The role of brain CT perfusion in acute ischemic stroke patients in the early time window

Introduction: International guidelines recommend only non-contrast CT (NCCT) for eligible acute ischemic stroke (AIS) patients receiving intravenous thrombolysis (IVT) in the early time window. We aim to assess the potential role of advanced neuroimaging in predicting radiological and clinical outcomes in AIS patients treated with IVT within 4.5 h of stroke onset. Methods: Between July 2021 and August 2022, 262 AIS patients within 4.5 h underwent multimodal CT protocol (NCCT, CT-perfusion using RAPID software, multiphasic CT-Angiography). Demographic, clinical, and neuroradiological data, including CT-perfusion parameters were collected. Final infarct volume (FIV) and 3-month clinical outcomes using modified Rankin Scale (mRS) were assessed. Results: Patients with unfavourable 3-month outcome (mRS 3-6) were older, had higher baseline National Institutes of health Stroke Scale (NIHSS), a longer onset-to-needle time and a higher percentage of Baseline Alberta stroke programme early CT score (ASPECTS) <= 9. All perfusional parameters were notably more impaired in patients with 3-month unfavourable outcome. Patients with 3-month mRS 3-6 had a larger FIV at follow-up (p < 0.001). In multivariable binomial logistic regression model ischemic core as relative Cerebral Blood Flow (rCBF) <30 % (p < 0.001), baseline NIHSS (p = 0.020) and TICI 0-2a (p = 0.005) independently predicted FIV > 10 ml. Age (p < 0.001), baseline NIHSS (p = 0.026), onset to needle time (p = 0.004) and rCBF<30 % (p = 0.005) independently predicted 3-month mRS 0-2. In multivariable ordinal logistic regression model rCBF<30 % was an independent predictor of 3-month mRS 3-6 (OR 1.04, p = 0.001). Conclusion: In the early time window for IVT, the rCBF<30 % as ischemic core is a useful early predictor of FIV and 3-month clinical outcome.