1. Department of Radiology, University Hospital Rigshospitalet, Copenhagen, Denmark
2. Department of Radiology, Hvidovre Hospital, Copenhagen, Denmark
3. Department of Orthopedic Surgery, University Hospital Rigshospitalet, Copenhagen, Denmark
4. Department of Diagnostic and Therapeutic Neuroradiology, Hôpital Foch, Suresnes, France
5. Department of Radiology, Baylor College of Medicine, Houston, TX, USA