1. From the Mallinckrodt Institute of Radiology (A.S.S., T.J.F., D.H.B., M.J.H., M.I., M.Z.R., M.H.L., B.M.C., A.L.M., J.A.C.L., J.C., C.R.C., R.S.H., M.M., J.G.U., C.L.S., D.R.L.) and Division of Urologic Surgery (E.H.K.), Washington University School of Medicine, 510 S Kingshighway Blvd, Campus Box 8131, St Louis, MO 63110.