Neuropsychologist researcher and professor Erin Bigler, PhD. recently spoke about the advances in images of post-concussion brains. 
As discussed here, concussions or mild traumatic brain injuries may not show up on standard MRI or CT images. Dr. Bigler described a new technique for analyzing MRI scans called “diffusion tensor imaging” or DTI. This technique illustrates the direction of water flow through the fiber tracts of the brain. A comparison of images between an injured group and a control group revealed differences in the fiber tracts of injured patients. It is believed that the head injuries caused swelling or edema in the fiber tracts, disrupting their normal ability to transmit messages in the brain. This imaging allows researchers to determine the extent of injury between the fiber tracts. Such research will have many applications, including diagnosing and assessing the scope of damage to a mild traumatic brain injury victim.
