1. From the Department of Radiology and Research Institute of Radiology (J.H.S., S.H.C., S.Y.K., J.H.B., H.J.W., S.J.L.), and Department of Gastroenterology (Y.S.L.), University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea; Department of Radiology, National Cancer Center, Goyang, South Korea (H.Y.J.).