Signal Processing Methods for Transmission Ultrasonic Computerized Tomography

Measurements required for ultrasonic computer assisted tomography are time-of flight of the signal and its amplitude. Images reconstructed from attenuation data obtained from pulses, bursts, and chirps are presented. Clinical results are described in which some characteristics of breast cancer are shown to be 1) relatively increased acoustic speed with, 2) lower internal attenuation, and 3) a ring of higher attenuation surrounding the lesion. A design for a clinical scanner is described in which images of eight planes in each breast can be obtained in a few minutes.