Traumatic brain injury (TBI) today is the strongest epigenetic risk factor for Alzheimer's disease (AD) . To date, the underlying mechanisms of these comorbidities are still unclear, which has hindered diagnosis and monitoring. We have investigated the effect of TBI in a PR5 tauopathy model using Diffusion Tensor Imaging and histology. We concluded that neuroinflammation is a key trigger in worsening taupathy accumulation and MRI can detect this cascade of events at an early stage. This study will enhance our understanding, not only of the effect of TBI progression in AD, but the potential of MRI for translational purposes.