Virtual Colonoscopy

Virtual colonoscopies can be performed by the GI Division of Premier Medical Group.

What is a virtual colonoscopy?

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Virtual colonoscopy is a procedure used to look for signs of pre-cancerous growths (called polyps), cancer, and other diseases of the large intestine. Images of the large intestine are taken using computerized tomography (CT) scan. Sometimes, magnetic resonance imaging (MRI) may be used for this test. A radiologist views the images on a computer, which puts together an animated, three-dimensional view of the inside of the large intestine. These views are similar to views obtained by optical colonoscopy. These images can be manipulated to afford the radiologist a detailed view of the inside of the colon and rectum.

With a virtual colonoscopy, a small rubber catheter is inserted into the rectum; the colon is expanded by introducing puffs of air through this catheter. Usually the patient lies on his or her back while hundreds of images are collected. The entire procedure takes about 15 minutes, and the patient can return to normal activities immediately. Typically there are no side effects.

With a virtual colonoscopy, the doctor is able to not only identify polyps, but other organs within the abdominal and pelvic regions. Other serious conditions can be seen; with optical colonoscopy, the doctor is limited to the inside of the colon.

A virtual colonoscopy is considered negative if the doctor does not see any abnormalities. It is considered positive if the images disclose any polyps or other abnormal tissue in the colon. If the test is positive, your doctor may recommend a traditional or optical colonoscopy so samples of the abnormal tissue can be taken for biopsy or so the polyps can be removed and also analyzed.

Do you need to prep for a virtual colonoscopy?

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With a virtual colonoscopy, the patient still needs to follow a special diet a day or two prior to the exam and take a laxative to cleanse the colon. The prep is similar to the prep used for optical colonoscopy.

Facts about virtual colonoscopy

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  • It does not require sedation
  • It is less invasive and faster to perform, with essentially no risk of perforation of the bowel wall
  • It provides images of major organs in addition to the entire colon
  • It can be performed in about 15 minutes, and the patient is able to resume normal activities immediately after the procedure
  • It involves injecting air into the colon which may be uncomfortable for some patients
  • Virtual colonoscopy is not as reliable as traditional colonoscopy in detecting small polyps
  • Virtual colonoscopy is not as precise as colonoscopy in finding flat cancers or polyps that are not protruding, or polyp-like
  • With a virtual colonoscopy, the doctor is not able to remove polyps. The patient would need to have the optical colonoscopy to remove the polyps, repeating the special diet and prep again
  • The radiation exposure with virtual colonoscopy is considered safe
  • It is more comfortable and produces less anxiety for patients
  • It is still considered experimental and not covered by most insurers