Abstract
The diagnostic accuracy of CT colonography (CTC) by 64-row multislice CT was evaluated. The detection rate was evaluated according to the size and gross morphology of the lesion in 275 lesions (≥2 mm) in 208 patients who underwent total colonoscopy and CTC on the same day. The sensitivity was 36.9% at a tumor size of 2 mm, 52.5% at 3 mm, 79.6% at 4 mm, 72.2% at 5 mm, and 100.0% at ≥6 mm. The positive predictive value was 76.5% for lesions 6 mm or larger. In elevated lesions, the sensitivity was 60.0% for Is (sessile), 100% for Isp (subpediculate) and 100% for Ip (pediculate), with a mean of 64.3%. In superficial lesions, the sensitivity was low, at 40% (4/10), for IIa (including LST). Colon cancer could be detected by CTC in all 4 patients. Since the detection rate of lesions 6 mm or greater, which are treatment targets, by CTC was satisfactory, CTC may become a useful modality for colon cancer screening.
