1. From the Departments of Radiology (S.P., M.A.G., V.G.) and Urology (L.E.P.), University Hospitals Case Medical Center, 11100 Euclid Ave, Bolwell B120, Cleveland, OH 44106-0500; Department of Epidemiology and Biostatistics (N.K.S.) and Department of Biomedical Engineering (M.A.G., V.G.), Case Western Reserve University, Cleveland, Ohio; and Case Western Reserve University School of Medicine, Cleveland, Ohio (Z.L.).