[1] Scripps Res Inst, Dept Mol & Expt Med, La Jolla, CA 92037 USA
[2] Scripps Res Inst, Div Hematol & Med Oncol, La Jolla, CA 92037 USA
[3] Univ Calif San Francisco, Med Ctr, Dept Neurosurg, Div Intervent Neurovasc Radiol, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, Med Ctr, Dept Radiol, Div Intervent Neurovasc Radiol, San Francisco, CA 94143 USA
[5] Univ Calif San Francisco, Med Ctr, Dept Radiol, Div Diagnost Neuroradiol, San Francisco, CA 94143 USA
[6] Univ Calif San Francisco, Med Ctr, Dept Neurol, Div Diagnost Neuroradiol, San Francisco, CA 94143 USA
[7] Cleveland Clin Fdn, Dept Neurol, Cleveland, OH 44195 USA
[8] Tufts Univ New England Med Ctr, Dept Neurol, Boston, MA USA
[9] McMaster Univ, Hamilton Civ Hosp, Res Ctr, Hamilton, ON, Canada