1. From the Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto 860-8556, Japan (Y.N., T.I., S.O., S.T., T.N., O.I., T.H.); and Department of Clinical Investigation, Kumamoto University Hospital, Kumamoto, Japan (J.M.).