IntroductionComputed tomography perfusion (CTP) has played an important role in patient selection for mechanical thrombectomy (MT) in acute ischemic stroke. We aimed to investigate the agreement between perfusion parametric maps of 3 software packages – RAPID (RapidAI‐IschemaView), Viz CTP(Viz.ai), and e‐CTP(Brainomix) – in estimating baseline ischemic core volumes of near completely/completely reperfused patients.MethodsWe retrospectively reviewed a prospectively maintained MT database to identify patients with anterior circulation large vessel occlusion strokes (LVOS) involving the internal carotid artery or middle cerebral artery M1‐segment and interpretable CTP maps treated during September 2018 to November 2019. A subset of patients with near‐complete/complete reperfusion (expanded thrombolysis in cerebral infarction [eTICI] 2c–3) was used to compare the pre‐procedural prediction of final infarct volumes.ResultsIn this analysis of 242 patients with LVOS, RAPID and Viz CTP relative cerebral blood flow (rCBF) < 30% values had substantial agreement (ρ = 0.767 [95% confidence interval [CI] = 0.71–0.81]) as well as for RAPID and e‐CTP (ρ = 0.668 [95% CI = 0.61–0.71]). Excellent agreement was seen for time to maximum of the residue function (T_max) > 6 seconds between RAPID and Viz CTP (ρ = 0.811 [95% CI = 0.76–0.84]) and substantial for RAPID and e‐CTP (ρ = 0.749 [95% CI = 0.69–0.79]). Final infarct volume (FIV) prediction (n = 136) was substantial in all 3 packages (RAPID ρ = 0.744; Viz CTP ρ = 0.711; and e‐CTP ρ = 0.600).ConclusionPerfusion parametric maps of the RAPID, Viz CTP, and e‐CTP software have substantial agreement in predicting final infarct volume in near‐completely/completely reperfused patients. ANN NEUROL 2023