulinum toxin, were ...
Morrison Derek D Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX - - 2014
A computational program, called the groundwater flow calculator, was created to quickly and easily determine the hydraulic gradient and direction of groundwater flow. The groundwater flow calculator automates the hand-drawn process by Ralph Heath in the U.S. Geological Survey (USGS) Water Supply Paper 2220. In addition, a mobile app was ...
Venugopal A A Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, - - 2014
In the present study, a novel dual sensor vortex cross correlation technique is suggested and implemented to extend the lower operating range of the flowmeter. The first sensor located at an optimum streamwise location of 0.85 times the width of the bluff body is employed to compute the vortex shedding ...
Jun Brian - - 2014
The hinge regions of the bileaflet mechanical heart valve (BMHV) can cause blood element damage due to the complex and unsteady nature of flow within these regions. Recently, a Micro Particle Image Velocimetry (µPIV) system was developed to study whole flow fields within BMHV hinge regions with enhanced spatial resolution ...
Moore Brandon B Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado - - 2014
The aortic sinus vortex is a classical flow structure of significant importance to aortic valve dynamics and the initiation and progression of calific aortic valve disease. We characterize the spatio-temporal characteristics of aortic sinus voxtex dynamics in relation to the viscosity of blood analog solution as well as heart rate. ...
Agostino Fletcher J - - 2014
Small-volume continuous-flow synthesis (small-volume CFS) offers a number of benefits for use in small-scale chemical production and exploratory chemistry. Typically, small-volume CFS is followed by discontinuous purification; however, a fully continuous synthesis-purification combination is more attractive. Milli free-flow electrophoresis (mFFE) is a promising continuous-flow purification technique that is well suited ...
Tien W-H WH Department of Aeronautics and Astronautics, University of Washington, Seattle, WA, - - 2014
The majority of bioprosthetic venous valves do not have a sinus pocket and, in practice, they are often placed in non-sinus segments of the veins. The aim of this study is to investigate the effect of the sinus pocket on the flow dynamics in a prosthetic valve. A bench top ...
Hoganson David M DM 2 Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO - - - 2014
Stenosis in a vascular access circuit is the predominant cause of access dysfunction. Hemodynamic significance of a stenosis identified by angiography in an access circuit is uncertain. This study utilizes computational fluid dynamics (CFD) to model flow through arteriovenous fistula to predict the functional significance of stenosis in vascular access ...
Sieskiewicz Andrzej A Department of Otolaryngology, Medical University of Bialystok, Poland. Electronic address: - - 2014
To assess blood flow velocity in the middle cerebral artery (MCA) during transnasal endoscopic procedures performed with decreased hemodynamic parameters. In 40 patients who underwent endoscopic skull base surgery in controlled hypotension (studied group) and in 13 patients operated without reduction of hemodynamic parameters (control group), blood flow velocity in ...
Hamidi Cihad C Department of Radiology, Medical School, Dicle University, Diyarbakir, - - 2014
To compare retrobulbar blood flow in patients with central serous chorioretinopathy (CSC) and healthy subjects using color Doppler ultrasonography. Thirty patients (age 23-54 years) with a first episode of acute CSC and 30 healthy controls (age 30-44 years) were evaluated. The peak systolic blood flow velocity, end-diastolic velocity (EDV), resistance ...
Dos Reis Gisele Fm GF 1Veterinary Medicine Department, Veterinary School, Garça, São Paulo, - - 2014
The qualitative and quantitative aspects of femoral artery blood flow waveform spectra were evaluated in 15 male and 15 female Persian and mixed breed domestic felines (Felis catus), which were healthy and not sedated, using duplex Doppler ultrasonography (DDU). Spectral Doppler demonstrated a biphasic characteristic in 16 (53.34%) of the ...
Vuong Barry - - 2014
We report a technique for blood flow detection using split spectrum Doppler optical coherence tomography (ssDOCT) that shows improved sensitivity over existing Doppler OCT methods. In ssDOCT, the Doppler signal is averaged over multiple sub-bands of the interferogram, increasing the SNR of the Doppler signal. We explore the parameterization of ...
Leitgeb Rainer A RA Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, - - 2014
Optical Coherence Tomography (OCT) has revolutionized ophthalmology. Since its introduction in the early 1990s it has continuously improved in terms of speed, resolution and sensitivity. The technique has also seen a variety of extensions aiming to assess functional aspects of the tissue in addition to morphology. One of these approaches ...
Vanderschueren Geraldine A K B GA Department of Neurology, Atrium Medical Centre, Heerlen, The - - 2014
Introduction Doppler sonography may detect increased intraneural blood flow of the median nerve in carpal tunnel syndrome (CTS). Objective Critically review the present literature about the diagnostic value of increased intraneural flow detected by sonography in CTS. Methods Systematic review of studies published between 1985 and 2013. Results The 7 ...
