Comparison of virtual colonoscopy with conventional colonoscopy in detection of colorectal polyps

To determine the sensitivity and specificity of multidetector computed tomography-based virtual colonoscopy for colorectal polyp detection by using conventional colonoscopy as the reference standard.

48 patients with high risk for colorectal cancer underwent virtual colonoscopy followed by conventional colonoscopy. Examination results were compared with conventional colonoscopy, which served as the gold standard.

Virtual colonoscopy correctly depicted 19 of 22 polyps (sensitivity, 86%) that were detected in conventional colonoscopy. All 4 polyps that were greater than 10 mm in size (100%), 6 of 7 polyps 6-9 mm in size (85%), and 9 of 11 polyps 5 mm in size or smaller (81%) were correctly depicted with virtual colonoscopy. Virtual colonoscopy had an overall sensitivity of 86% and specificity of 98%.

Multidetector computed tomography-based virtual colonoscopy has excellent sensitivity for the detection of clinically important colorectal polyps.