Abstract Number: Esoc2026a898 Time to Imaging and Reperfusion Status Modify Ct Perfusion Prediction of Malignant Cerebral Infarction

Abstract Background and aims Malignant cerebral infarction (MCI) is a life-threatening complication of large vessel occlusion (LVO). Baseline CT-perfusion (CTP) thresholds and ASPECTS predict MCI, but their performance may depend on time-to-imaging and reperfusion success. We evaluated whether these factors influence the predictive accuracy of baseline markers (ASPECTS, relative cerebral blood volume rCBV, relative cerebral blood flow rCBF) for MCI. Methods We retrospectively analyzed 249 patients with severe anterior circulation LVO and multimodal CT at admission. Patients were stratified into four groups by time-to-CTP (Early 3h vs. Late ≥3h) and reperfusion status (Successful, mTICI 2b–3 vs. Unsuccessful). MCI was defined by both clinical and radiological criteria. Predictive performance of ASPECTS, rCBV, and rCBF core volumes across thresholds (0–100% of contralateral values) was assessed using ROC area, sensitivity, specificity, positive predictive value (PPV), and F1-score. Results MCI occurred in 62/249 patients (25%). Time and reperfusion showed a strong interaction (p0.001): rates were 12% (Early+Successful), 32% (Early+Unsuccessful), 14% (Late+Successful), and 46% (Late+Unsuccessful). In the Early+Unsuccessful group, rCBV40% had higher predictive capacity than ASPECTS or rCBF. In the Late+Unsuccessful group, all three parameters reached high predictive values. In both reperfused subgroups, PPV for all baseline parameters dropped to 20–35% despite sensitivity 90%. Conclusions Baseline imaging prediction of MCI is strongly time- and reperfusion-dependent. rCBV is the most robust early marker of malignant evolution when reperfusion fails, whereas successful reperfusion essentially invalidates predictions derived from baseline cores. Conflict of interest Name of author: nothing to disclose