CT Colonography in Patients at Elevated Risk for Colorectal Cancer

Computed tomographic (CT) colonography to screen for colorectal cancer has been studied primarily in average-risk populations. In this European study, 937 people at higher risk (family history of colorectal cancer, personal history of adenomas, or positive fecal occult blood testing [FOBT]) were recruited to undergo CT colonography followed by colonoscopy on the same day in expert facilities. Endoscopists were initially blinded to the colonography results, which were disclosed if needed to reconcile discrepancies in findings.

The “gold standard” outcome was defined as an adenoma ≥6 mm with worrisome features on colonoscopy. Compared with colonoscopy, the positive predictive value of CT colonography was 62%, and the negative predictive value …