CT

What is a CT Scan?

CT ( computed tomography), sometimes called CAT scan, uses special x-ray equipment to obtain image data from different angles around the body and then uses computer processing of the information to show a cross-section of body tissues and organs.

CT imaging is particularly useful because it can show several types of tissue - lung, bone, soft tissue and blood vessels - with great clarity. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.

Common uses of the CT Procedure

CT is one of the best tools for studying the chest and abdomen as it provides detailed, cross sectional views of all types of tissue.

It is often the preferred method for diagnosing many different cancers since the image allows a physician to confirm the presence of a tumor and measure its size, precise location and the extent of the tumors involvement with other near tissues.

CT Procedure

CT scanning causes no pain but it does involve exposure to radiation in the form of x-rays, but the benefit of an accurate diagnosis far outweighs the risk. For different parts of the body the patient preparation will be different. You may be asked to swallow either water or a positive contrast material, a liquid that allows the radiologist to better see the stomach, small bowel and colon.

An injection of an intravenous contrast (injected into a vein in the arm) is needed for some scans to help to highlight and differentiate different parts of the body.

The CT scanner is a large, square machine with a hole in the center, often described as a large doughnut or Polo mint. 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 in a rotating gantry moves around the patient’s body to produce the images, making clicking and whirring noises as the table moves.

How should I prepare for a CT scan?

Comfortable, loose fitting clothing should be worn for your CT exam. Metal objects can affect the image, so avoid clothing with zippers and snaps. You may be asked to remove hairpins, jewellery, eyeglasses, hearing aides and any removable dental work, depending on the part of the body that is being scanned.

You may be asked not to eat or drink anything for one or more hours before the exam. Women should always inform their doctor if there is any possibility that they are pregnant.

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