A Lattice Boltzmann method model of diffusion-weighted magnetic resonance imaging in skeletal muscle

Aging and obesity is associated with reduction in muscle mass and increase in fat mass, leading to decline in both physical function and health. Probing the cellular microstructure of skeletal muscle with noninvasive methods is paramount in developing effective therapeutic procedures for the elderly, such as physical exercise. Using special proton magnetic resonance imaging (MRI) protocols we can investigate non-invasively diffusion phenomena within skeletal muscle. This project focuses on the numerical study of the effect of microstructure on the effective diffusion coefficient via a Lattice Boltzmann model (LBM). Specifically, we aim to characterize how variations in microstructure and mass transport properties affect the local apparent diffusion coefficient of water measured with Diffusion Tensor Imaging (DTI). A numerical model is developed to solve the Bloch-Torrey equation in a periodic domain containing muscle cells surrounded by permeable membranes. This model is shown to be convergent in both time and space at the theoretical truncation error rate and to agree with analytical solutions of limiting cases. The effect of membrane permeability is investigated and found to be consistent in trend with prior experimental investigations. A simpler two-compartment exchange model is also investigated and compared with the LBM model. It is found that qualitative agreement exists in terms of variations in ellipticity and permeability, however, there is qualitative disagreement in the model for changes in cell volume fraction. This disagreement is investigated systematically and the numerical source of the disagreement between the two models is identified. Our results demonstrate that the continuum LBM model is superior to the two-compartmental model for human muscle MRI.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Naughton, Noel M.

Contributors dc:contributor

• Georgiadis, John G.

• Lattice Boltzmann Method
• Magnetic resonance imaging (MRI)
• Diffusion tensor imaging (DTI)
• Diffusion-Weighted Imaging
• myocyte
• diffusion
• skeletal muscle

Statement dc:rights

• Copyright 2016 Noel Naughton

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/90966

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/90966