1. Department of Radiology, University Hospital Regensburg , Regensburg Germany
2. Department of Surgery, Robert-Bosch-Hospital , Stuttgart , Germany
3. Department of Radiology, Hospital Braunschweig , Braunschweig Germany
4. Department of Surgery, University Hospital Regensburg , Regensburg , Germany
5. Center for Clinical Trials, University Hospital Regensburg , Regensburg , Germany