Estimation of isotropic and anisotropic biomechanical properties of the lower leg muscle during muscle contraction using DTI and MR elastography

In this study, DTI and multifrequency MR elastography (MRE) were applied to 6 subjects to investigate the changes of fiber orientation and the biomechanical properties of the lower leg muscle during passive plantarflexion and dorsiflexion. Using the pentation angle estimated from DTI, MRE data were processed to obtain both isotropic shear wave speed (c) and anisotropic shear moduli (μ12, μ13) as well as Young’s modulus (E3). Preliminary findings showed significant changes of the biophysical properties upon lower leg muscle contraction.