[A case of giant peritoneal loose body: usefulness of wide window width CT]

We encountered a case of giant peritoneal loose body, which was detected on barium enema by chance. Unenhanced CT showed a round mass with calcified center. On MR examination, the mass moved to the pelvic cavity from the position at CT examination. T1- and T2-weighted images showed a mass with low signal intensity. The contrast-enhanced T1-weighted images showed no enhancement. From these findings, peritoneal loose body, in addition to teratoma, granuloma, and foreign body, was suspected. However, the wide window width CT clearly showed a concentric calcification, a finding that is characteristic of peritoneal loose body.