MRI before intraarterial therapy in ischemic stroke: feasibility, impact, and safety
Intraarterial therapy (IAT) in acute stroke is increasingly used to recanalize major vessel occlusions, but recent trials failed to show significant benefit compared to intravenous thrombolysis, highlighting need for appropriate patient selection. This article reports use of MRI diffusion weighted imaging (DWI) and perfusion imaging (PI) to select patients for IAT. Pre-op MRI were successfully obtained in 83.5% of patients, with average scan-to-groin time of 116 minutes for MRI and 142 minutes for CT. 138 patients were included with mean NIHSS of 17. TICI 2B or 3 reperfusion was achieved in 52%, and good outcome (Modified Rankin 0-2) at 90 days was achieved in 41%. Patients with DWI lesions > 70 mL had significantly worse outcomes. The only statistically significant treatment variable was recanalization rate: TICI 2b or 3 was 78.7% for good outcomes and 37% for poor outcomes. These data suggest that MRI is feasible for IAT patient selection, with a major caveat of time to intervention since the average 116 minutes to starting angio is much higher than the U.S. Comprehensive Stroke Center certification goal of 90 minutes from admission to recanalization.