[1] Univ Freiburg, Dept Radiol, Med Ctr, Fac Med, Hugstetter Str 55, D-79106 Freiburg, Germany
[2] Johannes Gutenberg Univ Mainz, Univ Med Ctr, Dept Diagnost & Intervent Radiol, Langenbeckstr 1, D-55131 Mainz, Germany
[3] Univ Freiburg, Fac Med, Med Ctr, Dept Urol, Hugstetter Str 55, D-79106 Freiburg, Germany