1. From the Department of Radiology, University of Missouri, One Hospital Dr, Columbia, MO 65212 (C.L.S., A.S.); Department of Surgery, University of California–San Francisco, San Francisco, Calif (E.L.); Department of Radiology, University of Southern California, Los Angeles, Calif (L.F.); and Department of Public Health Sciences, University of Virginia, Charlottesville, Va (J.T.P.).