1. From the Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792 (M.H.L., M.G.L., T.A.K., A.R., A.G., P.J.P.); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Mo (V.M., S.B.); and Department of Pathology, University of Wisconsin School of Medicine and Public Health, Madison, Wisc (D.B.).