A CT (Computerised Tomography) scan is a specialised X-Ray examination, which gives clear images of the inside of your body. CT is excellent in showing soft tissue, air, fluid, bone, vessels and all other internal structures of the body, allowing your doctor to identify any problems. New technology allows CT to be painless, stress free and very fast: often we can scan neck to pelvis in one breath hold.
Some CT scans use a 'contrast agent' (a dye containing iodine) which can be a drink or injection - this is used to enhance the image and give a clear view of your condition.
For more information on CT scans, please download our CT scan patient information leaflet
Your appointment confirmation letter will provide you with instructions regarding eating, drinking and taking medication before your appointment - it is very important that these instructions are followed. If you have any queries or need advice please contact us on the number provided in your confirmation letter or by contacting the unit (find the contact details of your centre here).
For a CT scan involving a 'contrast injection' you should fast for four hours prior to your appointment. You will be told at the time of booking if your scan requires a contrast injection, or if you need to have liquid preparation. Your appointment time should include the time needed to drink the liquid preparation and it may be up to an hour before your scan is carried out.
If you could be pregnant or are in the first six months of pregnancy, please let us know.
If you are diabetic and taking 'Metformin', please advise the radiographer when you book for your scan, as there are some post-procedure care instructions we must go through with you.
If you need help because you speak a different language, please let us know when you book your appointment.
If you are female and feel you would need a chaperone, you can bring a friend or relative with you.
On arrival one of our staff will explain the procedure to you, run through a simple safety questionnaire to make sure you can be scanned and answer any further questions you may have.
If your scan requires a contrast agent, you will be given a drink or injection containing the agent and asked to wait for an hour before your scan. The contrast agent is safe and will cause no after-effects. Shortly after the injection, you may feel a warming sensation throughout the body and sometimes this feeling is more pronounced in the pelvic area.
The radiographer will then take you into the scanner room. The CT scanner looks like a big ring called a gantry and is open at both ends with a table that slides very quickly through the middle.
Whilst it is not necessary to undress for the scan, please note that all clothing containing metal will need to be removed, including underwear containing metal. It may also be advisable to wear loose baggy clothing e.g. tracksuit bottoms, t-shirt, sweatshirt etc. It can sometimes become cold in the scanner, so it may be advisable to wear socks.
The Radiographer will take you into the scanner room and make sure that you are comfortably positioned on the scanner bed. During scanning we may ask you to keep still or hold your breath at certain times. This is to ensure that the scanner can get a good, clear image. The scan is completely painless; all you will hear are some mechanical sounds from the scanner.
During the entire examination, the radiographer can see you clearly and speak to you via a two-way intercom - so if you have any problems, you only have to speak.
When completed, the results will be interpreted by a consultant radiologist and forwarded to your referring doctor.
I am claustrophobic - might the CT scanner cause me a problem?
As the scanner is open plan and the imaging time very short, claustrophobia is rarely a problem.
What is the radiation dose from a CT Scan?
Following guidelines set out in the Ionising Radiation (Medical Exposure) Regulations (IRMER) 2000, exposure to ionising radiation should be kept to a minimum whenever possible. In all cases, the clinician who refers you for a CT scan will ensure that the benefits provided by the information in the examination outweigh the risks associated with the radiation dose.
How long does the CT Scan take?
The actual scanning itself depends on the type of scan, but can be as short as a breath hold, from 5-10 seconds. The total length of a CT scan procedure can be between approximately 20 minutes to an hour, depending upon the type of examination, the preparation and postexamination processing.