Ultrasound uses nonionizing (no radiation), high-frequency sound waves to generate a real time image of a particular structure. While x-ray is important in the visualization of bony structures, in the visualization of soft tissue masses, internal body organs and muscles, ultrasound is used for the treatment and diagnosis of many medical conditions.

A "Doppler" technique can also be used to visualize blood flowing through blood vessels (arteries and veins). The ultrasound technologist will apply a hand-held transducer directly to the patient's skin while performing the examination to create the visualization of the affected body part.