Explicit Modeling of White Matter Axonal Fiber Tracts in a Finite Element Brain Model

  • Taotao Wu
  • Ahmed Alshareef
  • J. Sebastian Giudice
  • Matthew B. PanzerEmail author
State-of-the-Art Modeling and Simulation of the Brain's Response to Mechanical Loads


Many human brain finite element (FE) models lack mesoscopic (~ 1 mm) white matter structures, which may limit their capability in predicting TBI and assessing tissue-based injury metrics such as axonal strain. This study investigated an embedded method to explicitly incorporate white matter axonal fibers into an existing 50th percentile male brain model. The white matter was decomposed into myelinated axon tracts and an isotropic ground substance that had similar material properties to gray matter. The axon tract bundles were derived from a population-based tractography template explicitly modeled using 1-D cable elements. The axonal fibers and ground substance material were implemented using hyper-viscoelastic constitutive models, which were calibrated using white and gray matter brain tissue material testing data available in the literature. Finally, the new axon-based model was extensively validated for brain-skull relative deformation under various loading conditions (n = 17) and showed good biofidelity compared to other brain models. Through these analyses, we demonstrated the applicability of this method for incorporating axonal fiber tracts into an existing FE brain model. The axon-based model will be a useful tool for understanding the mechanisms of TBI, evaluating tissue-based injury metrics, and developing injury mitigation systems.


Traumatic brain injury Axonal fibers Brain model Finite element model validation 



Diffusion MRI data were provided in part by the Human Connectome Project, WU-Minn Consortium (Principal Investigators: David Van Essen and Kamil Ugurbil; 1U54MH091657) funded by the 16 NIH Institutes and Centers that support the NIH Blueprint for Neuroscience Research; and by the McDonnell Center for Systems Neuroscience at Washington University. The research presented in this paper was made possible in part by a grant from Football Research, Inc. (FRI). The views expressed are solely those of the authors and do not represent those of FRI or any of its affiliates or funding sources.

Conflict of interest

No competing financial interests exist.

Supplementary material

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Supplementary material 1 (DOCX 3752 kb)


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Copyright information

© Biomedical Engineering Society 2019

Authors and Affiliations

  • Taotao Wu
    • 1
  • Ahmed Alshareef
    • 1
  • J. Sebastian Giudice
    • 1
  • Matthew B. Panzer
    • 1
    Email author
  1. 1.Center for Applied BiomechanicsUniversity of VirginiaCharlottesvilleUSA

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