1. From the Department of Radiology (Y.Y., E.S., M.H.) and Department of Preventive Medicine and Public Health, Biostatistics Unit at Clinical and Translational Research Center (T.A.), Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan; Department of Radiology, Nippon Koukan Hospital, Kawasaki, Japan (Y.Y., K.O.); and Department of Radiology, St. Luke’s International Hospital, Tokyo, Japan (M.M., Y.S.).