Computed Tomography (CT) Scan

What is a CT scan?

A CT scan uses radiation (X-rays) and a computer to make detailed pictures of the inside of your body.

A traditional CT scanner is a large, donut-shaped machine. It has a short tunnel in the centre. You will be asked to lie on a table that then slides into the short tunnel.

It is usually used to see if your prostate cancer has spread to other parts of the body, e.g. lymph nodes. You find lymph nodes all around your body. They are part of the immune system.
CT scans are not as useful as magnetic resonance imaging (MRI) scans for looking at the inside of your prostate.

Frequently asked questions (FAQs) about CT scans

What happens before the CT scan?

What do I need to do?
You should get an appointment letter that will tell you what you need to do before the scan. Before you have the scan, tell the radiographer or your doctor if you:
- Have any allergies
- Have kidney problems
- Are taking medication for diabetes.
Special arrangements may have to be made.
You may:
Be asked avoid eating anything for a few hours before your scan.
Be able to wear your own clothes during the scan. It is best to wear something loose and comfortable. Some hospitals will ask you to wear a gown.
You will be asked to avoid wearing:
Jewellery
Clothes that contain metal buttons or zips.
Contrast medium
You may be given a special dye called a contrast medium.
This may be given as a drink or as an injection into your vein. This will give a clearer picture of the inside of your body.
The injection is given through a small tube in the vein on the back of your hand or your arm. This is called a cannula. The radiographer will use this to inject the dye.

What happens when you have a CT scan?

The bed will pass into the scanner.
You may see some lights projected onto your body. These make sure that you are in the right position.
You may also hear some clicks and buzzing sounds.
The radiographer will ask you to lie really still and breathe normally. They may ask you to breathe in or out or hold your breath at some points. The scan takes about 20–30 minutes.

When will I get my test results?

Your test results may take one-to-two weeks to come back. You may have a follow-up appointment with your doctor. They will tell you your results.

This information was published in March 2023. We will revise it in March 2024.
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