Inclusion Criteria1. Patients presenting with acute ischemic stroke eligible using standard criteria to receive IV thrombolysis within 4.5 hours of stroke onset
2. Patient's age is ≥18 years
3. Intra-arterial clot retrieval treatment can commence (arterial puncture) within 6 hours of stroke onset.
4. Arterial occlusion on CTA or MRA of the ICA, M1, M2 or basilar artery.
Exclusion Criteria1. Intracranial hemorrhage (ICH) identified by CT or MRI
2. Rapidly improving symptoms at the discretion of the investigator
3. Pre-stroke mRS score of ≥ 4 (indicating previous disability)
4. Hypodensity in >1/3 MCA territory or equivalent proportion of basilar artery territory on non-contrast CT
5. Contra indication to imaging with contrast agents
6. Any terminal illness such that patient would not be expected to survive more than 1 year
7. 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.
8. Pregnant women