Roy Tuhin, Konofagou Elisa E
Dept. of Biomedical Engineering, Columbia University, New York City, USA.
Dept. of Biomedical Engineering, Columbia University, New York City, USA; Dept. of Radiology (Physics), and Dept. of Neurological Surgery, Columbia University, New York City, USA.
J Biomech. 2025 Sep;190:112886. doi: 10.1016/j.jbiomech.2025.112886. Epub 2025 Jul 30.
Towards the characterization of viscoelasticity of the soft tissue, which is an important biomarker, this study aims to investigate the effectiveness of the Harmonic Shear Wave Elastography (HSWE) framework by analyzing the frequency-dependent phase velocity maps, using a 3D Finite-Element-based simulation framework. Here, we developed and verified a 3D finite-element framework to accurately model the tissue displacement under a multi-frequency HSWE setting. The HSWE results were compared using both simulation and phantom experiments against those from the Pulsed Shear Wave Elastography (PSWE) method which is widely used in shear wave elastography problems. Particularly, we analyzed the group and frequency-dependent phase velocities, focusing on the frequency range of 300 to 800 Hz. Additionally, we conducted parametric studies to examine the effects of inclusion size, stiffness, and viscosity. The HSWE framework provided accurate measurements of group and phase velocities, comparable to those obtained using the PSWE method. The median differences between HSWE and PSWE results were 5.21 % and 9.14 % for group and phase velocities, respectively, in simulations, and 13.98 % and 22.32 % for group and phase velocities, respectively, in phantom experiments. Parametric studies showed that the HSWE framework is effective in accurately characterizing the location, size, stiffness and viscoelastic properties of tissue inclusions, with notable improvements over PSWE, particularly for smaller inclusions at lower frequencies. Future work will focus on optimizing the HSWE framework for clinical use and developing inverse models to estimate the underlying viscoelastic shear moduli of the tissue to enhance its diagnostic capabilities.
作为一种重要的生物标志物，软组织的粘弹性表征是本研究的目标，该研究旨在通过使用基于三维有限元的模拟框架分析频率相关的相速度图，来探究谐波剪切波弹性成像（HSWE）框架的有效性。在此，我们开发并验证了一个三维有限元框架，以精确模拟多频HSWE设置下的组织位移。使用模拟和体模实验将HSWE结果与广泛应用于剪切波弹性成像问题的脉冲剪切波弹性成像（PSWE）方法的结果进行比较。特别地，我们分析了群速度和频率相关的相速度，重点关注300至800Hz的频率范围。此外，我们进行了参数研究，以检验内含物大小、刚度和粘度的影响。HSWE框架提供了与PSWE方法相当的群速度和相速度的精确测量值。在模拟中，HSWE和PSWE结果在群速度和相速度方面的中位数差异分别为5.21%和9.14%，在体模实验中，群速度和相速度方面的中位数差异分别为13.98%和22.32%。参数研究表明，HSWE框架在准确表征组织内含物的位置、大小、刚度和粘弹性特性方面是有效的，与PSWE相比有显著改进，特别是对于低频下较小的内含物。未来的工作将集中于优化HSWE框架以供临床使用，并开发反演模型来估计组织的潜在粘弹性剪切模量，以增强其诊断能力。
