Department of Biological Sciences and Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India.
Department of Chemical Engineering, Indian Institute of Technology Gandhinagar, Gandhinagar, Gujarat 382355, India.
J Acoust Soc Am. 2024 Mar 1;155(3):2025-2036. doi: 10.1121/10.0025291.
Quantitative, accurate, and standardized metrics are important for reliable shear wave elastography (SWE)-based biomarkers. For over two decades, the linear-elastic material assumption has been employed in SWE modes. In recent years, viscoelasticity estimation methods have been adopted in a few clinical systems. The current study aims to systematically quantify differences in SWE estimates obtained using linear-elastic and viscoelastic material assumptions. An acousto-mechanical simulation framework of acoustic radiation force impulse-based SWE was created to elucidate the effect of material viscosity and shear modulus on SWE estimates. Shear modulus estimates exhibited errors up to 72% when a numerical viscoelastic phantom was assessed as linearly elastic. Shear modulus estimates of polyvinyl alcohol phantoms between rheometry and SWE following the Kelvin-Voigt viscoelastic model assumptions were not significantly different. However, the percentage difference in shear modulus estimates between rheometry and SWE using the linear-elastic assumption was 50.1%-62.1%. In ex vivo liver, the percentage difference in shear modulus estimates between linear-elastic and viscoelastic methods was 76.1%. These findings provide a direct and systematic quantification of the potential error introduced when viscoelastic tissues are imaged with SWE following the linear-elastic assumption. This work emphasizes the need to utilize viscoelasticity estimation methods for developing robust quantitative imaging biomarkers.
定量、准确和标准化的指标对于基于剪切波弹性成像（SWE）的可靠生物标志物至关重要。二十多年来，线性弹性材料假设一直被应用于 SWE 模式中。近年来，一些临床系统已经采用了粘弹性估计方法。本研究旨在系统地量化使用线性弹性和粘弹性材料假设获得的 SWE 估计之间的差异。创建了一个基于声辐射力脉冲的 SWE 的声力学模拟框架，以阐明材料粘度和剪切模量对 SWE 估计的影响。当将数值粘弹性体模体评估为线性弹性时，剪切模量估计会出现高达 72%的误差。根据 Kelvin-Voigt 粘弹性模型假设，流变仪和 SWE 之间的聚乙烯醇（PVA）体模的剪切模量估计值没有显著差异。然而，使用线性弹性假设时，流变仪和 SWE 之间的剪切模量估计值之间的差异百分比为 50.1%-62.1%。在离体肝脏中，线性弹性和粘弹性方法之间的剪切模量估计值差异百分比为 76.1%。这些发现提供了一种直接和系统的方法，量化了当粘弹性组织按照线性弹性假设进行 SWE 成像时引入的潜在误差。这项工作强调了需要使用粘弹性估计方法来开发稳健的定量成像生物标志物。
