Anisotropic finite element modelling of traumatic brain injury: A voxel-based approach

A computationally efficient 3D human head finite element model was constructed. The model includes the mesoscale geometrical details of the brain including the distinction between white and grey matter, sulci and gyri, ventricular system, foramen magnum, and the cerebrospinal fluid. We incorporate the heterogeneity and anisotropy from diffusion tensor imaging data by applying a one-to-one voxel-based correspondence between diffusion voxels and finite elements. The voxel resolution of the model was optimized to obtain a trade-off between reduced computational cost and higher geometrical details. Three sets of constitutive material properties were extracted from the literature to validate the model against intra-cranial pressure and relative motion test data within the brain. The model exhibited good agreement at pressure tests in frontal and occipital lobes with peak pressure magnitudes of only 8% and 6% higher which occurred 0.5-3 ms earlier than those of the experimental curves at coup and countercoup sites, respectively. In addition, the evaluation of the relative displacement at six locations within the brain indicated acceptable agreement with experimental data, with our model’s performance exhibiting the highest overall score compared to several previous models by using the correlation and analysis rating method.