MRI versus CT before endovascular thrombectomy in the early time window: A systematic review and meta-analysis

Selection of acute stroke patients for endovascular thrombectomy (EVT) within 6 h from symptom onset can be done using MRI or CT. However, association of either imaging modality with better clinical outcomes or shorter workflow times is still not fully understood. We searched Medline and Ovid-Embase for studies comparing outcomes and workflow metrics between patients selected for EVT using CT or MRI from inception to November 30, 2024. The primary outcome was the association of imaging modality with functional independence (modified Rankin Scale score, 0-2) at 90-days and workflow metrics. Pooled odds ratios with 95% CIs were calculated using a random-effects model. Nine studies with 11,202 patients (3018 with MRI vs 8184 with CT) were analysed. Patients selected with MRI had similar odds of 90-day mRS 0-2 (adjusted odds ratio aOR 1.1195% CI 0.84-1.47) and lower mortality (aOR 0.6695% CI 0.57-0.76) compared to those selected with CT. Door-to-imaging time (mean difference MD 11.2 min 95% CI 4.8 to 18.4) and door-to-intravenous thrombolysis initiation time (MD 10.1 min 95% CI 4.9 to 15.2) were longer in patients selected with MRI. However, door-to-arterial puncture time was similar between both groups (MD 6.8 min 95% CI -4.6 to 18.1). In stroke patients undergoing EVT within 6 h from symptom onset, MRI before EVT could be a feasible alternative to CT without significant delays from door to puncture time. Randomized trials are needed before these findings can be generalized.