[1] Washington Univ, Sch Med, E Bldg Imaging Ctr, Dept Neurol & Neurol Surg, St Louis, MO 63110 USA
[2] Washington Univ, Sch Med, Mallinckrodt Inst Radiol, St Louis, MO 63110 USA
[3] Washington Univ, Sch Med, Neurol Neurosurg Intens Care Unit, St Louis, MO 63110 USA
[4] Washington Univ, Sch Med, Lillian Strauss Inst Neurosci, Barnes Jewish Hosp St Louis, St Louis, MO 63110 USA