Inclusion Criteria:  Patients presenting with acute ischemic stroke eligible, using standard criteria, to receive IV thrombolytics within 4.5 hours of stroke onset Patient's age is ≥18 years Intention to perform endovascular thrombectomy Imaging inclusion criteria Arterial occlusion on CTA or MRA of the ICA, M1, M2 or basilar artery  Exclusion Criteria:  Intracranial hemorrhage (ICH) identified by CT or MRI Rapidly improving symptoms at the discretion of the investigator Pre-stroke mRS score of ≥ 4 (indicating previous disability) Hypodensity in >1/3 MCA territory or equivalent proportion of basilar artery territory on non-contrast CT Contraindication to imaging with contrast agents Any terminal illness such that patient would not be expected to survive more than 1 year Any condition that, in the judgment of the investigator could impose hazards to the patient if study therapy is initiated or affect the participation of the patient in the study. Pregnant or lactating women