MRI before intraarterial therapy in ischemic stroke: feasibility, impact, and safety.

Intraarterial therapy (IAT) in acute ischemic stroke is effective for opening occlusions of major extracranial or intracranial vessels. Clinical efficacy data are lacking pointing to a need for proper patient selection. We examined feasibility, clinical impact, and safety profile of magnetic resonance imaging (MRI) for patient selection before IAT. In this single-center study, we collected epidemiologic, imaging, and outcome data on all intraarterial-treated patients presenting with anterior circulation occlusions at our center from 2004 to 2011. Magnetic resonance imaging was the first imaging choice. Computer tomography (CT) was performed in the presence of a contraindication. We treated 138 patients. Mean age was 64 years and median National Institutes of Health Stroke Scale (NIHSS) was 17. Major reperfusion (thrombolysis in cerebral infarction (TICI) 2b+3) was achieved in 52% and good outcome defined as modified Rankin Scale (mRS) score 0 to 2 at 90 days was achieved in 41%. Mortality at 90 days was 10%. There was only one symptomatic hemorrhage. Recanalization, age, and stroke severity were associated with outcome. Preprocedure MRI was obtained in 83%. Good outcome was significantly associated with smaller diffusion-weighted imaging (DWI) lesion size at presentation and not with the size of the perfusion lesion. It is feasible to triage patients for IAT using MRI with acceptable rates of poor outcome and symptomatic hemorrhage.