1. From the Department of Radiology, Research Institute of Radiology, Chung-Ang University Hospital, Seoul, Korea (S.M.H.); and Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43 gil, Songpa-gu, Seoul 05505, Korea (E.Y.C., J.H.C., H.H.K., H.J.S., W.J.C.).