1. Department of Radiology, Division of Neuroradiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., MLC 5031, Cincinnati, OH 45229.
2. Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH.
3. Department of Radiology, Neuroradiology Unit, Great Ormond Street Hospital for Children, NHS Trust, London, UK.
4. Department of Radiology, Neuroradiology Unit, Gemelli University Hospital, Rome, Italy.