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Health Capsules
November 2008
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“Virtual” Colon Scans Show Promise

A colonoscopy can identify colon cancer at an early stage, when it’s easiest to treat. But some people hesitate to undergo this invasive procedure, which uses a long, flexible tube with a camera to view the lining of the colon. Now scientists report that a newer technique called virtual colonoscopy can detect most of the large colon polyps that can be found by standard colonoscopy.

Virtual colonoscopy takes a series of x-ray scans of the lower belly. A computer then puts the pictures together to create 3-D images and videos of the inside of the colon.

To compare the accuracy of the new and old techniques, NIH-funded researchers examined more than 2,500 patients, age 50 or older. Each had a virtual colonoscopy followed by a standard one.

Virtual colonoscopy successfully identified about 90% of the patients who had larger polyps, measuring about a ¼ inch or more, that were identified by standard colonoscopy. However, the virtual scan was less effective at detecting smaller polyps.

Both techniques have advantages and drawbacks. Virtual colonoscopy isn’t as accurate as the standard one, but it may be more appealing for those put off by the long tube and sedation used in regular colonoscopy.

A key benefit of standard colonoscopy is that physicians can remove suspicious polyps immediately during the procedure. The long tube—or scope—includes tools for tissue removal. In contrast, patients undergoing a virtual scan must schedule a followup regular colonoscopy to have suspicious polyps removed.

“The most important advice we can give to patients is to get screened,” said study coauthor Dr. Paul Limburg of the Mayo Clinic in Rochester, Minnesota. “How they get screened should be an individual decision based upon discussions between patients and their providers.”

Definitions iconDefinitions

Fleshy growths that stick out from the inside lining of the colon. Over time, they may develop into cancer.

Links iconWeb Sites

Colon and Rectal Cancer

Colorectal Cancer Screening

Questions and Answers: Results of the National CT Colonography Trial

Virtual Colonoscopy

Virtual Colonoscopy Video

  Information on Drug Abuse and Addiction

Why do some people become addicted to drugs while others don’t? How do drugs work in the brain? Where can you turn to learn more about drug abuse and addiction?

You can find the answers at DrugPubs, a new information center that distributes a wide range of free or low-cost materials on a variety of drug abuse topics, from Marijuana: Facts for Teens to Preventing Drug Use Among Children and Adolescents.

Many of the materials—including fact sheets, brochures, pamphlets and videotapes—are available in both English and Spanish. DrugPubs is a service of NIH’s National Institute on Drug Abuse (NIDA).

To see a list of available materials, visit Most are available for online viewing or downloading. To order them, call 1-877-NIDA-NIH (1-877-643-2644) or 1-240-645-0228 (TDD), or e-mail Online ordering will be available soon.



Links iconFeatured Web Site

Children & Clinical Studies

Treatments for children are often based on what works in adults. But children aren’t little adults. Kids who participate in clinical studies can help save lives and improve the health of countless children. This new web site, with videos from kids, parents and experts, offers an insider’s guide to help parents make well-informed decisions about whether to enroll their child in a clinical study.

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