1. Radboud University Nijmegen Medical Center; Department of Surgery and Trauma; PO Box 9101 Nijmegen Netherlands 6500 HB
2. University of Groningen, University Medical Center Groningen; Department of Critical Care; Hanzeplein 1 Groningen Netherlands 9713 GZ
3. Canisius Wilhelmina Hospital; Department of Radiology; PO Box 9101 Nijmegen Netherlands 6500 HB
4. VU Medical Center; Department of Surgery; De Run 4600 Amsterdam Brabant Netherlands 5504