Abstract: Objective Parenchymal hematoma （PH） is a severe type of hemorrhagic transformation and is associated with poor outcomes in patients with acute ischemic stroke after endovascular thrombectomy treatment. This study explores the relationship between hypoperfusion intensity ratio （HIR） from CT perfusion imaging with postoperative PH and clinical outcomes. Methods We analyzed the clinical and imaging data of patients with acute anterior circulation large vessel occlusion treated with endovascular intervention in our stroke center from December 2020 to December 2022. HIR was calculated as the ratio of severe hypoperfusion area volume （Tmax>10 seconds） to hypoperfusion area volume （Tmax>6 seconds） from head CT perfusion imaging. The type of hemorrhagic transformation after endovascular thrombectomy treatment was determined according to Heidelberg grading criteria. We analyzed the relationship between clinical, and imaging data with postoperative HT and clinical outcomes at discharge. Results Fifty-five patients with acute anterior circulation large vessel occlusion were included in the study. Twenty-one patients （38.2%） developed HT after thrombectomy treatment, including nine with PH. HIR at admission was significantly higher in the PH group than in the non-PH group （0.58 vs. 0.33, P=0.010）. HIR was significantly higher in the poor clinical outcome group （modified Rankin Scale 3~6 points） than in the good outcome group （0.47 vs. 0.25, P<0.001）. In addition, atrial fibrillation, NIHSS score at admission, blood glucose, neutrophil-to-platelet ratio, cerebral blood flow <30%, Tmax>10 seconds, and PH after endovascular thrombectomy were significantly associated with poor clinical outcomes. HIR（OR=1132.791, 95%CI： 7.979~160 828.706, P=0.005）was one ofthe independent factors for poor clinical outcomes. Conclusion HIR at admission is significantly associated with PH after endovascular thrombectomy, and it is an effective imaging marker for poor clinical outcomes after endovascular thrombectomyfor patients with acute anterior circulation large vessel occlusion.

Key words: acute ischemic stroke, endovascular treatment, CT perfusion imaging, hypoperfusion intensity ratio, hemorrhagic transformation

摘要： 目的 实质脑血肿（PH）是严重类型的出血转化,是急性脑梗死血管内介入再通治疗后效果不佳的重要原因。探讨CT灌注成像的低灌注强度比值（HIR）与介入取栓治疗后PH和临床结局的关系。方法 分析2020年12月至2022年12月我院卒中中心血管内介入治疗急性前循环卒中患者数据。取栓前行头颅CT灌注成像,确定HIR为严重低灌注区体积（Tmax>10 s）与低灌注区体积（Tmax>6 s）比值。按Heidelberg分级明确取栓治疗后出血转化类型。分析临床和影像学资料与取栓后出血转化及出院时临床结局的关系。结果 55例急性前循环卒中患者纳入研究。21例（38.2%）患者取栓治疗后出现颅内出血转化,其中9例为PH。治疗前HIR在PH组明显高于无PH组（0.58 vs. 0.33,P=0.010）。HIR在出院临床结局不佳组（mRS 3~6分）明显高于临床结局良好组（0.47 vs. 0.25,P<0.001）。此外,房颤、入院NIHSS评分、血糖、中性粒细胞与血小板比值、脑血流量<30%、Tmax>10 s、PH类型出血转化与临床结局不佳显著相关。HIR是临床结局不佳的独立危险因素之一（OR=1132.791,95%CI：7.979~160 828.706, P=0.005）。结论 治疗前HIR与急性前循环卒中介入再通治疗后PH类型出血转化显著相关,是血管内介入再通治疗后临床结局不佳的预警标志物。

关键词: 急性缺血性脑卒中, 血管内介入治疗, CT灌注成像, 低灌注强度比, 出血转化