1. Division of Neuroradiology, Joint Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada;
2. Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland;
3. Institute of Clinical Medicine, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland;
4. Division of Neurosurgery, Department of Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada;
5. Department of Neurosurgery, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada;
6. Department of Neuroradiology, National Neuroscience Institute, Singapore, Singapore
7. Department of Neuroradiology, Beaumont Hospital, Dublin, Ireland;