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CT Scan

What is a CT scan?  

A CT scan or CAT (Computerised Tomography or Computerised Axial Tomography) is an X-ray examination which uses a specialised scanner to obtain cross sectional images through the body and computer processing reconstructs the images. This information may help your consultant with diagnosis and planning of your treatment.

What happens during the scan?

  • You may be asked to change into a gown by a member of staff depending on which part of your body is to be examined.
  • You will then be taken into the CT room and positioned into the scanner.
  • The area to be scanned will be positioned within the machine and you will be asked not to move.
  • We will make you comfortable and answer any queries you may have.
  • The scan will then be undertaken.

The scanner consists of a ring that rotates around a small section of your body as you pass through it. The radiographer will be able to see and speak to you throughout the examination and the length of the examination will vary depending on which area is being looked at.

You can expect to be in the X-ray Department for up to one hour. Many examinations are however completed sooner than this and take approximately 10 to 20 minutes.

What happens after the scan?

You should be able to go home or back to work after the examination. Your scan results will not be available immediately. A computer will reconstruct the information from your scan which will be analysed by a Radiologist (a doctor who is a specialist in interpreting images). The Radiologist will write a report which will be accessed by the Consultant, Doctor or Allied Health professional who referred you for the scan, this will allow them to discuss the results with you. This normally takes between a few days or weeks.

Important note

It is important that you inform the department as soon as possible if you are pregnant, or suspect you may be pregnant, please call 0121 685 4135.

Known risks

The use of ionizing radiation will be kept to a minimum. However, CT is regarded as higher than conventional X-ray. Generally, the amount of radiation you are exposed to during each CT scan is equivalent to between a few months to a few years of background radiation which occurs naturally. It is thought exposure to radiation during a CT scan could slightly increase your chance of developing cancer many years later, although the risk is thought to be very small (less than 1 in 2000). More information is available on patient dose information:

The benefits and risks of having a CT scan will be weighed up by the referrer before it is recommended. Occasionally, some examinations require the use of a contrast agent (x-ray dye) to demonstrate some structures, the use of contrast carries a very small risk of reaction: the incidence of severe reaction with non-ionic agents is 0.04% and very serious reaction is 0.004% (Royal College of Radiologists figures). Please let the Department know if you have any allergies. This dye will be given through an intravenous cannula which will be inserted by the radiographers prior to the scan and removed after the examination.

More information

Imaging Appointments - 0121 685 4135

The Royal Orthopaedic Hospital | T: 0121 685 4000 |