1. Department of Neurological Surgery, Loyola University Medical Center, Maywood, Illinois;
2. Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois;
3. University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania;
4. Department of Surgery, Division of Pediatric Neurosurgery, Ann & Robert H. Lurie Children’s Hospital, Chicago, Illinois; and
5. Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois