Diagnostic performance of CT colonography with limited cathartic preparation in colorectal cancer screening; comparison with conventional colonoscopy

Abstract

PurposeTo prospectively evaluate the diagnostic performance of computed tomographic colonography with limited bowel preparation for the depiction of colorectal polyps, by using conventional colonoscopy as the gold standard technique. Material and MethodsThe study included forty five consecutively registered patients referred for conventional colonoscopy for colorectal cancer screening or for evaluation of colorectal symptoms, and they were scheduled to undergo MDCT examination on the same day at Radiology Department in our institution, before the conventional colonoscopy examination. All patients undergo limited preparation main outcome measures: sensitivity, specificity, positive and negative predictive value of CTC versus CC in each group and overall. ResultsA total of 60 polypoid lesions were detected with colonoscopy in 45 patients; overall sensitivity of CTC in polyp detection was 85.71%, specificity 71.24, PPV 96.77 and NPV 33.33, as regarding CTC performance in each group. ConclusionThis study proved that CTC with limited cathartic bowel preparation and iodinated agents for fecal tagging can obtain high sensitivity and PPV values results for <5mm polyps comparable to those obtained with conventional preparation with laxatives. Furthermore, this method could really improve the acceptance of CTC for colorectal cancer screening.