Background: CT-perfusion (CTP) has a growing role in evaluating stroke. It can be performed easily following non-contrast CT and has advantages of accessibility and speed. Differentiation of salvageable ischemic penumbra may help identify patients most likely to benefit from reperfusion therapies. However, its utility within the first 6 hours after stroke has been controversial.

Methods : We retrospectively analyzed patients admitted to our stroke unit (terciary center) during 2017. We collected data obtained from initial imaging (Alberta Stroke Program Early CT Score (ASPECTS), arterial occlusion revealed by CT angiography (CTA), perfusion mismatch) and clinical data (on admission/at discharge NIHSS, age, sex, classic vascular risk factors and applied reperfusion therapies).

Results : A total of 521 patients were admitted to our stroke unit during 2017. 168 met the inclusión criteria (patients with acute neurological symptoms who were conducted a multiparametric CT scan with less tan six hours from onset). The mean time from symptom onset to CT imaging was 1,5 hours. 9% of patients had a non contrast CT ASPECTS of < 7 on arrival. 13,69% did not have any arterial occlusion revealed by CTA but showed perfusion alterations. Reperfusion therapies were performed in 78% (67,26% rtPA, 34,52% thrombectomy , 23,21%  thrombectomy + rtPA). In 14 patients (8,33%) CT perfusion helped in clinical decisión making. 3 patients were stroke mimics, and 11 patients had a non contrast CT ASPECT 5-6 on arrival. In this cases significant penumbra to core mismatch was used as selection criteria and helped decision making (6 underwent thrombectomy).
 
Conclusion: CTP can help decission making in a small group of patients, especially in those cases with non contrast CT ASPECT 5-6 despite a short time after stroke and also in stroke mimics.

ROLE OF PERFUSION CT SCAN IN ACUTE ISCHEMIC STROKE WITHIN 6 HOURS AFTER SYMPTOMS ONSET