Back to the future: Estimating pre-injury brain volume in patients with traumatic brain injury.

•A method was developed to estimate brain volume just before the time of injury.•TBI led to decrease in cerebral white matter volume and increase in other regions.•The magnitude and pattern of changes was possibly unique among brain disorders.•Regression analysis showed perfect prediction of group membership (TBI vs. normal).•This approach may lead to a method for diagnosing mild or moderate TBI using MRI.