1. From the Department of Radiology, Research Institute of Radiological Science (S.B., Y.S.C., S.S.A., S.K.L.), Department of Neurosurgery (J.H.C., S.G.K., E.H.K.), and Department of Pathology (S.H.K.), Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea; and Department of Radiology, National Health Insurance Service Ilsan Hospital, Goyang, Korea (S.B.).