Talati Pratik P Neuroscience Program, Vanderbilt University, Nashville, TN, 37235; Department of Psychiatry, Vanderbilt University, Nashville, TN, - - 2014
The human hippocampal formation is characterized by anterior-posterior gradients of cell density, neurochemistry and hemodynamics. In addition, some functions are associated with specific subfields (subiculum, CA1-4, dentate gyrus) and regions (anterior and posterior). We performed contrast-enhanced, high-resolution T1-weighted 3T steady state (SS) imaging to investigate cerebral blood volume (CBV) gradients ...
Bohner Bíborka B Department of Physical Chemistry and Materials Science, University of Szeged, Szeged, H-6720, Hungary. - - 2014
We have analyzed the emerging precipitate pattern of calcium-oxalate in a flow system. The circular symmetry is broken because of the hydrodynamic instability at the tip of the underlying gravity current. The presence of a concentration gradient maintained by the flow leads to the enrichment of the thermodynamically unstable calcium ...
Hsiao Albert A Department of Radiology, Stanford University, Stanford, California, - - 2014
To determine whether it is feasible to use solely an accelerated 4D phase-contrast magnetic resonance imaging (4D-PC MRI) acquisition to quantify net and regurgitant flow volume through each of the cardiac valves. Accelerated, 4D-PC MRI examinations performed between March 2010 through June 2011 as part of routine MRI examinations for ...
Imamoglu E Y EY Zeynep Kamil Maternity and Children's Training and Research Hospital, Neonatal Intensive Care Unit Istanbul, Istanbul, - - 2014
Objective:The objective of this study is to investigate the effects of antenatal magnesium sulfate (MgSO4) on cerebral blood flow (CBF) velocities in preterm neonates.Study Design:In this prospective case-control study, we included 53 neonates born between 26 and 34 weeks of gestation. Twenty neonates were exposed to MgSO4 antenatally and 33 ...
Logallo Nicola N Department of Clinical Medicine, University of Bergen, Bergen, - - 2014
Ultrasound contrast agents (UCA) salvage a considerable number of transcranial Doppler (TCD) exams which would have failed because of poor bone window. UCA bolus injection causes an undesirable increase in measured blood flow velocity (BFV). The effect of UCA continuous infusion on measured BFV has not been investigated, and some ...
Kalaycı Belma B Clinic of Cardiology, Karaman State Hospital; Karaman-Turkey. - - 2014
The quantitative parameters which are used to assess the severity of aortic regurgitation (AR) provide the most accurate information whereas these parameters are difficult and time-consuming. The aim of this study was to get a practical parameter to use in daily practice for assessing the severity of aortic regurgitation. The ...
Xu Tiantian T Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, - - 2014
In previous studies, we proposed blood measurement using speckle size estimation, which estimates the lateral component of blood flow within a single image frame based on the observation that the speckle pattern corresponding to blood reflectors (typically red blood cells) stretches (i.e., is "smeared") if blood flow is in the ...
Peterson Lindsy M LM Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 - - 2014
Doppler OCT (DOCT) can provide blood flow velocity information which is valuable for investigation of microvascular structure and function. However, DOCT is only sensitive to motion parallel with the imaging beam, so that knowledge of flow direction is needed for absolute velocity determination. Here, absolute volumetric flow is calculated by ...
Binder Ronald K RK St. Paul's Hospital, University of British Columbia, Vancouver, - - 2014
Background: Transcatheter aortic valve replacement (TAVR) is less invasive than surgical aortic valve replacement and may be preferred for patients, who refuse blood transfusions. Objectives: Our study sought to define transfusion rates in TAVR, identify predictors and develop recommendations for patients, who refuse transfusions. Methods: A large cohort of consecutive ...
Vachutka Jaromir - - 2014
The objective of this study is to investigate the effect of multiple dead elements in an ultrasound probe on the accuracy of Doppler ultrasound measurements. For this work, we used a specially designed ultrasound imaging system, the Ultrasonix Sonix RP, that provides the user with the ability to disable selected ...
Wang Bo B UPMC Eye Center, Eye and Ear Institute, Ophthalmology and Visual Science Research Center, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America; Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America; Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of - - 2014
To investigate gold nanorods (GNRs) as a contrast agent to enhance Doppler optical coherence tomography (OCT) imaging of the intrascleral aqueous humor outflow. A serial dilution of GNRs was scanned with a spectral-domain OCT device (Bioptigen, Durham, NC) to visualize Doppler signal. Doppler measurements using GNRs were validated using a ...
Koyama Tomiyasu T Hokkaido University, 064-0821, Sapporo, Hokkaido N-1W-25, Japan, - - 2014
Forced retrograde perfusion through the venous system with arterial blood can provide adequate oxygen to peripheral tissues at rest through veno-capillary networks which is the basis for surgical restoration of blood flow by distal vein arterialization (DVA). To be successful such surgery requires disruption of valve leaflets in the veins, ...
van der Eijk A C AC Department of BioMechanical Engineering, Faculty of Mechanical, Maritime & Materials Engineering, Delft University of Technology, Delft, The Netherlands Department of Neonatology, Erasmus MC, Sophia Children's Hospital, University Medical Center Rotterdam, Rotterdam, The - - 2014
In multi-infusion IV therapy, the actual volume delivered to the neonate can vary over time. To reduce flow rate variability, check valves can be used. A check valve allows flow through the valve in only one direction. To evaluate flow rate variability in a low flow dual-infusion setup with and ...
