Virtual colonoscopy was found to be highly accurate for detection of intermediate (6-9 millimeters) and large (greater than 1 centimeter) polyps. Because the majority of patients will not have a polyp, no further workup is necessary. Only the 12 percent of patients identified with a polyp during a colonography would then need to have a colonoscopy. Because most colon cancer arises from preexisting polyps, detection and removal of these lesions can help eradicate it.
Dr. Johnson said that how people get screened should be an individual decision, based on discussions with their medical providers. Virtual colonoscopies may be considered for patients who:
• Have had a difficult time with previous colonoscopy procedures
• Are on anti-coagulant drugs
• Have a colon obstruction
• Prefer not to have a standard colonoscopy.
Despite the known benefits of colorectal screening, studies show that the majority of Americans 50 and older do not have it done. Colorectal cancer is the third most frequently diagnosed cancer and the second-leading cause of U.S. cancer deaths.
Mayo Clinic has been using and studying virtual colonoscopy since the technique began in the 1990s. Mayo published the first report in the scientific literature on the clinical effectiveness of virtual colonoscopy and was the first to offer it for routine care; Mayo has since performed thousands of virtual colonoscopies, and continues to study ways to improve the procedure.