1. Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts;
2. Department of Medical Imaging, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada;
3. Department of Neurosurgery, University of Alabama at Birmingham, Alabama;
4. Department of Neurosurgery, State University of New York at Buffalo, New York;
5. Department of Interventional Neuroradiology, University of Florence, Italy;
6. Division of Diagnostic and Therapeutic Neuroradiology, St. Michael’s Hospital, Toronto;
7. Department of Diagnostic and Therapeutic Neuroradiology, Toulouse University Hospital, Toulouse, France; and
8. Department of Neurosurgery, Yale School of Medicine, New Haven, Connecticut