Li Guo-Yang, He Qiong, Jia Lin, He Ping, Luo Jianwen, Cao Yanping
Institute of Biomechanics and Medical Engineering, AML, Department of Engineering Mechanics, Tsinghua University, Beijing, China.
Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China.
Ultrasound Med Biol. 2017 Feb;43(2):505-516. doi: 10.1016/j.ultrasmedbio.2016.10.006. Epub 2016 Nov 28.
Many cardiovascular diseases can alter arterial stiffness; therefore, measurement of arterial wall stiffness can provide valuable information for both diagnosis of such diseases in the clinic and evaluation of the effectiveness of relevant drugs. However, quantitative assessment of the in vivo elastic properties of arterial walls in a non-invasive manner remains a great challenge. In this study, we found that the elastic modulus of the arterial wall can be extracted from the dispersion curve of the guided axial wave (GAW) measured using the ultrasound elastography method. It is shown that the GAW in the arterial wall can be well described with the Lamb wave (LW) model when the frequency exceeds a critical value f, whose explicit form is determined here based on dimensional analysis method and systematic finite-element simulations. Further, an inverse procedure is proposed to determine both f and the elastic modulus of the arterial wall. Phantom experiments have been performed to validate the inverse method and illustrate its potential use in the clinic.
许多心血管疾病会改变动脉僵硬度；因此，测量动脉壁僵硬度可为临床诊断此类疾病以及评估相关药物的疗效提供有价值的信息。然而，以非侵入性方式对动脉壁的体内弹性特性进行定量评估仍然是一项巨大挑战。在本研究中，我们发现动脉壁的弹性模量可从使用超声弹性成像方法测量的导波轴向波（GAW）的频散曲线中提取。结果表明，当频率超过临界值f时，动脉壁中的GAW可用兰姆波（LW）模型很好地描述，其显式形式在此基于量纲分析方法和系统的有限元模拟确定。此外，还提出了一种反演程序来确定f和动脉壁的弹性模量。已经进行了体模实验以验证该反演方法，并说明其在临床中的潜在用途。
