Ultrasound imaging involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Small pulses of inaudible, high-frequency sound waves bounce off of internal organs, fluids and tissues and a microphone records tiny changes in the sound's pitch and direction. These sound wave changes are instantly measured and displayed by a computer, which in turn creates a real-time picture on the monitor. Because ultrasound images are captured in real-time, they can show the structure and movement of the body's internal organs, as well as blood flowing through blood vessels.
A clear gel is applied to the area of the body being studied to help the transducer make secure contact with the body and eliminate air pockets between the transducer and the skin. The ultrasound technologist or radiologist then presses the transducer firmly against the skin and sweeps it back and forth over the area of interest. A nearby screen will show the ultrasound image which is created based on the strength, frequency and time it takes for the sound signal to return from the patient to the transducer.