1. From the Department of Radiology (M.E., E.S.B.), Department of Biostatistics and Medical Informatics (G.L.), and Carbone Comprehensive Cancer Center (E.S.B.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792; American College of Radiology, Reston, Va (M.B.); and Department of Radiology, Stanford University School of Medicine, Stanford, Calif (W.B.D.).