Predictive Value of CTP in Spatially and Volumetrically Identifying Ischemic Penumbra against Final Infarct Size in Anterior Circulation Stroke with and without Successful Reperfusion

BACKGROUND AND PURPOSE: CTP is important for acute ischemic stroke imaging and treatment, but defining the ischemic penumbra and infarct core remains debated. This study examined the relationship between initial hypoperfused tissue and final infarct in patients with acute anterior circulation occlusion, stratified by reperfusion status, to assess CTP’s predictive spatial and volumetric accuracy and re-evaluate its role in prognostication, nuanced clinical decision-making, and novel pathophysiology research in the new large core era.

MATERIALS AND METHODS: This retrospective single-center study included patients diagnosed with anterior circulation acute ischemic stroke who underwent CTP between May 2021 and February 2024. Initial imaging and follow-up NCCT scans were automatically co-registered. CTP-derived ischemic core and penumbra segmentations were compared with manually segmented final infarcts on follow-up imaging. Groups with (endovascular thrombectomy [EVT] with modified TICI score ≥ 2b) and without successful reperfusion (no or unsuccessful EVT) were compared by using the Dice similarity coefficient (DSC) for spatial alignment and Spearman correlation for volumetric agreement.

RESULTS: One hundred twenty-one patients were included (51% men, median age: 70 years, median NIHSS score: 14). Successful reperfusion was achieved in 37 patients, while 84 received no or unsuccessful EVT. Significant differences in regions of hypoperfusion were observed between the nonreperfusion and reperfusion groups concerning spatial alignment (median DSC: 0.52 versus 0.29; P < .001) and volumetric agreement (Spearman correlation between predicted and actual infarct volumes: 0.72 versus 0.07; P < .001).

CONCLUSIONS: CTP offers valuable insights into salvageable tissue in acute ischemic stroke, guiding treatments, predicting infarct volumes, aiding in future stroke pathophysiology research in the large core era, and potentially improving prognostication.