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P0399
High Frame Rate Blood Flow Imaging by Visualization of Ultrasonic Echoes from Blood Particles in Echocardiography
Hiroki Takahashi, Hideyuki Hasegawa and Hiroshi Kanai
Graduate School of Engineering, Tohoku University, 6-6-05 Aramaki-aza-Aoba Aoba-ku, Sendai,
Miyagi 980-8579, Japan.
ABSTRACT
Blood flow imaging in echocardiography is useful to evaluate the pumping function of the human heart. In the present study, we proposed a non-invasive method for cardiac blood flow imaging by visualization of echo speckles of blood particles. Coded excitation and pulse compression were used to increase Signal-to-Noise Ratios (SNRs) of weak echoes from blood particles and to improve the penetration of transmitted pulse without a safety violation. In in vivo measurement, ultrasonic RF echo signals from the human heart were measured at very high frame rate of 947 Hz by parallel receive beamforming with plane wave transmission in three chamber view of a 25-year-old healthy male. Each excitation was coded with Barker code sequence. Beamformed RF signals were compressed by matched filtering. Beamformed RF signals with pulse compression were high pass filtered in the direction of frame to enhance echoes from blood particles and suppress echoes from slowly moving tissues. Motions of echoes from blood particles, which showed speckle-like pattern, could be visualized inside the left ventricle. The in vivo experimental result shows a potential of non-invasive imaging of blood flow pattern at high temporal and spatial resolution using our proposed method.
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P0399