P1421: THE EFFECT OF HEMATOPOIETIC STEM CELL TRANSPLANTATION ON CEREBRAL PERFUSION AND OXYGEN METABOLISM IN PATIENTS WITH SICKLE CELL DISEASE - Liza Afzali-Hashemi; Elisabeth Dovern; Koen P. A. Baas; Anouk Schrantee; Aart J. Nederveen; Erfan Nur; Bart J. Biemond (HemaSphere, 2023)