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Virtual Colonoscopy
Definition:
Virtual colonoscopy (VC) combines MRI or CT scans with sophisticated computer software to produce images of the colon and rectum. The test, which is less invasive than conventional colonoscopy, detects polyps in the colon.Alternative Names:
Colonoscopy - virtual Text Continues Below
How the test is performed:
Patients must follow a strict bowel-emptying procedure the day before, just as they would for a standard colonoscopy. The test is performed in the radiology department of a hospital or medical center. Unlike conventional colonoscopy, no sedatives are needed and no scope is used. You will lie down on your left side on a narrow table that is connected to an MRI or CT machine. Your knees will be up toward your chest. A small, flexible tube will be inserted into your rectum. Air is pumped through the tube to make the colon bigger and easier to see. After this is done, you’ll be asked to lie on your back. Next, the table slides into a large tunnel through the machine, where x-rays create images of your colon. You must stay very still during this procedure, since movement can blur the pictures. You may be asked to hold your breath briefly while each picture is taken. A computer combines all the images to form a three-dimensional picture of the colon, which are viewed on a video monitor. Pictures are also taken while you lie on your stomach. The exam takes about 20 minutes. How to prepare for the test:
Preparations can vary, depending on your health care provider. Everyone undergoing any type of colonoscopy must completely empty their bowels before the exam. This may be done using an enema or laxatives combined with a liquid diet the day before the test. The bowel must be completely emptied until no solid matter remains.
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