1. From the Departments of Medical Physics (M.G.W., Y.L., T.P.S., C.A.M.), Radiology (J.L.H., T.P.S., P.L., C.A.M., F.T.L.), Urology (J.L.H., F.T.L.), and Biomedical Engineering (T.P.S., F.T.L.), University of Wisconsin–Madison, 1111 Highland Ave, Madison, WI 53705.