1. From the Departments of Radiology (A.D.L., M.A.M.) and Surgery (W.B.A.), Medstar Georgetown University Hospital, 3800 Reservoir Rd NW, Washington, DC 20007; the American Institute for Radiologic Pathology, Silver Spring, Md (M.A.M.); and the Center for Cancer Research, National Cancer Institute, Bethesda, Md (M.M.M.).