Annu Int Conf IEEE Eng Med Biol Soc. 2021 Nov;2021:3877-3881. doi: 10.1109/EMBC46164.2021.9630470.
Reverberant shear wave elastography (RSWE) has become a promising approach to quantifying soft tissues' viscoelastic properties by the propagating shear wave speed (SWS) estimation based on the particle velocity autocorrelation. In this work, three different practical settings were evaluated for the SWS estimation by numerical simulations of an isotropic, homogenous, and elastic medium: first, the 2D representation of the particle velocity, second, the spatial autocorrelation computation, and third, the selection of the curve fitting domain. We conclude that the 2D autocorrelation function using the Wiener-Khinchin theorem provides up to 127 times faster results than traditional autocorrelation methods. Additionally, we state that extracting the magnitude and phase from the Fourier transform of the temporal domain, applying the 2D-autocorrelation on a mobile square window sized at least two wavelengths, and fitting the monotonically decreasing part of the autocorrelation profile's central lobe results in more accurate (13.2% of bias) and precise (5.3% of CV) estimations than other practical settings.Clinical relevance- Affections in soft tissues' biomechanical properties are related to pathologies, such as tumor cancer, muscular degenerative diseases, or fibrosis. These changes are quantified by the SWS and its derived viscoelastic parameters. RSWE is a promising approach for their characterization. In this work, we evaluated alternative elections of practical settings within the methodology. Numerical simulations indicate they lead to faster and more reliable local SWS estimations than conventional settings.
背向剪切波弹性成像（RSWE）已成为一种很有前途的方法，可以通过基于粒子速度自相关的传播剪切波速度（SWS）估计来量化软组织的粘弹性特性。在这项工作中，通过对各向同性、均匀和弹性介质的数值模拟，评估了 SWS 估计的三种不同实际设置：首先是粒子速度的 2D 表示，其次是空间自相关计算，最后是曲线拟合域的选择。我们得出结论，使用维纳-辛钦定理的 2D 自相关函数提供的结果比传统自相关方法快高达 127 倍。此外，我们还指出，从时域的傅里叶变换中提取幅度和相位，在至少两个波长大小的移动正方形窗口上应用 2D 自相关，并拟合自相关轮廓中央叶的单调下降部分，会得到更准确（13.2%的偏差）和精确（5.3%的 CV）的估计值，优于其他实际设置。临床相关性-软组织生物力学特性的变化与肿瘤癌症、肌肉退行性疾病或纤维化等疾病有关。这些变化通过 SWS 及其衍生的粘弹性参数来量化。RSWE 是对其特征进行描述的一种很有前途的方法。在这项工作中，我们评估了该方法中实际设置的替代选择。数值模拟表明，它们比传统设置可以更快、更可靠地进行局部 SWS 估计。
