1. From the Department of Radiology and Imaging Sciences, Clinical Center (A.S., M.B., F.F., N.M.B., L.R.F., E.C.J., R.M.S.), and National Cancer Institute, Medical Oncology Branch and Affiliates (A.B.A.), National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892.