1. Department of Radiology, Hamilton Health Sciences McMaster University Hamilton Ontario Canada
2. Department of Diagnostic Imaging, Hamilton General Hospital Hamilton Health Sciences Hamilton Ontario Canada
3. Department of Diagnostic Imaging, Juravinski Hospital and Cancer Centre Hamilton Health Sciences Hamilton Ontario Canada
4. Department of Diagnostic Imaging St. Joseph's Healthcare Hamilton Hamilton Ontario Canada
5. Department of Radiology and Epidemiology University of Ottawa Canada
6. Ottawa Hospital Research Institute Clinical Epidemiology Program Ontario Canada