1 Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
2 Department of Interventional Radiology, Tower Health, Reading Hospital, West Reading, Pennsylvania.
3 Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205.
4 Department of Radiology, Our Lady of Lourdes Regional Medical Center, Lafayette, Louisiana.
5 Department of Radiology and Department of Neurosurgery, University of Michigan Hospitals, Ann Arbor, Michigan.
6 Charlotte Radiology, Carolinas Medical Center, Charlotte, North Carolina.
7 Department of CardioVascular and Interventional Radiology, Inova Alexandria Hospital, Alexandria, Virginia.