Figure 6b. False-positive CT colonographic findings in 55-year-old man. (a) Coronal CT colonographic image shows a smooth round 6-mm mass (arrow) without an internal area of hyperlucency on the fold in the ascending colon. (b) Three-dimensional volume-rendered CT image of the mass seen in a shows a polypoid morphologic structure consistent with a polyp (arrow). At colonoscopy, no lesion was seen. Although we considered this lesion to be a false-positive finding, it is possible that it was a true polyp that was missed at colonoscopy.