1. Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto;
2. Division of Neurosurgery, The Hospital for Sick Children, Toronto;
3. Department of Neurosurgery, Loma Linda University Health, Loma Linda, California
4. Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto;
5. Division of Neurosurgery, Department of Surgery, University of Ottawa, Ottawa;
6. Division of Neuroradiology, Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada; and