Lateral Velocity Profile and Volume Flow Measurements Via 2-D Speckle Tracking

Abstract

Current Doppler-based techniques for measuring velocity profiles and volume flow rates are plagued by inaccuracies due to errors in estimating the direction of flow with respect to the transducer axis. In addition, such techniques are incapable of quantifying lateral flow. We describe a system which tracks 2-D ultrasonic speckle patterns in order to quantify both the axial and lateral components of motion, thereby obviating the need for angle estimation. The method involves tracking the motion of small regions of an image from one acoustic interrogation to the next using a time-domain pattern matching algorithm. We report on the ability of this system to measure laminar flow velocity profiles and volume flow rates in a laterally flowing phantom. Results indicate that the technique provides accurate velocity and volume flow estimates over a wide range of flow rates.