Cecal mobility: a potential pitfall of CT colonography.

OBJECTIVE: On CT colonography, feces is differentiated from a polyp primarily by texture and mobility. When feces is soft-tissue in density and polypoid in shape, only its mobility is the clue to the correct diagnosis. There are reports of false-negative examinations caused by the mobility of bowel mimicking lesion movement. We studied the mobility of the cecum as seen on CT colonography to determine how often this potential pitfall exists.
CONCLUSION: Rotation of the cecum is geometrically complex and occurs in several planes. It explains previous anecdotal reports of false-negative diagnoses. When solid feces is suspected in the cecum based on mobility, the reviewer should take the time to carefully analyze mobility of the cecum using multiplanar images.