What are ultrasound scans?

Ultrasound scans are images of the internal organs created from sound waves. The images are produced when the sound waves are directed into the body then reflected back to a scanner that measures them.

What are ultrasound scans used for?

Ultrasound scanning is used to help monitor and diagnose conditions in many parts of the body, including the kidneys, the liver and the heart. It is often used to examine conditions affecting the organs in a woman's pelvis - the uterus, Fallopian tubes and ovaries. Ultrasound scanning is not dangerous and has no side effects, so it is safe to use during pregnancy.

How does an ultrasound work?

The ultrasound scanner looks like a small paint roller. As it moves back and forth over the body, it sends sound waves through the skin and muscles. These waves are then turned into an image that appears on a TV screen. The scan can also be copied onto paper or X-ray film.

How is an ultrasound scan performed?

The way the ultrasound scan is performed depends on the purpose of the examination. The scanner can be used externally on the skin, or through the natural openings of the body, such as the vagina.

For example, if the kidneys or liver are being examined the patient will be told to lie on their back or side on an examination table. Some special gel is spread over the skin, enabling the scan to define the organs as clearly as possible.

However, if a woman's pelvic organs are under examination, a transvaginal scan would provide a better picture. A small probe is gently inserted into the vagina up to the cervix to get the best image. It should not cause more than a slight discomfort.

Does an ultrasound scan hurt?

An ultrasound scan does not hurt but the gel used for the examination can feel a bit cold.

Where are ultrasound scans performed?

The examination has traditionally taken place in hospital, with patients being referred by their GP or midwife. However, ultrasound is available in a small but growing number of doctors' surgeries.