[1] Harvard Univ, Massachusetts Gen Hosp, Sch Med, NeuroEndovasc Program, Boston, MA 02114 USA
[2] Mecklenburg Radiol Associates PA, Charlotte, NC USA
[3] Weill Cornell Med Coll, Dept Radiol, New York, NY USA
[4] Hackensack Univ, Med Ctr, Hackensack, NJ USA
[5] South Texas Radiol Grp, San Antonio, TX USA
[6] Pain Management Ctr Paducah, Paducah, KY USA
[7] Univ Louisville, Dept Anesthesiol & Perioperat Med, Louisville, KY 40292 USA