1. From the Department of Radiology and Biomedical Imaging (A.S.G., B.J.S., G.B.J., N.C., J.B.G., J.M.W., L.F., T.M.L.) and Department of Epidemiology and Biostatistics (M.C.N., C.E.M.), University of California San Francisco, 185 Berry St, Suite 350, San Francisco, CA 94107. From the 2015 RSNA Annual Meeting.