Wu Jian-Xing JX Department of Biomedical Engineering, National Cheng Kung University, Tainan City 70101, - - 2014
This study proposes multiple-site hemodynamic analysis of Doppler ultrasound with an adaptive color relation classifier for arteriovenous access occlusion evaluation in routine examinations. The hemodynamic analysis is used to express the properties of blood flow through a vital access or a tube, using dimensionless numbers. An acoustic measurement is carried ...
Biechler Stefanie V SV Department of Cell Biology and Anatomy, School of Medicine, University of South Carolina Columbia, SC, - - 2014
One percent of infants are born with congenital heart disease (CHD), which commonly involves outflow tract (OFT) defects. These infants often require complex surgeries, which are associated with long term adverse remodeling effects, and receive replacement valves with limited strength, biocompatibility, and growth capability. To address these problematic issues, researchers ...
Shiodera Taichiro T Corporate Research and Development Center, Toshiba Corporation, 1, Komukai-Toshiba-cho, Saiwai-ku, Kawasaki, 212-0001, Japan, - - 2013
The Time-Spatial Labeling Inversion Pulse (Time-SLIP) technique enables tracing of regional fluid flows without the use of contrast medium. The objective of this study is to quantify automatically slow and complex fluid flows using the Time-SLIP technique. Series images were acquired with a 1.5-T MRI scanner using the Time-SLIP technique ...
Mahadevia Riti R Northwestern University, Chicago, - - 2013
Aortic 3D blood flow was analyzed to investigate altered ascending aorta (AAo) hemodynamics in bicuspid aortic valve (BAV) patients and its association with differences in cusp fusion patterns (right-left, RL versus right-noncoronary, RN) and expression of aortopathy. 4D flow MRI measured in vivo 3D blood flow in the aorta of ...
Middione Matthew J MJ Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California, USA; Biomedical Physics Interdepartmental Program, University of California, Los Angeles, Los Angeles, California, - - 2013
To evaluate convex gradient optimization (CVX) for increased spatiotemporal resolution and improved accuracy for phase-contrast MRI (PC-MRI). A conventional flow-compensated and flow-encoded (FCFE) PC-MRI sequence was compared with a CVX PC-MRI sequence using numerical simulations, flow phantom experiments, and in vivo experiments. Flow measurements within the ascending aorta, main pulmonary ...
Semaan Edouard - - 2013
To provide a more complete characterization of aortic blood flow in patients following valve-sparing aortic root replacement (VSARR) compared with presurgical cohorts matched by tricuspid and bicuspid valve morphology, age and presurgical aorta size. Four-dimensional (4D) flow magnetic resonance imaging (MRI) was performed to analyse three-dimensional (3D) blood flow in ...
Bazan Ovandir - - 2013
In vitro hydrodynamic characterization of prosthetic heart valves provides important information regarding their operation, especially if performed by noninvasive techniques of anemometry. Once velocity profiles for each valve are provided, it is possible to compare them in terms of hydrodynamic performance. In this first experimental study using laser doppler anemometry ...
Hockley F A - - 2014
Riverine fish are subjected to heterogeneous flow velocities and turbulence and may use this to their advantage by selecting regions that balance energy expenditure for station holding while maximizing energy gain through feeding opportunities. This study investigated microhabitat selection by guppies Poecilia reticulata in terms of flow characteristics generated by ...
Qu Xiaofu X Division of Periodontology and Endodontology, Department of Oral Biology, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan; Dalian Stomatological Hospital, Changjiang Road 935, Shahekou District, Dalian 116021, - - 2014
Human pulpal blood flow (PBF) signals as measured by laser Doppler flowmeter (LDF) decrease with age. Although this decrease is considered to be due in part to slow blood flow, information regarding this velocity in humans has been lacking. The aims of the present study were to estimate the blood ...
von Knobelsdorff-Brenkenhoff Florian - - 2013
Aortic remodeling after aortic valve replacement (AVR) might be influenced by the postoperative blood flow pattern in the ascending aorta. This pilot study used flow-sensitive four-dimensional magnetic resonance imaging (4D-flow) to describe ascending aortic flow characteristics after various types of AVR. 4D-flow was acquired in 38 AVR patients (n=9 mechanical, ...
Sumikura Horohito - - 2013
We have used in-body tissue architecture technology to develop an autologous valved conduit with intact sinuses of Valsalva (biovalve). In this study, we fabricated three different forms of biovalves and evaluated their function in vitro using a mock circulation model to determine the optimal biovalve form for aortic valve replacement. ...
Mehregan Forough - - 2013
We propose a new approach to quantification of intracardiac vorticity based on conventional color Doppler images -Doppler vortography. Doppler vortography relies on the centrosymmetric properties of the vortices. Such properties induce particular symmetries in the Doppler flow data that can be exploited to describe the vortices quantitatively. For this purpose, ...
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