Wide Frequency Range Shear Modulus Dispersion of Soft Tissue Samples Measured by Magnetic Resonance Elastography

Dieter Klatt¹, Kerstin Riek², Hassan Nuzha¹, Susanne Mller³, Ingolf Sack¹, Jrgen Braun²

Magnetic resonance elastography (MRE) reveals information about biomechanical properties related to mechanical connectivity and micromechanical order in tissue. To develop MRE towards an in vivo rheometry technique an extension of the range of mechanical excitation and a modelling of tissue properties is mandatory. Therefore wide-range modulus-dispersion MRE is introduced and applied to biological tissue samples. A powerlaw simplification was used to model the dispersion function of the complex shear modulus. In this context, brain and liver tissue show very similar viscoelastic properties, while fibrotic liver displays distinctly higher shear modulus values, similar to the anisotropic elastic constants of excised muscle.