1. From the Department of Radiology (Y.S.H., C.J.L., H.M.W., W.Y.G., C.B.L., C.C.W.) and Neurologic Institute, Department of Neurosurgery (W.Y.C., K.D.L., H.C.Y., C.C.L.), Taipei Veterans General Hospital, 201 Shipai Rd, Sec 2, Beitou District, Taipei 112, Taiwan (ROC); and School of Medicine, National Yang Ming University, Taipei, Taiwan (ROC) (Y.S.H., C.J.L., H.M.W., W.Y.G., C.B.L., C.C.W., W.Y.C., K.D.L., H.C.Y., C.C.L.).