1. Departments of Neurosurgery, Vanderbilt University Medical Center, Poughkeepsie, New York
2. Departments of Neurosurgery, Vanderbilt University Medical Center and Baptist Hospital, Nashville, Tennessee
3. Departments of Radiology, Baptist Hospital and Vanderbilt University Medical Center, Nashville, Tennessee
4. Department of Neurosurgery, Vassar Brothers Hospital Poughkeepsie, New York