[1] Univ Calgary, Dept Radiol & Clin Neurosci, Calgary, AB, Canada
[2] Univ Toronto, Fac Appl Sci & Engn, Toronto, ON, Canada
[3] Virginia Mason Med Ctr, Dept Radiol, Seattle, WA 98101 USA
[4] NYU, Sch Med, Dept Neurol, Div Neurointervent Radiol, New York, NY USA
[5] Harvard Med Sch, Massachusetts Gen Hosp, Dept Neurointervent Radiol, Boston, MA USA