1. Division of Interventional Neuroradiology, Department of Radiology, Massachusetts General Hospital, Boston, MA
2. Department of Neurology, Massachusetts General Hospital, Boston, MA
3. Department of Neurology, Emory University School of Medicine, Atlanta, GA
4. Department of Emergency Medicine, Massachusetts General Hospital, Boston, MA
5. Department of Anesthesia and Critical Care, Massachusetts General Hospital, Boston, MA
6. Wellstar Neurosurgery, Kennestone Hospital, Marietta, GA
7. Division of Diagnostic Neuroradiology, Massachusetts General Hospital, Boston, MA