Inclusion Criteria:  Minor patients aged 0 to 18 with acute or chronic arterial disease: diagnosis of Moya-moya, diagnosis of sickle cell disease, acute and chronic arterial infarction. Necessity of diagnostic MR with standard ASL sequences for the care. Holders of parental authority and patients informed and not opposed to their participation in the study.  Exclusion Criteria:  Usual contraindications to MR. Movement during ASL / eASL sequences.