Computed tomographic colonography (virtual colonoscopy): Blinded prospective comparison with conventional colonoscopy for the detection of colorectal neoplasia

Background and Study Aims: Computed tomographic colonography (CTC), also known as virtual colonoscopy, is a recently introduced imaging modality for the detection of colorectal neoplasia. The aim of our study was to evaluate the performance of CTC in a blinded comparison with conventional colonoscopy. Patients and Methods: A total of 66 consecutive, symptomatic patients underwent spiral computed tomography (CT) examination after standard bowel preparation. CT images were analyzed and subsequently compared with conventional colonoscopy findings. Results: Conventional colonoscopy detected 15 colorectal carcinomas and 52 polyps. CTC correctly identified all carcinomas, 13 of 14 polyps greater than 10.0 mm (sensitivity 92.8%; 95% confidence interval (95% CI); 77-100), 11 of 13 polyps between 6.0 and 9.0 mm (sensitivity 84.6%; 95% Cl; 62-100), and six of 25 polyps smaller than 5.0 mm (sensitivity 24%; 95% Cl; 6-42). The per-patient sensitivity and specificity were 93.7% and 94.1%, respectively. Conclusions: Computed tomographic colonography is an accurate imaging modality for the detection of colorectal neoplasia, especially for lesions larger than 6.0 mm in diameter.