1. From the Department of Diagnostic Radiology, Graduate School of Medical Sciences (Y.N., S.O., T.N., M.K., H.U., T.H.), and Department of Medical Radiation Sciences, Faculty of Life Sciences (Y.F.), Kumamoto University, 1-1-1 Honjo, Chuo-ku, Kumamoto 860-8556, Japan; and Department of Central Radiology, Kumamoto University Hospital, Chuo-ku, Kumamoto, Japan (D.S., M.G., T.E.).