Ultrasound imaging

Examines internal organs and soft tissue, as well as assessing blood flow to diagnose or monitor conditions.

What is an ultrasound scan?

High-frequency sound waves are used to create images of the inside of the body during an ultrasound scan (also called a sonogram).

As sound waves bounce off your body's tissues, the ultrasound probe detects these echoes. By sending this information to a computer, real-time moving images are generated. Ultrasounds are sound waves that are beyond the range of human hearing - you cannot hear them.

Sound waves are measured by their frequency, which is measured in Hertz. Diagnostic ultrasound scans usually take place at a frequency of 2-18 Hertz. Higher frequencies produce better quality images but they are also absorbed by your skin and other tissues. This means high-frequency sound waves can’t create images of tissues deep inside your body. A lower frequency passes deeper into your body, so it can create images of tissues deep within, but the images are of poorer quality.

Ultrasound scans are usually performed by radiologists or sonographers (people trained in ultrasound scanning), who also analyse the results.

What are the benefits of an ultrasound?

Handheld ultrasound sensors, which look like microphones, are designed to deliver ultrasound waves. There is no radiation involved in the procedure, so it is considered completely safe. The procedure is used to diagnose congenital heart disease, and to examine the prostate gland, the uterus, and the ovaries, among other organs. Biopsies are also performed using ultrasound.

How does an ultrasound work?

A consultant radiologist performs the examination, which usually takes fifteen to thirty minutes. You will be asked to lie down on a couch. Some gel will be applied to your body to enable the sensor, which is passed over your skin, to pick up sound waves and an image is produced of the part of the body being scanned. If you are, or there is a possibility you may be, pregnant please tell the radiographer before your scan.

Continue taking your normal medication unless you are told otherwise. If you are diabetic please tell the radiology department. For some procedures, you may be asked to fill your bladder by drinking plenty of water. For other procedures, you may be asked not to eat or drink anything for up to four hours before the test. The Imaging Team will give you advice when booking your appointment.