COLORECTAL POLYP DETECTION WITH CT COLOGRAPHY - 2-DIMENSIONAL VERSUS 3-DIMENSIONAL TECHNIQUES - WORK-IN-PROGRESS

PURPOSE: To compare detection of colorectal polyps with two-dimensiona l (2D) computed tomographic (CT) colography only, three-dimensional (3 D) CT colography only, and a combination of 2D and 3D CT colography. M ATERIALS AND METHODS: A total of 11 computer-simulated polyps (1-10 mm ) were placed randomly in five identical CT data sets for images of a 72-year-old man's polyp-free, rectosigmoid colon. Fifteen CT colograph ic data sets were produced: five with 2D CT images only, five with 3D CT images only, and five with 2D and 3D CT images. Two radiologists ra ndomly, blindly, and independently evaluated all 15 data sets to detec t the simulated polyps. RESULTS: No polyps 2 mm or smaller were detect ed. No statistically significant differences in the detection of color ectal polyps were found between the three techniques. However, the com bination of 2D and 3D CT colography resulted in polyp detection rates that were greater than or equal to those of 2D or 3D CT colography alo ne. Flat polyps were more difficult to detect than sessile polyps. Fiv e false-positive findings occurred with 2D CT colography. CONCLUSION: A combined display of 2D and 3D CT images likely provides the greatest rate of detection of colorectal polyps.