MR定量磁敏感图评估急性缺血性卒中患者脑血氧饱和度变化对梗死进展的影响

Evaluation of the effect of cerebral oxygen saturation on infarct progression in patients with acute ischemic stroke based on MR quantitative magnetic susceptibility mapping

目的探讨急性缺血性卒中患者治疗前后脑血氧饱和度动态变化对梗死进展的影响。方法回顾性分析2018年5月至2020年7月在天津市第一中心医院和同济大学附属上海市第四人民医院就诊的,首次发作且发病时间在24 h内的39例急性缺血性卒中患者的临床和影像资料。对所有患者在入院时(基线)和接受卒中规范化治疗后2周内进行多模MR检查,包括扩散加权成像(DWI)、磁敏感加权成像(SWI)、动态磁敏感对比增强磁共振灌注成像(DSC-PWI)。在SWI上观察入院时不对称突出皮层静脉(APCV)的显示程度,并计算所有患者治疗前、后梗死侧APCV区的静脉血氧饱和度(SvO_(2))。将2次MR扫描获得的原始DWI和DSC-PWI图像导入软件,获得低灌注体积[达峰时间(Tmax)>6 s]和梗死核心体积(表观扩散系数值<620×10^(-6)mm^(2)/s)。根据基线梗死灶(DWI-ASPECT)评分及随访(FUP-ASPECT)评分的对比,将所有患者分为梗死进展组(27例)与梗死无进展组(12例)。采用两独立样本t检验或Mann-Whitney U检验比较2组间基线梗死核心体积、基线SvO_(2)、SvO_(2)变化值、基线低灌注区体积、低灌注区体积变化值的差异。采用单因素及多因素logistic回归分析,获得梗死进展的独立预测因子。采用Pearson相关分析评估SvO_(2)变化值、低灌注体积变化值与梗死变化评分的相关性。结果梗死进展组与梗死无进展组间基线梗死核心体积、基线SvO_(2)、低灌注区体积及低灌注区体积变化值差异均无统计学意义(P>0.05),梗死进展组与梗死无进展组SvO_(2)变化值差异有统计学意义[分别为(27±11)%和(35±6)%,t=-2.56,P=0.015]。单因素logistic回归分析显示SvO_(2)变化值是急性缺血性脑卒中梗死进展的影响因素(OR=0.872,95%CI 0.773~0.984,P=0.026);多因素logistic回归分析显示基线美国国立卫生研究院卒中量表评分(OR=1.248,95%CI 1.042~1.494,P=0.016)是预测急性缺血性脑卒中梗死进展的独立危险因素、SvO_(2)变化值(OR=0.814,95%CI 0.688~0.964,P=0.017)是独立保护因素。SvO_(2)变化值与梗死变化ASPECT评分呈正相关(r=0.425,P=0.007)。结论急性缺血性卒中血氧饱和度变化值能够独立预测急性缺血性脑卒中梗死的进展,治疗后血氧饱和度升高越多越有利于延缓梗死灶的进展。

Objective To explore the effect of dynamic changes of cerebral oxygen saturation before and after treatment on the progression of infarction in patients with acute ischemic stroke(AIS).Methods Totally 39 patients with first onset AIS within 24 hours in Tianjin First Central Hospital and Shanghai Fourth People′s Hospital Affiliated to Tongji University from May 2018 to July 2020 were enrolled retrospectively.All patients underwent multi-modal MR at admission(baseline)and within 2 weeks after standardized treatment,including diffusion weighted imaging(DWI),susceptibility weighted imaging(SWI),and dynamic magnetic sensitive contrast-enhanced magnetic resonance perfusion imaging(DSC-PWI).The degree of asymmetrically prominent cortical vein(APCV)at admission was observed on SWI,and the venous oxygen saturation(SvO_(2))of APCV on the infarcted cerebral hemisphere was calculated in all patients before and after treatment.The original DWI and DSC-PWI images obtained from two MR scans were imported into the software to obtain the delayed perfusion volume[peak time(Tmax)>6 s]and the infarct core volume(apparent diffusion coeffivient value<620×10^(-6)mm^(2)/s).According to the comparison of baseline infarct core(DWI-ASPECT)score and follow-up(FUP-ASPECT)score,all patients were divided into infarct progression group(27 cases)and non-infarct progression group(12 cases).Two independent sample t-test or Mann Whitney U-test were used to compare the differences of baseline infarct core volume,baseline SvO_(2),SvO_(2)change,baseline hypoperfusion volume and hypoperfusion volume change between the two groups.Univariate analysis and multivariate logistic regression analysis were used to obtain independent predictors of infarct progression.Pearson correlation analysis was used to evaluate the correlation between SvO_(2)change,hypoperfusion volume change and infarct change score respectively.Results Difference in baseline infarct core volume,baseline SvO_(2),hypoperfusion volume and hypoperfusion volume change between infarct progression group and non-progression group had no statistical significance(P>0.05).There was significant difference in the change of SvO_(2)between the infarct progression group and non-infarct progression group after treatment[(27±11)%,(35±6)%respectively,t=-2.56,P=0.015].Univariate logistic regression analysis showed that the change value of SvO_(2)was the influencing factor of infarction progression of AIS(OR=0.872,95%CI 0.773-0.984,P=0.026).Multivariate logistic regression analysis showed that the baseline NIHSS score(OR=1.248,95%CI 1.042-1.494,P=0.016)was an independent predictor of infarction progression in AIS,and the change value of SvO_(2)(OR=0.814,95%CI 0.688-0.964,P=0.017)was an independent protective factor.The change of SvO_(2)was positively correlated with the score of infarct change(r=0.425,P=0.007).Conclusions The change of SvO_(2)after AIS treatment can independently predict the progress of acute infarction.Improvement of SvO_(2)after treatment is conducive to delay the progress of infarction.