1. Division of Interventional Neuroradiology, Department of Diagnostic Radiology, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada
2. Division of Neuroradiology, Department of Diagnostic Radiology, University of British Columbia, Vancouver, BC, Canada
3. Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland
4. School of Medicine, Faculty of Health Sciences Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland