[1] Univ Hlth Network, Div Neuroradiol & Joint Dept Med Imaging, Toronto, ON M5T 2S8, Canada
[2] Toronto Western Hosp, Toronto, ON M5T 2S8, Canada
[3] Natl Neurosci Inst, Dept Neuroradiol, Singapore 308433, Singapore
[4] Univ Toronto, Dept Med Imaging, Toronto, ON M5T 1W7, Canada
[5] Toronto Western Hosp, Div Neurosurg, Toronto, ON M5T 2S8, Canada
[6] Univ Toronto, Sprott Dept Surg, Toronto, ON M5G 2C4, Canada
[7] Toronto Western Hosp, 399 Bathurst St, Toronto, ON M5T 2S8, Canada