Virtual Colonoscopy as Effective as Conventional Method

CHICAGO, Dec. 3 -- Three-dimensional computed tomography (CT) colonography, also known as virtual colonoscopy, is as sensitive as and less invasive than conventional colonoscopy in screening average-risk patients, according to research presented at the Radiological Society of North America's (RSNA) annual meeting this week. The new technology allows radiologists to obtain 3-D images from different angles, providing a "movie" of the interior of the colon without having to insert a scope.

"I believe virtual colonoscopy will eventually join conventional colonoscopy as a major component of colorectal cancer screening in the US," said lead author Perry J. Pickhardt, MD, an associate professor of radiology at University of Wisconsin Medical School in Madison. A clinical trial conducted at the National Naval Medical Centers in Bethesda, Md., the Naval Medical Center in San Diego and at Walter Reed Army Medical Center (Walter Reed) in Washington, DC.

Colon polyps are benign growths that may develop into colon cancer if not removed. Many people resist screening because of the discomfort caused by conventional colonoscopy and other tests.

"The goal of screening with virtual colonoscopy is to increase the number of patients that would participate," said co-author Lt. Col. J. Richard Choi, ScD., MD, principal investigator of the Virtual Colonoscopy Screening Project at Walter Reed. "Even though colorectal cancer is the second leading cause of cancer death and is almost always preventable, less than half of eligible patients undergo any form of screening."

In recent years, radiologists have begun using CT colonography to screen for colon polyps. Although it is less invasive, until now the procedure primarily used 2-D CT slices (images) for polyp detection, which are likely to be less sensitive, the RSNA said. With virtual colonoscopy, there is no risk of bleeding or of perforating the colon. There is no need for intravenous sedation, and the procedure is less costly than conventional colonoscopy. It also is more convenient, taking 15 minutes or less, because patients are not sedated.

"The findings of this study should establish virtual colonoscopy as a viable screening option," Dr. Pickhardt said. "This less invasive screening option will likely encourage more adults to seek testing, resulting in many additional lives saved."

As a result of this study, Walter Reed is now offering virtual colonoscopy as an alternative to conventional colonoscopy screening.

For more information, visit: www.rsna.org