1 Department of Pediatrics, Referral Center for Sickle Cell Disease, CHIC Hospital, Paris XII University, Créteil, France. Electronic address: francoise.bernaudin@chicreteil.fr.
2 Medical Imaging Department, Referral Center for Sickle Cell Disease, CHIC Hospital, Paris XII University, Créteil, France.
3 Biostatistics and Clinical Epidemiology, Center of Research on Epidemiology and Biostatistics Sorbonne Paris Cité, Paris Diderot University, Saint Louis, Paris, France.