Department of Robotics and Mechatronics, AGH University of Science and Technology, 30-059 Krakow, Poland.
Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA; Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN 55905, USA.
Ultrasonics. 2021 Jan;109:106257. doi: 10.1016/j.ultras.2020.106257. Epub 2020 Sep 21.
Ultrasound shear wave elastography is a modality used for noninvasive, quantitative evaluation of soft tissue mechanical properties. A common way of exploring the tissue viscoelasticity is through analyzing the shear wave velocity dispersion curves. The variation of phase velocity with frequency or wavelength is called the dispersion curve. An increase of the available spectrum to be used for phase velocity estimation is meaningful for a tissue dispersion analysis in vivo. A number of available methods for dispersion relation estimation exist which can give diffuse results due the presence of noise in the measured data. In this work we compare six selected methods used for dispersion curve calculation in viscoelastic materials. Non-parametric, parametric and high-resolution methods were examined and compared. We tested selected methods on digital phantom data created using finite-difference-based method in tissue-mimicking viscoelastic media as well as on the experimental custom tissue-mimicking phantoms. In addition, we evaluated the algorithms with different levels of added white Gaussian noise to the shear wave particle velocity from numerical phantoms. Tests conducted showed that more advanced methods can offer better frequency resolution, and less variance than the fast Fourier transform. In addition, the non-parametric Blackman-Tukey approach exhibits similar performance and can be interchangeably used for shear wave phase velocity dispersion curves calculation.
超声剪切波弹性成像是一种用于无创、定量评估软组织力学特性的方法。一种常用的研究组织粘弹性的方法是通过分析剪切波速度频散曲线。相速度随频率或波长的变化称为频散曲线。增加可用于相速度估计的可用频谱对于体内组织弥散分析是有意义的。存在噪声的情况下，有许多可用的方法可以用于估计频散关系，这些方法的结果可能会比较分散。在这项工作中，我们比较了六种用于粘弹性材料的频散曲线计算的选定方法。我们检查并比较了非参数、参数和高分辨率方法。我们在基于有限差分的方法在组织模拟粘弹性介质中创建的数字体模数据以及在实验定制体模上测试了选定的方法。此外，我们还评估了不同水平的高斯白噪声添加到数值体模中的剪切波质点速度的算法。进行的测试表明，更先进的方法可以提供更好的频率分辨率，并且比快速傅里叶变换的方差更小。此外，非参数的 Blackman-Tukey 方法表现出类似的性能，并且可以互换用于剪切波相速度频散曲线的计算。
