Virtual Colonoscopy
A virtual colonoscopy is a minimally invasive procedure used to examine the colon for any signs of abnormal growths, such as polyps or tumors that may indicate disease in the large intestine. This procedure uses computerized tomography (CT) imaging to provide the doctor with a three-dimensional view of the colon.
Reasons for a Colonoscopy
A colonoscopy is typically performed as a screening exam for abnormal growths in the large intestine that are or may become cancerous. A colonoscopy is recommended every 7 to 10 years for patients over 50 years of age, since the risk of colon cancer increases with age.
Patients at a higher risk for colon cancer should be screened every 5 years beginning at age 40. This latter category includes individuals with a family history of polyps, colorectal cancer or other hereditary gastrointestinal disease, and patients who have blood in the stool, unexplained abdominal pain, anemia or weight loss, or who suffer from any type of inflammatory bowel disease.
Benefits of a Virtual Colonoscopy
A virtual colonoscopy is less invasive than a traditional colonoscopy since it does not require inserting a tube all the way into the colon. The tube for the virtual procedure is inserted only about two inches into the rectum in order to inflate the area with gas. A traditional colonoscopy may not be able to examine narrowed or constricted intestines, but a virtual colonoscopy enables such exploration by inflating and expanding the area.
A virtual colonoscopy produces images that are just as clear as a traditional colonoscopy but through a shorter, more easily administered exam. Advantages of a virtual colonoscopy over a traditional procedure include:
- Three-dimensional view of the area
- No required sedation
- Virtually no risk of bowel perforation
Unfortunately, the same colonic cleansing is required in preparation for a virtual colonoscopy as for a traditional procedure.
The Virtual Colonoscopy Procedure
During a virtual colonoscopy, the doctor will insert a thin tube through the anus and into the rectum. Carbon dioxide is then pumped into the tube to expand the intestine for better viewing. The exam table is then moved through the CT scanner to capture three-dimensional, cross-sectional images of the large intestine that are later evaluated by the doctor. Patients are then asked to turn over and go through the scanner again for a second set of images.
The Risks of a Virtual Colonoscopy
While a virtual colonoscopy is generally safer than a traditional one, there is some risk involved in the use of the CT scanner which exposes the patient to more radiation than are emitted by ordinary X-rays.