CT Scan | Infopool

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?

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. For example, if you are taking metformin, you will be advised not to take this before your scan.

Discuss this with your healthcare team before you go for your scan.

Be asked to 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:

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.
The results may take longer if you are having other scans.

This information was updated in June 2024. Date of next review: June 2026.
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