Poroelasticity as a Model of Soft Tissue Structure: Hydraulic Permeability Reconstruction for Magnetic Resonance Elastography in Silico

Frontiers in Physics

Scott Gordon-Wylie¹  Damian R. Sowinski¹  Matthew D. J. McGarry¹  John B Weaver²  Keith D. Paulsen²  Elijah E. W. Van Houten³ 

[1] Hanover, NH, United States;Hanover, NH, United States;Hanover, NH, United States;Lebanon, NH, United States;Sherbrooke, QC, Canada;

关键词: Elastography;    MRI;    Biophysics;    Biomechanics;    Bayesian Inference;    Effective Field Theory;    Continuum Mechanics;    Porous Materials;   

DOI  :  10.3389/fphy.2020.617582

来源: Frontiers

【 摘 要 】

Magnetic Resonance Elastography allows noninvasive visualization of tissue mechanical properties by measuring the displacements resulting from applied stresses, and fitting a mechanical model. Poroelasticity naturally lends itself to describing tissue - a biphasic medium, consisting of both solid and fluid components. This article reviews the theory of poroelasticity, and shows that the spatial distribution of hydraulic permeability, the ease with which the solid matrix permits the flow of fluid under a pressure gradient, can be faithfully reconstructed without spatial priors in simulated environments. The paper describes an in-house MRE computational platform - a multi-mesh, finite element poroelastic solver coupled to an artificial epistemic agent capable of running Bayesian inference to reconstruct inhomogenous model mechanical property images from measured displacement fields. Building on prior work, the domain of convergence for inference is explored, showing that hydraulic permeabilities over several orders of magnitude can be reconstructed given very little prior knowledge of the true spatial distribution.

【 授权许可】

CC BY