Validation of a novel CT perfusion software compared to RAPID in stroke patients receiving endovascular therapy

Accurate estimate of ischemic core volume (ICV) and penumbra volume (PV) is important in decision-making for endovascular therapies (EVT) and predicting the patient's clinical outcome. In this study, we compared the performance of a novel automated CT perfusion software UGuard and the Rapid Processing of Perfusion and Diffusion (RAPID). UGuard and RAPID had strong agreement with regard to ICV (ICC 0.92, 95% CI 0.89 - 0.94) and PV (ICC 0.8, 95% CI 0.73 - 0.85) measurements. ICVs measured by UGuard or RAPID were similar in predicting favorable outcome (AUC 0.72 vs. 0.70, P = 0.43), with UGuard measurements having higher specificity. After adjusting for significant clinical covariates, the predictive performance of favorable outcome was excellent for each of the six models incorporating ICV and PV, and the model which incorporated ICV and PV measured by UGuard software package showed the best predictive performance. We concluded that the ICV and PV of CT perfusion images measured by UGuard software package, as well as the capacity to predict favorable outcome of patients following EVT, were comparable to RAPID.