1. From the Departments of Radiology (K.Y., H.N., H.I., O.K., S.Y., T.K., O.T., T.N.) and Neurology (K.S., K.T., M.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan, and Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Md (S.M.).