W054004 超音波を用いた心臓内血流ベクトルの可視化技術 : Vector Flow Mappingについて([W05400]流体工学部門,バイオエンジニアリング部門企画,血液の視える化研究(血視研))

Abstract

A fundamental algorithm for vector flow mapping (VFM) is reviewed. VFM is an echocardiographic approach for non-invasively visualizing two-dimensional blood flows. The VFM algorithm applies the fluid mass-conservation law, namely, a continuity equation, to color-Doppler flow mapping (CFM) in order to estimate azimuth velocities under the assumption that the flows are two-dimensional in the imaged plane. When the VFM integrates the continuity equation in the azimuth direction in the left ventricle (LV), it requires a boundary condition (BC). A tissue-tracking technique acquires heart-wall velocities at both ends of an integration path. The VFM algorithm calculates the azimuth velocities by introducing a weighted function to impose the no-slip condition on both ends, and VFM vector fields are obtained by using the Doppler velocities and the azimuth velocities. The obtained VFM vector field will make it easier to diagnose cardiac abnormalities.