What is CT Colonography (Virtual Colonoscopy)?
CT colonography uses X-ray pictures taken from multiple different angles around the body to create cross-sectional images that appear as “slices” of the organs in the abdomen and pelvis. When the colon is distended with gas, these images can be viewed on a special computer workstation that allows the inner walls of the colon to be evaluated in a manner similar to colonoscopy, which is a more invasive procedure.
CT colonography is a safe screening tool that can be used to detect colon polyps in individuals with a relatively low risk of colon cancer. CT colonography is much less invasive than colonoscopy; however, if a large (1 cm or larger) polyp is found, a regular colonoscopy examination may be recommended in order to allow the polyp to be removed. If a smaller (between 6-9 mm) polyp is found, a follow up CT colonography examination in 3 years may be recommended to follow up on the size of the smaller polyp, as these smaller polyps have a less than 1 percent chance of becoming cancerous. You should discuss the pros and cons of CT colonography with your gastroenterologist or other healthcare provider to determine which screening procedure is most appropriate for you. You should also be aware that CT colonography is still considered by some to be an investigational study and may not be covered by your insurance carrier.
You are not a candidate for CT colonography if:
• You have acute diverticulitis (the procedure should not be performed until you have had 4-6 weeks of treatment and your symptoms have resolved).
• You have active inflammatory bowel disease (ulcerative colitis or Crohn’s disease).
• You have a colostomy bag.