An ultrasound scan, also referred to as a sonogram, diagnostic sonography, and Ultrasonography, is a device that uses high frequency sound waves to create an image of some part of the inside of the body, such as the stomach, liver, heart, tendons, muscles, joints and blood vessels. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz. An instrument called a transducer emits high-frequency sound, inaudible to human ears, and then records the echoes as the sound waves bounce back to determine the size, shape, and consistency of soft tissues and organs. This information is relayed in real time to produce images on a computer screen. Ultrasound technicians, or sonographers, have special training in how to perform the test. Then a radiologist or your doctor will interpret the ultrasound images. This technology can help diagnose and treat certain conditions.