1. From the Departments of Radiology (J.I., M.R., M.S., J.R.O., S.N., E.L., N.A.K.), Neurologic Surgery (S.C.P., R.R., T.H.S.), and Radiation Oncology (J.P.S.K.), NewYork-Presbyterian/Weill Cornell Medical Center, 515 E 71st St, S-120, New York, NY 10021; Weill Cornell Medical College, New York, NY (S.K., S.G.); and Department of Biomedical Engineering, Cornell University, Ithaca, NY (S.C.P.);