1. Cerebrovascular and Endovascular Division, Tufts-New England Medical Center, Boston, Massachusetts (Schirmer, Malek, Hoit)
2. Department of Radiology, Tufts-New England Medical Center, Boston, Massachusetts (Kwan)
3. Division of Spinal Surgery, Department of Neurosurgery, Tufts-New England Medical Center, Boston, Massachusetts (Weller)