Ultrasound

An ultrasound, sometimes called a sonogram, is a scan that uses high-frequency sound waves to produce moving images of the inside of the body. A small device sends sound waves that bounce off tissues and return as echoes, which a computer turns into pictures. Because it uses no ionising radiation, ultrasound is considered very safe and can be repeated as often as needed.

Ultrasound is used to look at many soft tissues and organs, including the heart, liver, kidneys, and blood vessels, and to check the health and growth of a baby during pregnancy. It can help diagnose problems, guide procedures such as taking a tissue sample, and monitor blood flow. Its safety and real-time images make it useful in a wide range of situations.

Preparation depends on the part of the body being scanned. For some abdominal scans you may be asked not to eat for several hours, while for pelvic or pregnancy scans you may need a full bladder, so you will be told to drink water beforehand and not empty your bladder. For many other scans, no special preparation is needed at all.

You usually lie down while a clear gel is applied to your skin to help the sound waves travel. The operator, called a sonographer, moves a smooth handheld probe over the area, watching the images appear on a screen. The scan is painless, though there may be slight pressure, and it typically takes 15 to 45 minutes. Some scans use an internal probe for clearer images.

After an ultrasound you can wipe off the gel and return to normal activities immediately. Sometimes the sonographer can share initial findings on the day, but a full report is usually prepared for your doctor. The results may show how an organ looks, how blood is flowing, or how a pregnancy is developing, and your doctor will explain what they mean and whether any further steps are needed.