Background Many new stroke trials are evaluating the utility of perfusion imaging for patient selection within certain time constraints. There is evidence that patients with a delayed (>12 h) clinical–diffusion mismatch have poor clinical outcomes. We present our experience utilizing perfusion imaging to triage patients for endovascular therapy irrespective of time constraints.

Methods 53 patients were treated over the past 2 years utilizing presenting National Institutes of Health Stroke Scale (NIHSS), anatomic imaging and perfusion information. Patients were excluded if they had a hemorrhage or significant completed stroke (>1/3 middle cerebral artery territory volume) on CT or cerebral blood volume maps. If perfusion imaging was limited, as in some basilar occlusion cases, then the clinical examination (NIHSS) was used. The median time to treatment from symptom onset of the patient cohort was then determined and patients were divided into two groups. Clinical outcomes were then documented and subgroup analysis was performed.

Results The mean time to treatment was 10.36 h and the median was 6.13 h (range 1.75–72 h), suggesting several patients were treated far beyond 6 h. Utilizing a 6 h time point to identify two separate groups yielded 26 patients treated before 6 h and 27 patients treated more than 6 h from symptom onset. Angiographically, TIMI2 or better flow was restored 96% of the time. Patient outcomes in those treated less than 6 h compared with more than 6 h showed modified Rankin Score (mRS) of 0–2 in 36% and 37%, respectively, and mRS 0–3 in 56% and 52%, respectively.

Conclusion Utilization of perfusion based techniques is a viable clinical strategy for identifying acute stroke patients for endovascular therapy. Clinical outcomes can be obtained that are similar to those of clinical trials, irrespective of time constraints in appropriately selected patients.