CT scan

Preparing for your CT scan

You should plan to be in the CT department for up to 2 hours.

Sometimes we'll ask you not to eat or drink before your scan. The administration staff will let you know about this and your appointment letter will tell you how long before the scan to stop.

If you're asked to drink before your scan, you should slowly drink 500ml of water (about 2 glasses) over 1 hour leading up to your appointment time.

If you are taking medicines, continue to take them unless you have been told not to by your doctor.

We do not have childcare facilities. Please do not bring children or dependants with you.

Please be ready to remove:

  • any head coverings, hairbands, grips and earrings if we're scanning your head
  • remove any metallic dentures or hearing aids for certain scans, dental fillings will not affect the scan

Do not

  • wear clothes with metal fastenings like zips or poppers, or we might ask you to change into a hospital gown

Having an injection before your scan

If we're scanning certain areas of your body, we might need to give you an injection of X-ray contrast.

The X-ray contrast shows up on the scan to give a more detailed picture.

The injection will be given by putting a small needle into a vein in your arm or hand.

The contrast might give you a metallic taste in your mouth and a warmth in your body, or 'hot flush'. Some people feel like they have peed. Don't worry, you won't. It just gives that sensation.

All these sensations pass in a couple of minutes.  

If you need X-ray contrast, there's a small risk you could have an allergic reaction.

Before having the injection, you should let staff know if you:

  • have a history of allergic reactions
  • have blood clotting problems
  • are pregnant, or think you could be

For more information, ask the radiographer before your scan or visit the NHS website.

During your CT scan

A trained specialist called a radiographer will do your CT scan.

The radiographer will ask you to confirm some details, including your name.

Usually the scan takes 10 to 20 minutes.

The scanner is a large ring shape, like a doughnut.

We'll ask you to lie down on a bed. We might use straps and pillows to help get you into the right position. Once you are in position, we'll move you slowly into the centre of the ring.

You should not feel any pain during the scan.

You'll need to lie very still while each picture is taken. If you move, the images might be blurred. We might ask you to hold your breath at times.

The images are recorded and the radiographer will check them to make sure they can be used.

When the scan is finished, you can get off of the scanner bed and leave the scanning room.

After your CT scan

As soon as the scan is finished, you can leave the hospital or return to the ward.

You can eat and drink as usual, and do your usual activities.

If you have had an X-ray contrast injection, we might ask you to wait for 10 minutes before you leave the department. This is to make sure you are feeling OK and there is no sign of allergic reaction to the contrast.

A mild delayed allergic reaction can happen up to 2 days after the scan. If you think you are having a delayed allergic reaction (typically hives) contact your GP for advice.

Out of hours, please go to your nearest emergency department (A&E).

Getting your results

Your CT images will be studied by a consultant radiologist. The results will be sent to the health professional who referred you to the radiology department.

They will discuss the results with you and any treatment you might need.

Please allow 2 weeks for the results to be sent to the doctor who referred you.

If you are staying in hospital you may get your results sooner. The results will be given to the doctors looking after you on the ward.

Last updated: September 2023

Contact us

For more information, please contact us.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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