Comparative validation of automated perfusion analysis software for ischemic penumbra estimation and EVT decision-making.

Background: While computed tomography perfusion is widely used in acute stroke imaging, magnetic resonance perfusion-weighted imaging (PWI) offers superior spatial resolution and tissue specificity, particularly when combined with diffusion-weighted imaging (DWI). However, no prior study has systematically compared automated PWI analysis platforms. This study aims to evaluate the performance of a newly developed software (JLK PWI) against the established RAPID platform in terms of volumetric agreement and clinical decision concordance. Methods: This retrospective multicenter study included 299 patients with acute ischemic stroke who underwent PWI within 24 h of symptom onset. Volumetric agreement between RAPID and JLK PWI was assessed using concordance correlation coefficients (CCC), Bland-Altman plots, and Pearson correlations. Agreement in endovascular therapy (EVT) eligibility was evaluated using Cohen's kappa based on DAWN and DEFUSE-3 criteria. Results: The mean age was 70.9 years, 55.9% were male, and the median NIHSS score was 11 (IQR 5-17). The median time from the last known well to PWI was 6.0 h. JLK PWI showed excellent agreement with RAPID for ischemic core (CCC = 0.87; p < 0.001) and hypoperfused volume (CCC = 0.88; p < 0.001). EVT eligibility classifications based on DAWN criteria showed very high concordance across subgroups (κ = 0.80-0.90), and substantial agreement was observed using DEFUSE-3 criteria (κ = 0.76). Conclusion: JLK PWI demonstrates high technical and clinical concordance with RAPID, supporting its use as a reliable alternative for MRI-based perfusion analysis in acute stroke care.