[1] Univ Maryland, Sch Med, Dept Diagnost Radiol & Nucl Med, Baltimore, MD USA
[2] Univ Alabama Birmingham, Dept Radiol, Birmingham, AL USA
[3] New York Univ Langone Med Ctr, Dept Radiol, New York, NY USA
[4] Albert Einstein Coll Med, Dept Radiol, Bronx, NY USA
[5] Massachusetts Gen Hosp, Dept Neurol, Boston, MA USA
[6] Vanderbilt Univ, Med Ctr, Dept Radiol & Radiol Sci, Nashville, TN USA
[7] Washington Univ, Sch Med, Mallinckrodt Inst Radiol, St. Louis, MO USA