Ileocecal valve imaging on computed tomographic colonography.

BACKGROUND: The aim of our study was to describe the visualization, normal anatomy, and variations of the ileocecal valve with computed tomographic (CT) colonography to provide information about its optimal imaging. METHODS: We analyzed data in two- and three-dimensional rendering mode in 71 consecutive patients who underwent routine CT colonoscopy followed by conventional colonoscopy for confirmation of the radiologic findings. RESULTS: Complete visualization of the ileocecal valve was better achieved in the supine than in the prone position (82% vs. 62%, respectively); the ileocecal valve appeared in 64% of cases in the supine position when it was invisible in prone position (p < 0.0001). Partial visualization of the ileocecal valve was possible in 94% of cases. The ileocecal valve was of labial type in 76%, papillary type in 21%, and lipomatous in 3% of cases. The orifice was identified in 53% of ileocecal valves; in two cases of cecal carcinoma, the normal ileocecal valve morphology was grossly disrupted. CONCLUSION: The ileocecal valve was at least partly visualized by CT colonoscopy in 94% of cases, more frequently in the supine position. Its most common normal morphology is the labial type. The absence of orifice visualization alone is not a specific sign for neoplasia, but its presence helps distinguish physiologic bulging from neoplasia.