[1] Univ Calif Los Angeles, Neurovasc Imaging Res Core, Los Angeles, CA 90095 USA
[2] Univ Calif Los Angeles, Comprehens Stroke Ctr, Geffen Sch Med, Los Angeles, CA 90095 USA
[3] Univ Calif Los Angeles, Dept Neurol, Geffen Sch Med, Los Angeles, CA 90095 USA
[4] West Virginia Univ, Charleston Area Med Ctr, Charleston, WV USA