1. From the Department of Radiology (N.S., Y.N., A.R.H., S.P., T.A.M.), Department of Surgery, Division of Urology (N.S., R.H.B., C.M.), and Department of Anatomical Pathology (T.A.F.), The University of Ottawa, The Ottawa Hospital, 1053 Carling Ave, Rm C1, Ottawa, ON, Canada K1Y 4E9; and the Department of Epidemiology, The Ottawa Hospital Research Institute, Ottawa, Canada (T.R.).