Diagnostic ultrasound, also called sonography or diagnostic medical sonography, is an imaging method that uses sound waves to produce images of structures within your body. The images can provide valuable information for diagnosing and directing treatment for a variety of diseases and conditions.
Most ultrasound examinations are done using an ultrasound device outside your body, though some involve placing a small device inside your body.
Ultrasound is used for many reasons, including to:
Diagnostic ultrasound is a safe procedure that uses low-power sound waves. There are no known risks.
Ultrasound is a valuable tool, but it has limitations. Sound waves don't travel well through air or bone, so ultrasound isn't effective at imaging body parts that have gas in them or are hidden by bone, such as the lungs or head. Ultrasound may also be unable to see objects that are located very deep in the human body. To view these areas, your health care provider may order other imaging tests, such as CT or MRI scans or X-rays.
Most ultrasound exams require no preparation. However, there are a few exceptions:
Wear loose clothing to your ultrasound appointment. You may be asked to remove jewelry during your ultrasound, so it's a good idea to leave any valuables at home.