1. From the Department of Radiology (B.R.K., J.M.L., D.H.L., J.H.Y., J.K.H.), Institute of Radiation Medicine (J.M.L., J.K.H.), Department of General Surgery (K.S.S., N.J.Y.), and Department of Pathology (K.B.L.), Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea; and Department of Radiology, National Cancer Center, Seoul, Korea (B.Y.H.).