Virtual Colonoscopy Exams? Yes, They Are Effective
Published November 2007
New evidence supports a “virtual” option for the 40 million Americans who avoid potentially life-saving colorectal cancer screening exams because of anxiety over the invasive nature of colonoscopies.
A study recently published in the New England Journal of Medicine (NEJM) reported that “virtual colonoscopies”—performed using computed tomography (CT) technology—are as effective for detecting polyps (growths) and early-stage colorectal cancers as the traditional colonoscopy exam.
UC radiologists have performed virtual colonoscopy screening exams for the past four years in patients who cannot tolerate sedation and now offer the option to the general public. The procedure is less invasive and requires far less time than traditional exams.
“Major medical studies have proven that virtual colonoscopies are just as accurate as traditional colonoscopies for diagnosing colorectal cancer,” says Howard Feigelson, MD, a UC volunteer assistant professor of radiology and body imaging specialist at University Hospital.
“We hope that more people will get this life-saving screening test now that a scientifically proven, less-invasive option is available.”
Prior to both traditional and virtual colonoscopy exams, patients are required to follow a liquid-only diet for 24 to 48 hours and take laxatives to cleanse the colon and rectum. The colon is then inflated with carbon dioxide as a contrast material to improve the visual field.
During a traditional colon-oscopy, the patient is sedated and the physician uses a fiber optic scope equipped with a camera to inspect the entire colon for potentially cancerous growths.
In contrast, the virtual exam requires no sedation and uses a series of rapidly acquired CT scans to diagnose any problems. The virtual procedure takes about 20 minutes and the patient can immediately resume normal activities. The traditional procedure takes about an hour.
UC gastroenterologists caution, however, that virtual colonoscopies do not allow physicians to immediately address any growths they find.
“Using traditional screening colonoscopies, we’re able to remove any polyps immediately,” says Jonathan Kushner, MD, a gastroenterologist and associate professor of medicine. “This can save the patient the time and emotional stress of booking a second procedure to explore any problem areas identified during a virtual exam.”
According to the NEJM study, 8.3 percent of patients who had a virtual colonoscopy had to return for a traditional procedure.
Although opinions vary on the merits of virtual versus traditional colonoscopy, the entire UC Physicians team agrees on the bottom line: If virtual colonoscopies entice more people to get timely colorectal cancer screenings, it’s a good thing.
“With proper screening and surveillance, the vast majority of colorectal cancer can be found early enough to be cured,” says Janice Rafferty, MD, chief of colon and rectal surgery at UC.
The American Cancer Society recommends that all adults get an initial colorectal screening exam at age 50, with periodic surveillance exams to follow.
UC Health Line features timely health information and tips for consumers. Read new Health Lines every Thursday or access archives at healthnews.uc.edu.
Howard Feigelson, MD, and Lisa Renner, review CT scans of a colon in the 3D post-processing lab at University Hospital.