1. From the Department of Radiology and Research Institute of Radiology (K.Y.K., J.H.P., J.T., M.T.K., S.G.K., H.Y.S.), Biomedical Engineering Research Center (J.H.P.), Department of Gastroenterology (Do Hoon Kim), and Department of Pathology (W.C.S.), Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Republic of Korea; and Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Ill (J.H.P., Dong-Hyun Kim).