1. Department of Medical Imaging, Royal Inland Hospital, 311 Columbia St, Kamloops, BC V2C 2T1, Canada.
2. Department of Radiology, Division of Emergency Radiology, Harvard Medical School, Brigham and Women's Hospital, Boston, MA.
3. Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Harvard Medical School, Brigham and Women's Hospital, Boston, MA.