1. Department of Surgery, University Hospitals of Geneva and Medical School
2. Emergency Radiology Unit, Service of Radiology
3. Department of Surgery, Montreal University Hospital CHUM, Université de Montréal, Montréal, Quebec, Canada
4. Division of Clinical Epidemiology, Faculty of Medicine, University of Geneva and Geneva University Hospitals, Geneva, Switzerland
5. Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA