Adikary Shuvrodeb, Urban Matthew W, Guddati Murthy N
North Carolina State University, Raleigh, NC, US.
Mayo Clinic, Rochester, MN, USA.
ArXiv. 2024 Nov 18:arXiv:2411.11572v1.
Tissue viscoelasticity is becoming an increasingly useful biomarker beyond elasticity and can theoretically be estimated using shear wave elastography (SWE), by inverting the propagation and attenuation characteristics of shear waves. Estimating viscosity is often more difficult than elasticity because attenuation, the main effect of viscosity, leads to poor signal-to-noise ratio of the shear wave motion. In the present work, we provide an alternative to existing methods of viscoelasticity estimation that is robust against noise. The method minimizes the difference between simulated and measured versions of two sets of peaks (twin peaks) in the frequency-wavenumber domain, obtained first by traversing through each frequency and then by traversing through each wavenumber. The slopes and deviation of the twin peaks are sensitive to elasticity and viscosity respectively, leading to the effectiveness of the proposed inversion algorithm for characterizing mechanical properties. This expected effectiveness is confirmed through verification, followed by validation and application, indicating that the proposed approach can be effectively used in accurately estimating viscoelasticity, thus potentially contributing to the development of enhanced biomarkers.
组织粘弹性正成为一种超越弹性的越来越有用的生物标志物，理论上可以通过剪切波弹性成像（SWE），通过反转剪切波的传播和衰减特性来估计。估计粘度通常比估计弹性更困难，因为衰减是粘度的主要影响，会导致剪切波运动的信噪比很差。在本研究中，我们提供了一种对现有粘弹性估计方法的替代方法，该方法对噪声具有鲁棒性。该方法最小化了在频率-波数域中两组峰值（双峰）的模拟版本和测量版本之间的差异，首先通过遍历每个频率，然后通过遍历每个波数获得。双峰的斜率和偏差分别对弹性和粘度敏感，从而导致所提出的反演算法在表征力学性能方面的有效性。通过验证、随后的确认和应用证实了这种预期的有效性，表明所提出的方法可以有效地用于准确估计粘弹性，从而可能有助于开发增强型生物标志物。
