Motivation: The anisotropic mechanical properties of fiber-embedded biological tissues are crucial for understanding development, aging, disease progression, and treatment response. Goal(s): Measure mechanical anisotropy in vivo using elastography in a fast and accurate way. Approach: A computational framework using the traveling wave expansion model that exploits the wave characteristics of transversely isotropic materials was proposed. Results: Simulations, ex vivo muscle tissue, and in vivo human brain experiments validate the performance of the proposed method in measuring the anisotropic biomechanical properties, showing its potential for assessing fiber-embedded tissues. Impact: The TWE-NITI method offers an accurate and fast way to measure fiber-reinforced tissues in vivo, showing the potential application of anisotropic MRE. Furthermore, the proposed framework may also help solving the inverse problem in other fields.
Ma et al. (2025) studied this question.