Flow Characteristics in Poststenotic Regions of the Human Coronary Artery Assessed by 20-MHz 80-Channel Pulsed Doppler Velocimetry

Abstract

A detailed assessment of flow dynamics in coronary stenosis is essential for better understanding of the pathophysiology of the obstructive coronary artery disease. However, measurements of phasic blood flow velocity and velocity distribution in a native human coronary artery have been hampered by methodological limitations. The ultrasound pulsed Doppler method is useful for measuring local blood flow velocity in vessels noninvasively. However, a conventional single-channel pulsed Doppler velocimeter with low carrier frequencies cannot obtain detailed blood velocity profiles of small vessels like the coronary artery. Recently, we have developed an 80-channel 20-MHz pulsed Doppler velocimeter [1-3], which detects Doppler signals from 80 channels by a zero-cross method and analyzes Doppler signals from one optional channel by a fast Fourier transform method, both in real time.