1. From the Departments of Radiology (T.F., C.S., B.P., D.C.M., D.V., C.N.), Nephrology (I.R.), and Urology (M.M.), Hospital Clínic de Barcelona, Villarroel 170, E3P1, 08036 Barcelona, Spain; Department of Radiology, Hospital Virgen de la Salud, Toledo, Spain (C.G.R.); and Department of Radiology, Fundación del Hospital Nacional de Parapléjicos, Toledo, Spain (F.G.).