1. From the Departments of Clinical Radiology (O.T., A.H., K. Yamashita, K.K., R.K., H.H.) and Neurosurgery (A.N., K.A., K. Yoshimoto, K.I.), Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan; and Philips Electronics Japan Healthcare, Tokyo, Japan (M.O., M.V.C.).