1. From the Departments of Radiology (N.E.E., H.Y., N.N., Y.I.), Emergency and Critical Care Medicine (S.I.), Pathology (M.M.), and Surgery (S.S.), Tokai University School of Medicine, Shimokasuya 143, Isehara, Kanagawa 259-1193, Japan; and Department of Radiology, Tsuchiura Kyodo General Hospital, Tsuchiura, Ibaraki, Japan (S.K.).