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SUMMARY:MRI-based Modelling of Traumatic Brain Injury - Martin Ostoja-Star
 zewski (University of Illinois at Urbana-Champaign)
DTSTART:20230725T140000Z
DTEND:20230725T150000Z
UID:TALK203557@talks.cam.ac.uk
DESCRIPTION:A high-resolution MRI-based finite element (FE) model is used 
 as a basis for study of transient wave dynamics during blunt head trauma (
 BHT). Traditional numerical models employ homogenized\, or averaged\, mech
 anical properties to approximate constitutive relations of biological tiss
 ues [1]. In this work\, we extend our model\, previously presented\, and v
 alidated in [2-4]\, by introducing thermoelastic effects [5]. The model is
  based on T1- and T2-weighted structural magnetic resonance imaging (MRI) 
 dataset of a specific subject. Image voxels are directly converted to eigh
 t-node hexahedral finite elements\, roughly of side 1.30 mm. Individual el
 ements are assigned tissue types &ndash\; skull\, cerebrospinal fluid (CSF
 )\, grey matter\, and white matter &ndash\; based on image segmentation re
 sults. Material properties of the white matter are captured through MRE us
 ing a nonlinear inversion technique developed in [6]. Using a viscoelastic
  material model\, the storage and loss moduli are reconstructed at the sam
 e spatial resolution as the finite elements. All other tissues in our mode
 l are assumed to be heterogeneous and isotropic with values chosen from li
 terature. The very fine mesh used in our model enables simulations of tran
 sient wavefronts being only several millimetres in thickness. Loading is i
 n the form of an impact pulse\, taken from [7]. The model reported here is
  based on a coupled thermoelasticity under infinitesimal strain and either
  Fourier or Maxwell-Cattaneo heat conduction assumptions. It is found that
  mechanical impacts on the forehead cause a temperature rise of up to 0.3 
 C above the reference homogeneous temperature field.\n&nbsp\;\nREFERENCES:
 &nbsp\; \n\nMadhukar\, A. and Ostoja-Starzewski\, M. (2019) Finite element
  methods in human head impact simulations: A review\, Ann. Biomed. Eng. 47
 (9)\, 1832&ndash\;1854.\nChen\, Y. and Ostoja-Starzewski\, M. (2010) MRI-b
 ased finite element modeling of head trauma: spherically focusing shear wa
 ves\, Acta Mech. 213(1-2)\, 155-167.\nChen\, Y.\, Sutton\, B.\, Conway\, C
 .\, Broglio\, S.P. and Ostoja-Starzewski\, M.\, (2012) Brain deformation u
 nder mild impact: Magnetic resonance imaging-based assessment and finite e
 lement study\, in special issue "Brain Neuro-Mechanics" of Int. J. Num. An
 al. Model. Ser. B 3(1)\, 20-35\, 2012.\nMadhukar\, A. and Ostoja-Starzewsk
 i\, M. (2020) Modelling and simulation of head trauma utilizing white matt
 er properties from magnetic resonance elastography\, Modelling 1\, 225-241
 \, 2020. Supplementary Material: simulation movie.\nMadhukar\, A. and Osto
 ja-Starzewski\, M. (2022) Blunt head impact causes a temperature rise in t
 he brain\, R. Soc. Open Sci. 9\, 220890.\nJohnson\, C.L.\, McGarry\, M.D.\
 , Gharibans\, A.A.\, Weaver\, J.B.\, Paulsen\, K.D.\, Wang\, H.\, Olivero\
 , W.C.\, Sutton\, B.P. and Georgiadis\, J.G. (2013) Local mechanical prope
 rties of white matter structures in the human brain. Neuroimage 79\, 145&n
 dash\;152.\nNahum\, A.\, Smith\, R. and Ward\, C. (1997) Intracranial pres
 sure dynamics during head impact. Proc. 21st Stapp Car Crash Conf.\, 339&n
 dash\;366.\n
LOCATION:Seminar Room 2\, Newton Institute
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