Sickle Cell Anemia and Cerebral Microcirculation : Multimodal Exploration

Determinants of Cerebral Oxygenation and Perfusion in SCA Children Based on Combined ASL MRI, NIRS and Hemorheological Investigation

The aim of this study is to evaluate determinants of cerebral oxygenation and perfusion at the microcirculatory level in children with sickle cell anemia (SCA) using combined novel investigational tools: Arterial Spin Labeling (ASL) perfusion MR (Magnetic Resonnance) imaging, brain Near Infra-Red Spectroscopy (NIRS) and red blood cell (RBC) rheological properties.

The investigators hypothesize that brain perfusion and/or oxygenation modifications may be evidenced in SCA children who have no microarteriopathy and may correlate with hemorheological abnormalities and impaired vasomotion. A multimodal approach designed to study a. cerebral perfusion and oxygenation, b. flow motion properties and c. blood rheological parameters might help to describe the different processes involved in cerebral ischemia.

Inclusion Criteria:

• SS or S-beta° genotype;
• age 6-16 years;
• steady state;
• normal TCD (Transcranial Doppler);
• parental study approval and written informed consent.

Exclusion Criteria:

• SC, Sbeta+, SD Punjab genotype
• history of overt stroke,
• intracranial or cervical arterial stenosis,
• abnormal TCD at the time of the study.