1. Neurovascular Centre, Departments of Medical Imaging & Neurosurgery, St. Michael's Hospital, University of Toronto, Toronto, ON, Canada
2. Neuroendovascular Program, Massachusetts General Hospital & Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
3. Department of Radiology, Mayo Clinic, Rochester, MN, USA
4. Nuffield Department of Primary Care Health Sciences and Department for Continuing Education (EBHC program), Oxford University, Oxford, UK