Cerebral infarction by proximal occlusion of the anterior circulation is common with major personal and societal consequences.

MRI is the gold standard for exploring stroke, especially ischemic, and a number of biomarkers on initial MRI (before reperfusion) are predictive of neurological prognosis. However, their spatiotemporal evolution in the suites of reperfusion is unclear.

Close monitoring by MRI would make it possible to precisely know the tissue, vascular and microvascular evolution of the infarct area and the penumbra after reperfusion, and thus to characterize MRI biomarkers associated with efficient tissue reperfusion.

The aim of the MR-Reperfusion study is to characterize new MRI biomarkers of efficient tissue reperfusion.

Inclusion Criteria:

• To be over 18 year-old
• Perfusion MRI assessment on admission;
• Admission for an acute infarction of the anterior circulation with proximal occlusion (tandem, distal internal carotid, or M1 segment of the middle cerebral artery);
• Initial mTICI = 0-1 on the initial angiography before treatment;
• Patient in complete autonomy (mRS ≤ 2) before the onset of symptoms;
• Mechanical thrombectomy (in combination or not with intravenous thrombolysis), within the first 6 hours of the onset of symptoms, or within 24 hours in case of clinical-radiological or radiological mismatch;
• Success of reperfusion estimated by an mTICI = 3 at the end of the procedure;
• Availability of MRI within 3 hours of angiographic reperfusion;
• To be able to understand the instructions given;
• Written consent given by the patient or a trusted person;
• To be enrolled in a social security plan;

Exclusion Criteria:

• Posterieur circulation obstruction;
• 3 months follow-up impossible with the completion of the MRI;
• Subject under a measure of legal protection