MRI-Based Selection for Intra-Arterial Stroke Therapy

Background and Purpose— Recent studies demonstrate that an acute diffusion-weighted imaging lesion volume >70 cm 3 predicts poor outcome in patients with stroke. We sought to determine if this threshold could identify patients treated with intra-arterial therapy who would do poorly despite reperfusion. In patients with initial infarcts 70 cm 3 , all had poor outcomes despite a 50% recanalization rate with mean infarct growth of 114 cm 3 . These patients also had the largest mean transit time volumes ( P <0.04). Patients with initial infarct volumes <70 cm 3 who recanalized early had the best clinical outcomes ( P <0.008) with a 64% rate of modified Rankin Scale score ≤2 and the least infarct growth ( P <0.03) with mean growth of 18 cm 3 . Conclusion— This study supports the use of an acute diffusion-weighted imaging lesion volume threshold as an imaging selection criterion for intra-arterial therapy. It also confirms the importance of early reperfusion in selected patients.