Virtual Colonoscopy

The American Cancer Society's 2008 guidelines endorsed virtual colonoscopy as an appropriate screening modality for colorectal cancer (CRC).

Quick view of the benefits: Non-invasive, less time (about 20 minutes table time/ actual scanning takes about 2 minutes), and no sedation so return to normal life quickly.

This is an easier screening test to endure which makes a screening test more acceptable and more compliant with ACS recommendation for when you should have a colorectal screening. More persons will have it completed because of the less invasive character of the exam.

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What are the benefits?

  • This new minimally invasive test provides both 2-D and 3-D images that can depict many polyps and other lesions as clearly as when they are directly seen by conventional colonoscopy.
  • CT colonography has a markedly lower risk of perforating the colon than conventional colonoscopy. Most people who undergo CT colonography do not have polyps, and can be spared having to undergo a full colonoscopy.
  • CT colonography is an excellent alternative for patients who have clinical factors that increase the risk of complications from colonoscopy, such as treatment with a blood thinner or a severe breathing problem.
  • Elderly patients, especially those who are frail or ill, will tolerate CT colonography better than conventional colonoscopy.
  • CT colonography can be helpful when colonoscopy cannot be completed because the bowel is narrowed or obstructed for any reason, such as by a large tumor.
  • If conventional colonoscopy cannot reach the full length of the colon—which occurs up to 10 percent of the time—CT colonography can be performed on the same day because the colon has already been cleansed.
  • CT colonography provides clearer and more detailed images than a conventional barium enema x-ray examination.
  • CT colonography can detect abnormalities outside of the colon, including early-stage malignancies and potentially dangerous conditions, such as abdominal aortic aneurysms.
  • CT colonography is tolerated well. Sedation and pain relievers are not needed, so there is no recovery period.
  • CT colonography is less costly than colonoscopy.

How should I prepare?

You should wear comfortable, loose-fitting clothing to your exam. You will be given a gown to wear during the procedure.

Women should always inform their physician and the CT technologist if there is any possibility that they may be pregnant. See the Safety page for more information about pregnancy and x-rays.

The bowel-cleansing regimen for CT colonography is similar to that for a colonoscopy. Your diet will be restricted to clear liquids the day before the examination. It is very important to clean out your colon the night before your CT colonography examination so that the radiologist can clearly see any polyps that might be present. You will be asked to take either a set of pills or a liquid laxative. Some common preparations are NuLytely®, Go-Lytely® (Polyethylene glycol electrolyte solutions) or Magnesium Citrate or bisacodyl tablets. Additional agents may also be taken the day before the exam. These may include small quantities of barium and iodinated liquids. These agents help the radiologist better distinguish stool from polyps by "tagging" the remaining stool and fluid.

Be sure to inform your physician if you have heart, liver or kidney disease to be certain that the bowel prep will be safe. Your physician can advise you on dietary restrictions prior to the exam. You will be able to resume your usual diet immediately after the exam.

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