1. Department of Neurosurgery, Children's Hospital of Pittsburgh and the University of Pittsburgh, Pittsburgh, Pennsylvania
2. Department of Neurology, Children's National Medical Center and the George Washington University, Washington, District of Columbia
3. Departments of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
4. Departments of Pathology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
5. Department of Statistics, St. Jude's Children's Research Hospital, Memphis, Tennessee
6. Department of Pediatrics, University of Southern California School of Medicine, Los Angeles, California