A reproducible MRI-to-FE framework for generating population-specific and subject-specific finite element head models

Traumatic brain injury (TBI) remains a global health challenge with mechanisms that are still insufficiently understood. While neuroimaging has been used to probe microstructural alterations and their association with head kinematics, findings remain heterogeneous. Finite element (FE) head modelling offers a more robust alternative, demonstrating a superior correlation with observed microstructural changes compared to traditional impact exposure metrics. However, most existing FE models are derived from single-subject scans or generic atlases, which often fail to represent specific study cohorts and introduce significant output variability. This study presents a reproducible computational framework that generates a cohort-specific template brain from MRI scans of adolescent male rugby players to produce a representative FE head model. The model was validated against cadaveric head experiments, demonstrating strong agreement with observed nodal displacements. Furthermore, simulations comparing the template-based model to subject-specific FE models with the identical impact conditions revealed significant differences in brain response. These results underscore the critical necessity of subject-specific modelling for the personalised characterisation of brain biomechanics. Our framework utilizes open-access tools, ensuring full reproducibility for research groups seeking to develop population-, sex-, or ethnicity-specific models. By providing a more accurate representation of cohort-average and individual brain responses, this work contributes to the improved mapping of mechanical strain to clinical findings and neurological alterations.