1. Department of Neurosurgery, Carle Foundation Hospital, University of Illinois College of Medicine at Urbana/Champaign, Urbana/Champaign, Illinois
2. Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
3. Medical Scholars Program, University of Illinois College of Medicine at Urbana/Champaign, Urbana/Champaign, Illinois
4. Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
5. Department of Neurosurgery, University of Texas Medical School at Houston, Houston, Texas