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— An approach to estimate blood flow cross-sectional velocity profiles in intravital microscopy videos of post-capillary venules is proposed. Given an image sequence, the cross-section upon which the velocity profile is to be estimated is manually chosen. The velocity of each streamline, assumed perpendicular to the chosen cross-section, is estimated(More)
BACKGROUND We sought to investigate the use of a new parameter, the projected effective orifice area (EOAproj) at normal transvalvular flow rate (250 mL/s), to better differentiate between truly severe (TS) and pseudo-severe (PS) aortic stenosis (AS) during dobutamine stress echocardiography (DSE). Changes in various parameters of stenosis severity have(More)
BACKGROUND The effective orifice area (EOA) is the standard parameter for the clinical assessment of aortic stenosis severity. It has been reported that EOA measured by Doppler echocardiography does not necessarily provide an accurate estimate of the cross-sectional area of the flow jet at the vena contracta, especially at low flow rates. The objective of(More)
Ultrasound characterization of erythrocyte aggregation (EA) is attractive because it is a non-invasive imaging modality that can be applied in vivo and in situ. An experimental validation of the Structure Factor Size Estimator (SFSE), a non-Rayleigh scattering model adapted for dense suspensions, was performed on 4 erythrocyte preparations with different(More)
Micro particle image velocimetry (µPIV) is a common method to assess flow behavior in blood microvessels in vitro as well as in vivo. The use of red blood cells (RBCs) as tracer particles, as generally considered in vivo, creates a large depth of correlation (DOC), even as large as the vessel itself, which decreases the accuracy of the method. The(More)
3D-ultrasound (US) imaging systems offer many advantages such as convenience, low operative costs and multiple scanning options. Most 3D-US freehand tracking systems are not optimally adapted for the quantification of lower limb arterial stenoses because their performance depends on the scanning length, on ferro-magnetic interferences or because they(More)
OBJECTIVES In many pathological conditions, including high-risk surgery, the severity of the inflammatory response is related to the patient outcome. However, determining the patient inflammatory state presents difficulties, as markers are obtained intermittently through blood testing with long delay. RBC aggregation is a surrogate marker of inflammation(More)
Multimodality vascular flow phantoms provide a way of testing the geometric accuracy of clinical scanners and optimizing acquisition protocols with easy reproducibility of experimental conditions. This article presents a stereolithography method combined with a lost-material casting technique that eliminates metal residues of cerrolow (a low temperature(More)
Color Doppler imaging is an established pulsed ultrasound technique to visualize blood flow non-invasively. High-frame-rate (ultrafast) color Doppler, by emissions of plane or circular wavefronts, allows severalfold increase in frame rates. Conventional and ultrafast color Doppler are both limited by the range-velocity dilemma, which may result in velocity(More)
The aim of this study was to evaluate the effect of the depth of correlation (DOC) on the cross-correlation method (CC) applied to microcirculatory blood flow in vitro. The cross-correlation algorithm was optimized to compute red blood cell velocity profiles in tube flow. Flow rates, estimated by computing the circular integral of mean velocity profiles,(More)