[1] Univ Virginia Hlth Syst, Dept Radiol & Med Imaging, Charlottesville, VA 22908 USA
[2] Univ Virginia Hlth Syst, Dept Neurosurg, Charlottesville, VA 22908 USA
[3] Advocate Neurovasc Ctr, Oak Lawn, IL USA
[4] Borgess Brain & Spine Inst, Kalamazoo, MI USA
[5] Tulane Univ, Dept Neurol Surg, New Orleans, LA 70118 USA
[6] Crouse Radiol Associates Med Imaging, Syracuse, NY USA