Explicit Modeling of White Matter Axonal Fiber Tracts in a Finite Element Brain Model
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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.
KeywordsTraumatic 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.
- 2.Arbogast, K. B., and S. S. Margulies. Regional differences in mechanical properties of the porcine central nervous system. SAE Technical Paper, 1997.Google Scholar
- 6.Brands, D. W., P. H. Bovendeerd, G. W. Peters, J. S. Wismans, M. H. Paas, and J. L. van Bree. Comparison of the dynamic behavior of brain tissue and two model materials. SAE Technical Paper, 1999.Google Scholar
- 10.Centers for Disease Control and Prevention. Report to congress on traumatic brain injury in the United States: epidemiology and rehabilitation, 2015.Google Scholar
- 14.Davis, M. L., B. Koya, J. M. Schap, and F. S. Gayzik. Development and full body validation of a 5th percentile female finite element model. SAE Technical Paper, 2016.Google Scholar
- 17.Fung, Y. Biomechanics: mechanical properties of living tissues. Berlin: Springer Science & Business Media, 2013.Google Scholar
- 25.Gehre, C., H. Gades, and P. Wernicke. Objective rating of signals using test and simulation responses. Washington, DC: National Highway Traffic Safety Administration, 2009.Google Scholar
- 26.Gennarelli, T. A., L. Thibault, and A. K. Ommaya. Pathophysiologic responses to rotational and translational accelerations of the head. SAE Technical Paper, 1972.Google Scholar
- 27.Giordano, C., and S. Kleiven. Evaluation of axonal strain as a predictor for mild traumatic brain injuries using finite element modeling. SAE Technical Paper, 2014.Google Scholar
- 30.Golman, A., A. Wickwire, T. Harrigan, A. Iwaskiw, R. Armiger, and A. Merkle. Hierarchical model validation of the falx cerebri and tentorium cerebelli. In: Proceedings of the forty first international workshop (2013).Google Scholar
- 32.Hardy, W. N., C. D. Foster, M. J. Mason, K. H. Yang, A. I. King, and S. Tashman. Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. SAE Technical Paper, 2001.Google Scholar
- 36.Jin, X., J. B. Lee, L. Y. Leung, L. Zhang, K. H. Yang, and A. I. King. Biomechanical Response of the Bovine Pia-Arachnoid Complex to Tensile Loading at Varying Strain Rates. SAE Technical Paper, 2006.Google Scholar
- 47.Nicolle, S., M. Lounis, and R. Willinger. Shear properties of brain tissue over a frequency range relevant for automotive impact situations: new experimental results. SAE Technical Paper, 2004.Google Scholar
- 60.Takhounts, E.G., S.A. Ridella, V. Hasija, R.E. Tannous, J.Q. Campbell, D. Malone, K. Danelson, J.Stitzel, S. Rowson, and S. Duma. Investigation of traumatic brain injuries using the next generation of simulated injury monitor (SIMon) finite element head model. SAE Technical Paper, 2008.Google Scholar