Computed tomography perfusion-defined ischemic core predicts functional outcome after basilar artery thrombectomy

Chen Pengjun¹Xia Li¹Yechao Huang¹Junguo Hui²Jie Rao³Wenya Zhang¹Lijun Shang⁴Xiao Chen¹Ruijie Gao¹Jinwei Zhou¹Qiao-Ling Ding⁵Shuiwei Xia^1*Jian Song Ji^1*

• ¹Zhejiang Key Laboratory of Imaging and Interventional Medicine, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui Hospital of Zhejiang University, Lishui, China
• ²The Second School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China
• ³Department of Neurology, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui Hospital of Zhejiang University, Lishui, China
• ⁴Department of Radiology, Jinyun County People's Hospital, Lishui, China
• ⁵Department of Radiology, Affiliated Hangzhou Xixi Hospital, Zhejiang University School of Medicine, Hangzhou, China

Purpose: This study aimed to determine the optimal threshold for computed tomography perfusion (CTP)-defined ischemic core in patients with basilar artery occlusion (BAO) that predicts functional outcome. Methods: A retrospective analysis was conducted on BAO patients who underwent endovascular thrombectomy at our stroke center between January 2018 and March 2024. Ischemic core was estimated using 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 (Tmax) > 10 seconds by RAPID. A favorable functional outcome was defined as a modified Rankin Scale score of 0-3 at 90-day post-onset. The Posterior Circulation Alberta Stroke Program Early computed tomography Score (pc-ASPECTS) was semi-quantified to assess ischemic changes. Statistical analysis included intraclass correlation coefficient (ICC) and receiver operating characteristic analyses. Results: A total of 85 patients were enrolled, and 39 (45.9%) had a favorable functional outcome. The ICC for pc-ASPECTS based on four core approaches between junior and senior observers ranged from 0.90 to 0.96. For the classification of favorable outcome, the volume and pc-ASPECTS core estimation approach (CBF < 10 mL/100 g/min by Syngo.via) had the best performance, with the largest area under the curve of 0.86 ([95% confidence intervals, 0.78-0.94]; P < 0.001) and 0.87 ([95% confidence intervals, 0.80-0.94]; P < 0.001), with a cut-off value of ≤2.2 (78.3%% sensitivity, 84.6% specificity), and ≥7 (92.3% sensitivity, 65.2% specificity). Conclusion: In BAO patients following successful recanalization, the volume and pc-ASPECTS core estimation approach (CBF < 10 mL/100 g/min by Syngo.via) demonstrated the strongest predictive value for favorable functional outcomes.