Ultrasounds are visual representations of body parts, tissues, or organs, using high frequency sound waves instead of radiation. A lightweight transducer, or sound machine, is placed on the skin over the part to be examined and produces sound waves that penetrate the skin to reach tissues and organs. When the sound waves strike specific tissue surface, echoes are produced. The echoes are detected by the transducer and electronically converted into an image displayed on a video screen.

Common examples of ultrasound diagnostic imaging include cardiac stress tests, breast ultrasounds, and sonographs for pregnant women.