What you will experince during a CAT Scan

Scanning itself causes no pain. You may be asked to remain still for a few minutes. (If you have a hard time staying still, are claustrophobic or have chronic pain, then a sedative may be offeredby your referring physician to assist.

You may be asked to hold your breath during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This is similar to the blurring seen on a photograph taken of a moving object.

If an intravenous contrast material is used:


  • A slight pin prick when the needle is inserted into your vein.
  • A warm, flushed sensation during the injection of the contrast materials.
  • Metallic taste in your mouth that lasts for a few minutes.
  • You may experience a sensation like they have to urinate but this subsides quickly.

Most patients experience none of these sensations


  • Fruit flavoured oral contrast


  • A small amount of contrast is introduced per rectum. This affords enhanced visualization of the lower end of the colon and rectum.
  • You may experience mild abdominal fullness or a need to expel the liquid

Be patient, as the mild discomfort will not last long.

You should inform your physician of any medications you are taking and if you have any allergies. If you have a known allergy to contrast material, or “dye,” your doctor may prescribe medications to reduce the risk of an allergic reaction.

With modern CT scanners, you will hear only slight buzzing, clicking and whirring sounds as the CT scanner revolves around you during the imaging process.

You will be alone in the exam room during the CT scan. However, the technologist will be able to see, hear and speak with you at all times.

With pediatric patients, a parent may be allowed in the room but will be required to wear a lead apron to prevent radiation exposure.

After a CT exam, you can return to your normal activities. If you received contrast material, you may be given special instructions.