Accuracy of computed tomography perfusion-defined ischemic core and follow-up infarction after basilar artery thrombectomy

Purpose Accurate identification of computed tomography (CT) perfusion ischemic core in patients with basilar artery occlusion (BAO) on admission remains challenging despite its critical role in prognostic prediction and treatment decision-making. We aimed to define the optimal threshold for identifying the ischemic core by assessing agreement in lesion extent and spatial distribution using Syngo.via. Methods We retrospectively analyzed 91 patients with BAO who achieved successful recanalization after endovascular thrombectomy at our center. The ischemic core was estimated using the following thresholds: cerebral blood flow (CBF) < 10 or 15 mL/100 g/min by Syngo.via, cerebral blood volume < 1.2 mL/100 mL by Syngo.via, and time to maximum > 10 s by RAPID. The Posterior Circulation Alberta Stroke Program Early CT Score was used to assess the extent of the infarction. Statistical analyses included the intraclass correlation coefficient (ICC) and receiver operating characteristic analyses. Results The CBF < 10 mL/100 g/min threshold demonstrated good agreement in extent with follow-up infarction (ICC: 0.81 [95% confidence intervals 0.72–0.87]), with overestimation or underestimation being the most uncommon ( n = 9). For the detection of midbrain, pontine, and cerebellar infarction, this threshold yielded the best performance with the area under the curve ranging from 0.79 (midbrain, 0.66–0.93; p < 0.001) to 0.90 (pons, 0.83–0.98; p < 0.001). Conclusion In patients with BAO after successful recanalization, the optimal threshold for the ischemic core was a CBF < 10 mL/100 g/min. This threshold may serve as a reliable imaging biomarker, aiding in the prediction of tissue outcomes and treatment decision-making.