A virtual colonoscopy, or a CT colonoscopy, is performed using computer tomography scanning to get an image of the interior of the colon, according to RadiologyInfo.org. This procedure is less invasive than an endoscopy in which an exploratory tube is inserted into the rectum and passed through the colon.
For a virtual colonoscopy, the patient is placed facing up in a CT scanning table with cushions for support and to remain in the proper position if necessary, explains RadiologyInfo.org. A small tube is inserted a couple of inches into the rectum to insert air or carbon monoxide into the colon area. This extends the wrinkles of the colon and allows for a clearer image to be constructed from the scan. The table and patient are then passed through the scanning machine, and the process is repeated with the patient facing down or on one side.
The patient is alone in the exam room during the actual scanning, reports RadiologyInfo.org. If necessary, a parent, wearing a lead shield to protect from the radiation, is allowed to remain in the room with a child patient. However, a radiologist remains in constant contact with the patient throughout the procedure through an intercom system.