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Virtual colonoscopy, or CT colonography, is a noninvasive, outpatient procedure that uses a CT scan to diagnose colon and bowel disease, including polyps, diverticulitis and cancer in the large intestine. Polyps are noncancerous growths on the intestine lining that may become cancerous.

Virtual colonoscopy is a good option for those at lower risk for colon cancer. It’s also an option for those whose conventional colonoscopy was incomplete or who can’t have one. Reasons for an incomplete colonoscopy include colon blockage from scarring or an abnormally shaped colon.

Some people also can’t have a conventional colonoscopy due to sedation risk from age, a health condition like COPD, or they can’t stop taking blood thinning medication.

What to Expect During Virtual Colonoscopy

At University of Maryland Medical Center, a radiologist and CT technologist perform the virtual colonoscopy. Your referring physician will give you preparation instructions including what foods to avoid for a few days beforehand. Although the preparation is similar to a conventional colonoscopy, virtual colonoscopy does not require sedation or use of a colonoscope, a fiber-optic tube with a camera.

You will lie on a table connected to the CT scanner. We expand your colon with carbon dioxide to improve visibility. During scanning, you will be in several different positions and need to hold your breath for a few seconds.

Like any other CT procedure, you will be awake while the virtual colonoscopy makes the highly detailed images that doctors use to make a diagnosis. The procedure usually takes less than 30 minutes. After the exam you can usually return to regular activities the same day.

One disadvantage of virtual colonoscopy is that any polyps found require conventional colonoscopy to remove them. There is no way to remove polyps or other abnormalities found during a noninvasive virtual colonoscopy.

Alternatives to virtual colonoscopy are barium enema and conventional colonoscopy.

Who Needs Virtual Colonoscopy

Women and men age 45 and older should have regular colon cancer screening. This includes virtual colonoscopy as an option every 5 years. People with increased risk of colon cancer, like those with a family history of it, should begin screenings at 40 or younger, at shorter intervals. Your doctor can help you determine when to begin screenings.

Risk factors for colon cancer include a persistent change in bowel habits, the presence of blood in the stool, abdominal discomfort or pain, bloating and unexplained weight loss.

Virtual Colonoscopy Risks

Air inflation has a slight risk of injuring your colon. You may also receive excess radiation exposure, although we follow all recommended radiation safety precautions.

Virtual Colonoscopy Benefits

  • Provides highly detailed 2D and 3D images of polyps and other lesions
  • Less risk of colon tearing than with conventional colonoscopy
  • No sedation or pain relievers needed
  • You can have a virtual colonoscopy the same day if conventional colonoscopy can’t be completed

Schedule an Appointment

To make a virtual colonoscopy appointment at the University Imaging Center, call 410-328-3225.