1. Department of Urology, Philipps-University Marburg, Marburg, Germany
2. Department of Radiology, Philipps-University Marburg, Marburg, Germany
3. Department of Urology, Philipps-University of Marburg, Baldingerstraße, DE-35043 Marburg/Lahn, Germany. Tel: +49 6421 28 62513. Fax: +49 6421 28 65590. E-mail: wille@post.med.uni-marburg.de