不同时间窗溶栓治疗急性缺血性卒中患者CT灌注成像核心梗死的可逆性研究

Reversibility of ischemic core defined by CT perfusion imaging in acute stroke patients receiving thrombolysis within different time windows

目的探讨不同时间窗接受静脉溶栓治疗的急性缺血性卒中(AIS)患者的CT灌注成像所定义的基线核心梗死的可逆性及其影响因素。方法回顾性分析于2016年5月至2018年12月在丽水市人民医院神经内科接受静脉溶栓治疗的AIS患者临床和影像学资料,所有入组的患者均完成溶栓前颅脑多模式CT和溶栓后24~48 h多模式MRI复查。基于CT灌注图像利用MIStar软件定量评估基线核心梗死体积[相对脑血流量(rCBF)<30%的低灌注区],同时基于复查的弥散加权成像图像评定最终的核心梗死体积。本研究中将基线核心梗死体积-最终核心梗死体积≥5 ml定义为基线核心梗死具有可逆性。比较分析核心梗死可逆组和不可逆组患者的临床和影像学特征,并经二元Logistic回归分析核心梗死可逆性的影响因素。结果共97例AIS患者入组本研究,其中实现血管再通64例(66%),基线核心梗死可逆51例(53%)。实现血管再通的患者从发病到溶栓治疗时间(ONT)<3.0 h、3.0~4.5 h、4.6~6.0 h和>6.0 h组表现核心梗死可逆性的比例分别为76%(26/34)、71%(17/24)、2/5和0(0/1),而在责任血管未再通组也有6例患者出现了核心梗死的可逆性改变,其中ONT<3.0 h组4例(4/12),3.0~4.5 h组2例(2/12)。经Spearman相关分析发现,发生可逆性梗死的体积大小与基线核心梗死体积大小呈高度正相关(r=0.805,P<0.001)。二元Logistic回归分析结果显示,高血压病史、ONT和血管再通是核心梗死出现可逆性改变的独立预测因素。结论基于CT灌注成像(rCBF<30%)所定义的核心梗死不适用于发病时间窗6.0 h之内的患者,如能在该时间窗内实现闭塞血管的再通,大部分患者可发生核心梗死的可逆性改变,其影响因素除血管再通状况还包括高血压病史和ONT。

Objective To investigate the reversibility of ischemic core defined by CT perfusion imaging in acute ischemic stroke(AIS)patients receiving intravenous thrombolysis within different time windows and influencing factors.Methods The data of AIS patients who received intravenous thrombolysis in the Department of Neurology of Lishui People′s Hospital from May 2016 to December 2018 were retrospectively reviewed.All patients had finished multi-model CT imaging before thrombolysis and multi-model MRI examination 24-48 hours after thrombolysis.The baseline ischemic core volume(hypoperfusion area with relative cerebral blood flow(rCBF)<30%)was quantitatively assessed based on CT perfusion images using MIStar software,and the final ischemic core volume was assessed based on diffusion weighted imaging acquired 24-48 hours after thrombolysis.The reversibility of ischemic core was defined as baseline ischemic core volume-the final infarct volume≥5 ml.Then the clinical and imaging features of the patients between reversible group and irreversible group were compared,and the predictors of ischemic core reversibility were analyzed by binary Logistic regression analysis.Results Finally,97 patients were enrolled in the present study,of which 64(66%)patients achieved successful recanalization,51(53%)patients with reversible baseline ischemic core.For patients with recanalization,the incidence of reversibility was 76%(26/34),71%(17/24),2/5 and 0(0/1)in patients with time window from onset to thrombolysis(ONT)<3.0 h,3.0-4.5 h,4.6-6.0 h,and>6.0 h,respectively.In the non-recanalization group,six patients were also showed with ischemic core reversibility,including 4(4/12)in the ONT<3.0 h group and 2(2/12)in the ONT 3.0-4.5 h group.It was found that the reversible volume was positively correlated with baseline ischemic core volume(r=0.805,P<0.001)by Spearman correlation analysis.Finally,binary Logistic regression analysis revealed that the history of hypertension,ONT and recanalization were independent predictors of reversible changes of baseline ischemic core.Conclusions The ischemic core defined by CT perfusion imaging(rCBF<30%)was considerably inaccurate for patients with ONT<6.0 h.If recanalization could be achieved within this time window,most of the patients would manifest with ischemic core reversibility,the predictors of which also included hypertension history and ONT.