Institute of Fundamental Technological Research

Complex flow patterns are prevalent in the vasculature, but they are difficult to image non-invasively in real-time. This paper presents the first real-time scanning platform for a high frame rate ultrasound technique called color encoded speckle imaging (CESI) and its use in visualizing arterial flow dynamics in-vivo. CESI works by simultaneously rendering flow speckles and color-coded flow velocity estimates on a time-resolved basis. Its live implementation was achieved by integrating a 192-channel programmable ultrasound front-end module, a 4.8 GB/s capacity data streaming link, and a series of computing kernels implemented on the graphical processing unit (GPU) for beamforming and Doppler processing. A slow-motion replay mode was also included to offer coherent visualization of CESI frames acquired at high frame rate (3,000 fps in our experiments). The live CESI scanning platform was found to be effective in facilitating real-time image guidance (at least 20 fps for live video display with 55 fps GPU processing throughout). In vivo pilot trials also showed that live CESI, when running in replay mode, can temporally resolve triphasic flow at the brachial bifurcation and can reveal flow dynamics in the brachial vein during a fist-clenching maneuver. Overall, live CESI has potential for use in routine investigations in-vivo that seek to identify complex flow dynamics in real-time and relate these dynamics to vascular physiology.

color-encoded speckle imaging (CESI), complex flow visualization, graphical processing units (GPUs), high-frame-rate ultrasound (HiFRUS), in vivo studies, live scanning platform