[1] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Neurovasc Res Lab,Dept Radiol, Charlestown, MA 02129 USA
[2] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Martinos Ctr Biomed Imaging, Charlestown, MA USA
[3] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Stroke Serv, Charlestown, MA USA
[4] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Neurosci Intens Care Unit,Dept Neurol, Charlestown, MA USA
[5] DHD Neurovasc Sorbonne Paris Cite, Lariboisiere Hosp, AP HP, Emergency Headache Ctr, Paris, France