Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models

Traumatic brain injury (TBI) is a major public health challenge. Up to 90 % of TBIs are on the mild spectrum of TBI (mTBI), where diagnosis is a major challenge. Majority of studies in this field have been conducted on human subjects, which inherently suffer from the lack of appropriate control grou...

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Main Authors: Maryam Tayebi, Eryn Kwon, Alan Wang, Justin Fernandez, Samantha Holdsworth, Vickie Shim
Format: Article
Language:English
Published: Elsevier 2024-06-01
Series:Brain Multiphysics
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666522023000266
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author Maryam Tayebi
Eryn Kwon
Alan Wang
Justin Fernandez
Samantha Holdsworth
Vickie Shim
author_facet Maryam Tayebi
Eryn Kwon
Alan Wang
Justin Fernandez
Samantha Holdsworth
Vickie Shim
author_sort Maryam Tayebi
collection DOAJ
description Traumatic brain injury (TBI) is a major public health challenge. Up to 90 % of TBIs are on the mild spectrum of TBI (mTBI), where diagnosis is a major challenge. Majority of studies in this field have been conducted on human subjects, which inherently suffer from the lack of appropriate control group, selection bias, and individual differences in patients. To overcome these limitations, animal studies have been used as an alternative approach to provide deeper insights into the underlying mechanism related to the injury. Therefore our aim is to investigate various quantitative imaging biomarkers acquired from T1-W and diffusion tensor imaging (DTI) sequences to provide more information about the microstructural changes in the brain after mTBI. We then use this to generate subject-specific finite element models of the brain and examine how the changes in the brain material properties reflected in MR images affects strain distribution patterns on a subsequent head hit. Our study revealed a decrease in FA and an increase in diffusivity indices (MD, AD, RD) in the white matter tracts of the brain. This finding may represent the axonal damage, demyelination and gliosis after mild TBI, which have been shown in other animal and human studies. Moreover, our FE analysis showed that microstructural changes in the brain after mTBI might have weakened the structural integrity of the brain as the subsequent head hit led to wider and more severe brain deformations. Significance: Animal models have been used to investigate biomechanical and pathophysiological aspects of mild traumatic brain injuries in the past. Still, most of them used small animals such as rats and mice. These models provided valuable insight into the pathophysiology of mTBI, but their findings have limitations due to their inherent differences to human brains. We have developed a large animal model of mTBI with sheep brains by combining advanced MRI and finite element analysis as they mimic the human brain better. To the best of our knowledge, this study is the first mTBI neuroimaging study conducted on large animal brains to investigate the diffusional changes in the white matter tracts after mTBI. Our FE analysis revealed that such microstructural changes resulted in tissue softening as the extent of brain deformation increased on a subsequent head hit, indicating increased brain vulnerability after head impacts.
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spelling doaj.art-5c89ae653cef4d999fb49241d9ab3b262023-12-28T05:19:54ZengElsevierBrain Multiphysics2666-52202024-06-016100088Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE modelsMaryam Tayebi0Eryn Kwon1Alan Wang2Justin Fernandez3Samantha Holdsworth4Vickie Shim5Auckland Bioengineering Institute, University of Auckland, Auckland, New ZealandAuckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New ZealandAuckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New ZealandAuckland Bioengineering Institute, University of Auckland, Auckland, New ZealandCentre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Department of Anatomy and Medical Imaging, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New ZealandAuckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Corresponding author.Traumatic brain injury (TBI) is a major public health challenge. Up to 90 % of TBIs are on the mild spectrum of TBI (mTBI), where diagnosis is a major challenge. Majority of studies in this field have been conducted on human subjects, which inherently suffer from the lack of appropriate control group, selection bias, and individual differences in patients. To overcome these limitations, animal studies have been used as an alternative approach to provide deeper insights into the underlying mechanism related to the injury. Therefore our aim is to investigate various quantitative imaging biomarkers acquired from T1-W and diffusion tensor imaging (DTI) sequences to provide more information about the microstructural changes in the brain after mTBI. We then use this to generate subject-specific finite element models of the brain and examine how the changes in the brain material properties reflected in MR images affects strain distribution patterns on a subsequent head hit. Our study revealed a decrease in FA and an increase in diffusivity indices (MD, AD, RD) in the white matter tracts of the brain. This finding may represent the axonal damage, demyelination and gliosis after mild TBI, which have been shown in other animal and human studies. Moreover, our FE analysis showed that microstructural changes in the brain after mTBI might have weakened the structural integrity of the brain as the subsequent head hit led to wider and more severe brain deformations. Significance: Animal models have been used to investigate biomechanical and pathophysiological aspects of mild traumatic brain injuries in the past. Still, most of them used small animals such as rats and mice. These models provided valuable insight into the pathophysiology of mTBI, but their findings have limitations due to their inherent differences to human brains. We have developed a large animal model of mTBI with sheep brains by combining advanced MRI and finite element analysis as they mimic the human brain better. To the best of our knowledge, this study is the first mTBI neuroimaging study conducted on large animal brains to investigate the diffusional changes in the white matter tracts after mTBI. Our FE analysis revealed that such microstructural changes resulted in tissue softening as the extent of brain deformation increased on a subsequent head hit, indicating increased brain vulnerability after head impacts.http://www.sciencedirect.com/science/article/pii/S2666522023000266Mild traumatic brain injuryDiffusion tensor imagingFinite element analysisLarge animal model
spellingShingle Maryam Tayebi
Eryn Kwon
Alan Wang
Justin Fernandez
Samantha Holdsworth
Vickie Shim
Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
Brain Multiphysics
Mild traumatic brain injury
Diffusion tensor imaging
Finite element analysis
Large animal model
title Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
title_full Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
title_fullStr Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
title_full_unstemmed Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
title_short Analysis of the pattern of microstructural changes in the brain after mTBI with diffusion tensor imaging and subject-specific FE models
title_sort analysis of the pattern of microstructural changes in the brain after mtbi with diffusion tensor imaging and subject specific fe models
topic Mild traumatic brain injury
Diffusion tensor imaging
Finite element analysis
Large animal model
url http://www.sciencedirect.com/science/article/pii/S2666522023000266
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