Adaptive diagnostic ultrasonic imaging

Abstract

Medical ultrasonic imaging systems assume a constant, fixed acoustic propagation velocity in tissue. This assumption allows the focusing of ultrasonic pulses in a simple way with transducer arrays with electronic delay lines. However, soft tissue acoustic velocities actually range from 1350 m/s to 1725 m/s, and the basic focusing procedure fails to obtain high quality images on some patients. Here we describe different adaptive techniques that allow focusing through such inhomogeneous tissues.