CT is an abbreviation for computed tomography, which is a valuable diagnostic medical exam that combines X-rays and computers. CT Colonography is a noninvasive technique for evaluating the interior of the colon or large intestines. This technique uses a computer to give a more in-depth clinical evaluation with 3-D images. More traditional means of examining the colon would be a colonoscopy, which is where an endoscope is inserted into the rectum. CT Colonography is used to diagnose colorectal disease such as polyps, diverticulitis and cancer.
The day before the exam, the patient will be given a laxative or suppository to clear out the colon and rectum. A solution designed to coat any residual feces will be given right before the examination, to avoid viewing of any remaining feces that could cause be mistaken for a polyp and cause a false positive result.
The patient will be positioned appropriately on the CT scanner. A very small, flexible tube will be inserted approximately two inches into the rectum and air is gently pumped into the colon. This will help with creating clearer images by reducing wrinkles in the colon.
The table will them move into the scanner and multiple images of the colon will be taken. The patient will be asked to hold their breath for about 10-15 seconds to avoid distortion in the images. The procedure should take approximately 10-15 minutes and does not require any sedation or a scope. The images that are created produce a three dimensional image of the colon, which will be viewed by a radiologists like a conventional colonoscopy.
You may resume normal daily activity. The virtual or CT colonography is less invasive than traditional colonoscopy, so the only discomfort would be the full feeling from the air being inserted into the colon prior to imaging.
If any polyps are located, a traditional colonoscopy will have to be ordered to do a polypectomy or biopsy. If you have any further questions, please contact your physician.