Magnetic resonance imaging vs computed tomography for baseline imaging evaluation in acute basilar artery occlusion

The optimal imaging modality, magnetic resonance imaging (MRI) or computed tomography (CT), for identifying good treatment candidates among patients with acute basilar-artery occlusion (BAO) remains unclear.

This was a post hoc analysis of the ATTENTION trial. Patients were categorized into MRI or CT groups according to the baseline imaging modality. The primary outcome was mRS 0-3 at 90 days. The secondary outcomes included mRS score shift on an ordinal scale, early neurological deterioration, time from stroke onset to arterial puncture, and time from onset to randomization. The safety outcome was mortality within 90 days. Clinical outcomes and workflow times were compared between the two groups.

Among 340 patients (CT: n = 277; MRI: n = 63), baseline imaging was not significantly associated with 90-day mRS 0-3 in the overall cohort (OR 0.99, 95% CI 0.50-1.95; P = 0.976). It remained highly consistent across both the endovascular treatment and best medical management subgroups. Baseline MRI assessment was not associated with significant workflow delays compared with CT, including time from stroke onset to randomization (mean difference [MD] 5.23 min; P = 0.843) and time to puncture (MD 13.16 min; P = 0.701). Furthermore, the association between imaging modality and outcomes was consistent across different time windows.

In patients with acute BAO, we did not observe evidence supporting the preferential use of MRI over CT as the primary imaging strategy for patient selection. Conventional imaging appears sufficient as a first-line tool for selecting patients in clinical practice.