Accuracy and Variability of Spatial Localization of Infarct Core Predicted by CT Perfusion.

Abstract

Objective: In patients with acute ischemic stroke, CT perfusion (CTP)-derived infarct core is valuable for prognostication, triage and transfer decision-making, and for informing studies of emerging therapeutic targets. In this study, we compare the accuracy and variability of the infarct core predicted by 2 FDA-cleared CTP programs, using diffusion-weighted MRI (DWI) as the reference standard.

Methods: We analyzed 61 stroke patients who underwent admission CTP and DWI within 90 minutes. Infarct core was estimated using relative cerebral blood flow thresholds and compared with DWI-derived ground truth. After coregistration of CTP and DWI, Dice similarity coefficients were calculated to quantify the topographic concordance of the infarct core.

Results: The CTP-determined infarct core volumes were significantly correlated with DWI but demonstrated substantial variability and bias. Our results showed limited topographic overlap, with median dice scores of 0.367 (CTP-A) and 0.289 (CTP-B). However, in patients with larger infarcts (volumes ≥50 mL), CTP provides more reliable estimates of spatial agreement, reaching median Dice scores of 0.61 (CTP-A) and 0.47 (CTP-B).

Conclusions: Although these findings show a generally low accuracy of CTP estimation, they suggest that CTP may offer clinically meaningful insights for decision-making in the large-core setting and inform the design of future trials.