1. Reference Center for Sickle Cell Disease, Department of Pediatrics, and
2. Medical Imagerie, Department of Radiology, Intercommunal Créteil Hospital, Créteil, France;
3. Department of Statistics, St-Louis Hospital, Paris, France;
4. Pediatrics, University of Southern California, Los Angeles; and
5. Hematology, Molecular Biology, Tenon Hospital, Paris, France