1. Department of Diagnostic Radiology, Dalhousie University, Halifax, Nova Scotia, Canada
2. Department of Radiology, The Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada
3. Department of Epidemiology, The Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada
4. The Canadian Association of Radiologists, Ottawa, Ontario, Canada
5. Department of Radiology, McMaster University, Hamilton, Ontario, Canada