Ultrasound

Diagnostic ultrasounds use sound waves to make pictures of the body. Ultrasound, also called sonography, shows the structures inside the body. The images can help guide diagnosis and treatment for many diseases and conditions. Most ultrasounds are done using a device outside the body. However, some involve placing a small device inside the body.

Ultrasound is used for many reasons, including to: View the uterus and ovaries during pregnancy and monitor the developing baby's health. Diagnose gallbladder disease. Evaluate blood flow. Guide a needle for biopsy or tumor treatment. Examine a breast lump. Check the thyroid gland. Find genital and prostate problems. Assess joint inflammation, called synovitis. Evaluate metabolic bone disease.

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. This means 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 also may not be able to see objects that are located very deep in the human body. To view these areas, your healthcare professional 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: For some scans, such as a gallbladder ultrasound, your healthcare professional may ask that you not eat or drink for a certain period of time before the exam. Other scans, such as a pelvic ultrasound, may require a full bladder. Your healthcare professional will let you know how much water you need to drink before the exam. Do not urinate until the exam is done. Young children may need additional preparation. When scheduling an ultrasound for yourself or your child, ask your healthcare professional if there are any specific instructions you'll need to follow.