1. From the Department of Radiology (M.S.P., A.R.G., M.A.E., L.R.S., R.W.W., A.K.N., R.M.S., A.M.F.), Department of Medical Physics (L.R.S., R.M.S., A.M.F.), and Department of Pathology and Laboratory Medicine (M.R.), University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI 53792-3252; and University of Wisconsin Carbone Cancer Center, Madison, Wis (A.K.N., R.M.S., A.M.F.).