The CT Scanner

The CT scanner is a large square machine with a hole in the centre.  The patient lies still on a table that can move up or down, and slide into and out from the centre of the hole.  Within the machine an x-ray tube rotates around the patients body to produce the images. 

As with x-rays, very small controlled amounts of radiation are passed through the body.  The resulting images are then reconstructed by a computer into two-dimensional images of the sections that were scanned.  This enables a very detailed, multidimensional view of the body’s interior.

Spiral or helical CT allows faster, higher-quality images with less radiation exposure.

What does a CT scan feel like?

CT scanning is painless.  For some examinations of the abdomen you may be required to drink a contrast material prior to the examination.  Other examinations may require an injection of intravenous contrast.  You may be asked to refrain from eating or drinking anything for up to four hours prior to your examination.  Other examinations require no preparation at all.  You will be alone in the room during the examination, although the Technologist will be able to see and speak to you.

CT Scanning of the Abdomen

CT imaging of the lower gastro-intestinal (GI) tract can be used to accurately diagnose many causes of abdominal pain such as an abscess in the abdomen, inflamed colon or colon cancer, diverticulitis and appendicitis.  CT is often the preferred method for diagnosing many different types of cancer, since it can confirm the presence of a tumour, measure it’s size, precise location and the extent of the tumours involvement with nearby tissue.  CT examinations can also be used to plan and administer radiotherapy treatments for cancers, and to guide biopsies.

CT Scanning of the Head

CT can assist in locating skull fractures and brain damage in patients with head injuries.  It may be used to detect a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke or in a patient with sudden severe headache who may have a ruptured or leaking aneurysm.  CT is used to detect some brain tumours.  CT is useful to determine whether inflammation or other changes are present in the paranasal sinuses.