基于超声剪切波频散成像探讨颈动脉黏弹性与血流动力学的相关性

Correlation between carotid viscoelasticity and hemodynamics based on ultrasound shear wave dispersion imaging

目的应用超声剪切波频散(USWD)技术检测颈动脉黏弹性,探讨其与血流动力学的相关性。方法招募既往无心脑血管事件病史志愿者45例,依据年龄中位数分为高年龄组(≥50岁,n=23)和低年龄组(<50岁,n=22)。采用USWD技术检测受试者颈总动脉,获取颈总动脉剪切波弹性指标动脉壁剪切波弹性模量(SWER)值和剪切波黏性指标动脉壁剪切波频散(SWDR)值;用多普勒超声获取颈总动脉血流动力学参数[速度时间积分(VTI)、收缩期峰值流速(PSV)、舒张末期流速(EDV)和平均流速(MFV)]。采用Pearson相关分析分析SWER和SWDR与血流动力学参数的关系。结果与低年龄组比较,高年龄组受试者颈总动脉SWER和SWDR均减小(P均<0.05)。高年龄组受试者颈总动脉VTI、PSV、EDV和MFV均小于低年龄组(P<0.05,P<0.01)。颈总动脉剪切波弹性指标SWER与血流动力学参数VTI、PSV、EDV和MFV呈正相关(r=0.354、0.400、0.467和0.310;P<0.01,P<0.05);剪切波黏性指标SWDR与VTI和PSV呈负相关,而与MFV呈正相关(r=-0.481、-0.522和0.352,P均<0.01)。结论 USWD技术可鉴别颈动脉黏弹性指标的变化,这种变化与血流动力学改变有关。

Objective To measure the carotid viscoelasticity using ultrasound shear wave dispersion(USWD), and to explore the correlation between the viscoelasticity and hemodynamics. Methods Forty-five volunteers without history of cardiovascular and cerebrovascular events were recruited and divided into elder group(≥50 years old, n=23) and younger group(<50 years old, n=22) according to the median age. The common carotid arteries were detected by USWD, and SWER(elastic index) and SWDR(viscous index) were obtained. Hemodynamic parameters, including velocity time integral(VTI), peak systolic velocity(PSV), end-diastolic velocity(EDV), and mean flow velocity(MFV), were measured using Doppler ultrasound. Correlations between SWER, SWDR and hemodynamic parameters were analyzed using Pearson analysis. Results The SWER, SWDR, VTI, PSV, EDV and MFV in the elder group were significantly lower than those in the younger group(P<0.05, P<0.01). The SWER was positively correlated with VTI, PSV, EDV and MFV(r=0.354, 0.400, 0.467 and 0.310;P<0.01, P<0.05). The SWDR was negatively correlated with VTI and PSV(r=-0.481 and-0.522, both P<0.01), but positively correlated with MFV(r=0.352, P<0.01). Conclusion USWD may identify the change of carotid viscoelasticity, and the change of viscoelasticity is related to hemodynamics.