1. From the Departments of Diagnostic Radiology (S.O., T.N., M.K., D.U., Y.N., Y.Y.), Medical Physics (Y.F.), Cardiology (S.T., K.T.), and Neurology (M.U., T.Y., Y.A.), Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto 860-8556, Japan; and Department of Central Radiology, Kumamoto University Hospital, Kumamoto, Japan (T.E.).