CT scan

What is a CT scan?

A CT scan uses pictures (x-rays) to build up a 3D picture of the inside of your body. CT stands for computerised tomography.

Why do I need to have this scan?

Doctors might use a CT scan to show:

  • if a lump or abnormal area is cancer or not
  • the size of a cancer and if it has spread
  • how well cancer treatment is working.

What happens?

Before the scan

The hospital gives you information about the scan so you know what to expect. Sometimes they may ask you not to eat or drink for a few hours before the scan. This helps to make sure they get a clear picture.

If there is any chance you could be pregnant, it is important that you tell your doctor, nurse or the person doing the scan (radiographer).

On the day of the scan, the radiographer will explain what will happen. You can ask them any questions you have. They will ask you to remove all jewellery and metal before the scan. They might also ask you to change into a gown.

You may need to drink a dye called contrast. This is sometimes given as an injection. The dye makes parts of your body show up more clearly on the scan. This can sometimes make you feel hot all over for a few minutes.

After you drink the dye, they put an injection into you and you get this kind of funny warm feeling.


During the scan

The CT scanner looks a bit like a giant doughnut, with a narrow bed that goes through the middle.

The scan is not painful, but lying still on the bed during the scan can be a bit uncomfortable. It usually takes between 5 and 15 minutes.

The radiographer leaves the room during the scan, but can see you through a screen. You can talk to them through an intercom while you are having the scan.

During the scan, the bed moves slowly through the middle of the scanner while the camera takes the pictures (x-rays).

Being positioned for a CT scan
Being positioned for a CT scan

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You get passed through this kind of big round doughnut. You lie down on a bench and it passes you through slowly.


After the scan

You can usually go home straight after the scan.

Any test using radiation can slightly increase your risk of developing a cancer when you are older. However, this is not common, and the risk is very small compared to the benefit of having the test. Your doctor can tell you more about this.

It can take from a few days up to a couple of weeks to get the results. Waiting for test results can be a worrying time. Talking to your family and friends about how you feel can help. You can also speak to your doctor or nurse if you have any problems, or need more support.