Hyperacute stroke: Ultrafast MR imaging to triage patients prior to therapy

PURPOSE: To test diffusion and perfusion-weighted MR imaging techniques wit hin the extreme time constraints of stroke evaluation before therapy, and t hen, with MR imaging, stratify patients into those without ischemia, those with noncortical ischemia, and those with cortical ischemia. MATERIALS AND METHODS: T2-weighted turbo gradient- and spin-echo images and echo-planar diffusion- and perfusion-weighted images were obtained. Trace diffusion-weighted images and time-to-peak perfusion maps were automaticall y postprocessed and immediately available for interpretation. RESULTS: Forty-one patients with acute stroke symptoms underwent imaging wi thin 6 hours of symptom onset; 35 were eligible for the therapy protocol. T he mean time from entering the emergency department to beginning MR imaging was 45 minutes; the mean total MR imaging time was less than 15 minutes. I mmediate image analysis directly affected individual clinical management. F our patients showed evidence of no infarct; seven of lacunar infarct; and 2 4, of acute cortical infarct. Sixteen patients underwent angiography, thirt een had large-vessel occlusion, eleven were treated intraarterially,and in seven, recanalization was achieved. CONCLUSION: Echo-planar diffusion- and perfusion-weighted MR imaging for ac ute stroke is feasible and applicable before therapy decisions. Ultrafast M R imaging permitted immediate triage of 35 patients with symptoms of hypera cute stroke and thus helped avoid the risks from angiography and thrombolyt ic agents in some or spurred the judicious use of more aggressive intervent ion in others.