Diagnostic performance of computed tomography colonography in symptomatic patients and in patients with increased risk for colorectal disease.

PURPOSE

To evaluate the diagnostic performance (colorectal lesions) of computed tomography (CT) colonography in 111 patients, a majority of whom were at high risk for colorectal neoplasia.

MATERIAL AND METHODS

After bowel preparation, CT colonography was performed, immediately followed by conventional colonoscopy. The diagnostic performance of CT colonography was analyzed relative to lesion size, histological diagnosis, and diagnostic certainty.

RESULTS

The sensitivity of CT colonography increased with lesion size (P<0.001), and was 91% (21/23) for lesions > or = 10 mm. All 10 carcinomas and 86% (19/22) of adenomas > or = 5 mm were detected. Unconfirmed or false-positive CT findings were generally small and/or reported with low diagnostic certainty. The specificity of CT colonography would be 45% (30/66; 95% CI 34% to 57%) if patients with findings of any size and any diagnostic certainty were selected for follow-up, and 92% (85/92; 95% CI 85% to 96%) if only patients with CT findings > or = 10 mm classified as certain were selected.

CONCLUSION

CT colonography had a high sensitivity for lesions > or = 5 mm. The diagnostic performance increased with lesion size and degree of diagnostic certainty, and was higher for adenomas.