The main purpose of this study will be to evaluate the prognostic value at 3 months of life of brain perfusion MRI determined by Arterial Spin Labeling technique in the first week of life of term newborns with hypoxic-ischemic encephalopathy requiring management in neonatal intensive care unit.

Hypoxic-ischemic encephalopathy is the result of birth asphyxia due to transitory cerebral blood flow drop during perinatal period. It is the leading cause of neonatal encephalopathy, and thus a major cause of perinatal mortality, morbidity and adverse neurodevelopmental outcome. Usual care brain MRI is critically important in the diagnosis and prognosis. Lasting about 30 to 40 minutes, MRI exam includes successive sequences providing complementary information but none relatively to brain perfusion. Perfusion MRI without contrast media injection is possible using Arterial Spin Labeling (ASL) sequence. ASL is highly suitable for neonates, noninvasiveness, and lasts only 5 minutes. However, only one study assessed ASL as a prognostic factor. The purpose of the study is therefore to perform ASL sequence within usual care brain MRI.

Inclusion Criteria:

• neonates with a term ≥ 36 weeks of amenorrhea and birth weight ≥ 1800 g.

• presenting with perinatal asphyxia defined as combination of:

  • an acute perinatal event (such as placental abruption, cord prolapse, and/or severe foetal heart rate abnormalities);

  • and at least one of the following criteria:

    • Apgar score ≤ 5 at 10 minutes of life,
    • mask ventilation or intubation at 10 minutes of life,
    • metabolic acidosis defined as pH < 7 or base deficit ≥ 16 mmol/L or lactates ≥ 11 mmol/L within the first 60 minutes of life on cord or other arterial venous or capillary blood sample.

• patient treated or not with therapeutic hypothermia for 72 hours.

• affiliated patient or beneficiary of a social security scheme.

• informed and signed parental consent.

Exclusion Criteria:

• perinatal arterial ischemic stroke.
• congenital neuro-metabolic disorder.
• severe malformative abnormalities.
• MRI contra-indication.
• Poor understanding of the holders of parental authority