超声造影联合剪切波弹性成像对无症状颈动脉斑块患者缺血性脑卒中的预测价值

Predictive value of contrast-enhanced ultrasonography combined with shear wave elastography for risk of ischemic stroke in patients with asymptomatic carotid plaques

关键词:  缺血性脑卒中  颈动脉斑块  新生血管  弹性  超声

Key words:  ischemic stroke  carotid plaque  neovascularization  elasticity  ultrasound

摘要:

目的 探讨单独或联合应用超声造影（contrast-enhanced ultrasound, CEUS）与超声弹性成像（shear wave elastography, SWE），评估斑块内新生血管（intraplaque neovascularization, IPN）和斑块平均剪切波速（shear wave velocity, SWV）对无症状颈动脉斑块患者发生缺血性脑卒中的预测价值。 方法 回顾性选取接受颈动脉斑块CEUS和SWE的无症状颈动脉斑块患者，对所有患者随访180 d。根据随访期间是否发生缺血性脑卒中，将患者分为脑卒中组和非脑卒中组。使用Cox比例风险回归模型确定缺血性脑卒中的独立预测因素，使用Kaplan-Meier生存曲线评估累计发病率。建立列线图并绘制受试者工作特征（receiver operating characteristic, ROC）曲线分析各指标预测缺血性脑卒中的价值。 结果 共纳入90例患者，根据随访期间是否发生脑卒中分为脑卒中组（8例），和非脑卒中组（82例）。IPN分级2级组和较小SWV组的脑卒中发生率显著高于IPN分级0-1级组和较大SWV组（P<0.001和P=0.025）。多因素Cox回归显示，IPN和SWV是颈动脉斑块患者未来缺血性脑卒中事件的独立预测因子（P=0.045,P=0.028）。基于IPN和SWV建立的列线图对患者缺血性脑卒中风险具有良好的预测能力（C-index=0.898）。ROC曲线分析结果显示，列线图预测患者缺血性脑卒中事件的AUC值最高（0.897），并以截断值将患者分为高危组和低危组，高危组的缺血性脑卒中发生率显著高于低危组（P<0.001）。 结论 IPN联合SWV能够有效预测无症状颈动脉斑块患者的缺血性脑卒中事件，为卒中的早期防治提供重要依据。

Abstract:

Objective To investigate the predictive value of contrast-enhanced ultrasonography(CEUS), combined with shear wave elastography(SWE) for risk of ischemic stroke in patients with asymptomatic carotid plaques. Methods Clinical and imaging data of 90 patients with carotid plaques who underwent CEUS and SWE examinations were retrospectively analyzed. Patients were followed up for 180 d. Ischemic stroke occurred in 8 cases(stroke group), did not occur in 82 cases(non-stroke group). Univariate and multivariate Cox regression were used to analyze the predictors of ischemic stroke events, and a nomogram was developed based on above risk factors to predict the incidence of stroke. Cumulative incidence was evaluated using the Kaplan-Meier survival analysis. Receiver operating characteristic(ROC) curve was generated to analyze the value of each index in assessing the risk of ischemic stroke. Results The risk of ischemic stroke in patients with grade 2 intraplaque neovascularization(IPN) and lower shear wave velocity(SWV) was higher than those with grade 0-1 IPN and higher SWV(P<0.001, P=0025). Multivariate Cox regression showed that IPN and SWV were independent risk factors for predicting ischemic stroke in carotid plaque patients(P=0.045, P=0.028). The nomogram developed based on IPN and SWV had good discrimination effect(C-index=0.898). ROC curve showed that the AUC of the nomogram for predicting risk of ischemia strok was 0.897. According to the cutoff value, patients were divided into low-risk group and high-risk group, the risk of ischemic stroke in high-risk group was higher than that in low-risk group(P<0.001). Conclusion The combination of IPN and SWV demonstrates good predictive value for the risk of ischemic stroke in asymptomatic patients with carotid plaques.