Contrast enhanced magnetic resonance imaging highlights neurovasculature changes following experimental traumatic brain injury in the rat

Neurovascular injury has been proposed as a universal pathological hallmark of traumatic brain injury (TBI) with molecular markers of angiogenesis and endothelial function associated with injury severity and morbidity. Sex differences in the neurovasculature response post-TBI may contribute to the differences seen in how males and females respond to injury. Steady-state contrast enhanced magnetic resonance imaging (SSCE-MRI) can be used to non-invasively assess the neurovasculature and may be a useful tool in understanding and predicting outcomes post-TBI. Here we used SSCE-MRI to investigate the neurovasculature of male and female rats at 48 h after an experimental TBI, and how these changes related to neuromotor function at 1-week post-TBI. In addition to TBI induced changes, we found that female rats had greater vessel density, greater cerebral blood volumes and performed better on a neuromotor task than their male counterparts. These results suggest that acute post-TBI cerebrovascular function is worse in males, and that this may contribute to the greater functional deficits observed post-injury. Furthermore, these results highlight the potential of SSCE-MRI to provide insights into the cerebral microvasculature post-TBI. Future studies, incorporating both males and females, are warranted to investigate the evolution of these changes and the underlying mechanisms.