[1] Abbott NW Hosp, Dept Intervent Neuroradiol, Minneapolis, MN 55407 USA
[2] Washington Univ, Sch Med, Mallinckrodt Inst Radiol, Div Neuroradiol, St Louis, MO USA
[3] Univ Minnesota, Sch Med, Dept Intervent Neuroradiol, Minneapolis, MN 55455 USA
[4] Emory Univ, Dept Neurol Surg, Atlanta, GA 30322 USA
[5] Washington Univ, Sch Med, Dept Neurol Surg, St Louis, MO USA
[6] Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA
[7] Washington Univ, Sch Med, Neurol Neurosurg Intens Care Unit, St Louis, MO 63110 USA