CT Colonography: Single- versus Multi–Detector Row Imaging

Abstract

PURPOSE: To compare respiratory artifacts, colonic distention, and polyp detection at computed tomographic (CT) colonography by using single– and multi–detector row helical CT systems. MATERIALS AND METHODS: A total of 237 consecutive patients received subcutaneously administered glucagon and underwent prone and supine CT colonography with single–detector row CT (n = 77) and multi–detector row CT (n = 160), followed by colonoscopy. Examination results were graded for colonic distention, respiratory artifacts, and polyp depiction by two radiologists working independently. RESULTS: Suboptimal colonic distention was significantly more common with single–detector row CT and was present in at least one segment in 52% (40 of 77 patients) of examinations versus only 19% (30 of 160 patients) with multi–detector row CT (P < .001). Mild respiratory artifacts were present in 61% (47 of 77 patients) of single–detector row CT examinations versus only 16% (26 of 160 patients) of multi–detector row CT examinations (P < .001). Depiction of polyps larger than 10 mm was 89% (eight of nine polyps) for single–detector row CT and 80% (eight of 10 polyps) for multi–detector row CT (P > .05). CONCLUSION: CT colonography performed with multi–detector row CT significantly improved the demonstration of colonic distention and depicted fewer respiratory artifacts compared with single–detector row CT. No significant differences in the depiction of polyps larger than 10 mm were demonstrated between single– and multi–detector row CT for a small number of polyps. Studies with a larger prevalence of clinically important polyps are needed for further evaluation of differences in polyp detection.