1. From the Departments of Radiology (R.A.K., G.K.N., E.P.C., J.H.S., J.L.J., M.N., E.V.M.) and Pathology (A.A.), MedStar Georgetown University Hospital, 3800 Reservoir Rd NW, Washington, DC 20007; and Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY (V.L.M.).