1. From the Department of Radiology and Research Institute of Radiology (J.C., S.M.L.[1], K.H.D., S.M.L.[2], J.B.S.) and Department of Convergence Medicine (G.L., J.G.L.), University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro 43 Gil, Songpa-gu, Seoul 138-736, Korea.