Diagnostic Imaging

An ultrasound scan, sometimes called a sonogram, is a procedure that uses high-frequency sound waves to create an image of the inside of the body.

Ultrasound scans do not use any radiation. A small device called an ultrasound probe is used, which gives off high-frequency sound waves. You can’t hear these sound waves, but when they bounce off different parts of the body, they create “echoes” that are picked up by the probe and turned into a moving image. This image is displayed on a monitor while the scan is carried out.

Before having some types of ultrasound scan, you may be asked to follow certain instructions to help improve the quality of the images produced.

For example, you may be advised to:

• drink water and not go to the toilet until after the scan – this may be needed before a scan of your pelvic area
• avoid eating or drinking for several hours before the scan – this may be needed before a scan of your digestive system, including the liver and gallbladder

External ultrasound

A small handheld probe is placed on your skin and moved over part of your body being examined. A thin layer of gel is put on your skin to allow the probe to move smoothly. This also ensures there’s continuous contact between the probe and the skin.

Internal ultrasound scan

An internal examination allows a doctor to look more closely inside the body at organs such as the prostate gland, ovaries or womb.

Endoscopic ultrasound scan

During an endoscopic ultrasound scan, an endoscope is inserted into your body, usually through your mouth, to examine areas such as your stomach or food pipe (oesophagus).

You’ll usually be asked to lie on your side as the endoscope is carefully pushed down towards your stomach.

The endoscope has a light and an ultrasound device on the end. Once it’s been inserted into the body, sound waves are used to create images in the same way as an external ultrasound.

You’ll usually be given a sedative to keep you calm and local anaesthetic spray to numb your throat, as an endoscopic ultrasound scan can be uncomfortable and may make you feel sick.

You may also be given a mouth guard to keep your mouth open and protect your teeth, in case you bite the endoscope.

Magnetic Resonance Imaging (MRI) uses a strong magnet fields and radio waves to produce detailed images of the inside of the body. It is particularly useful for brain, spine and musculoskeletal imaging. The scanner uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.

As the MRI scanner produces strong magnetic fields, it’s important to remove any metal objects from your body.

These include:

• watches
• jewellery, such as rings and necklaces
• piercings, such as ear, nipple and nose rings
• dentures (false teeth)
• hearing aids
• wigs (some wigs contain traces of metal)

The MRI scanner is a large tube with a table attached to it. You’ll be asked to lie on the table and a lab assistant or technician will help you into a comfortable position and explain what you can expect during the scan. When you’re ready, the table will slide into the scanner. Depending on the part of your body being scanned, you’ll be moved into the scanner either head first or feet first. It’s very important to keep as still as possible during your MRI scan.

You will be given a buzzer to hold. You’ll be able to talk to the radiographer through an intercom and they’ll be able to see you on a television monitor and through the viewing window throughout the scan..

You will also be given earplugs or headphones to protect your ears, as the MRI scanner can be noisy.