Medical Ultrasonics: Diagnostic Applications of Ultrasound

Current research on the use of low-power ultrasound as a diagnostic tool is reviewed. Ultrasonic waves can be used to investigate soft tissue structures which are opaque to light or invisible to X rays. Continuous-wave techniques can picture absorbing or reflecting areas in tissue specimens. Doppler frequencies related to the motion of the heart have also been investigated. Pulse reflection techniques can detect the small echoes reflected from interfaces between and within tissue structures. Radar scanning tecnhiques are used to form reflection pictures of accessible tissues. The significance of such pictures of the breast, bowel, eye, extremities, kidney, liver, and neck areas in the living human is being studied. The position and velocity of the walls of the heart during the cardiac cycle also can be recorded.