1. University Dusseldorf; Medical Faculty, Department of Diagnostic and Interventional Radiology; Dusseldorf Germany
2. University Dusseldorf; Medical Faculty, Department of Nephrology; Dusseldorf Germany
3. Department of Diagnostic and Interventional Radiology; University Hospital Tuebingen; Tuebingen Germany
4. University of Dusseldorf; Medical Faculty, Department of Urology; Dusseldorf Germany