This image of a concussion patient's brain shows low FA areas (red) probably signifying injured white matter, plus high FA areas (blue) perhaps indicating more efficient white-matter connections compensating for concussion damage. A large amount of high FA predicts recovery from concussion.
Photo reproduced from Strauss SB, Kim N, Branch CA. Bidirectional Changes in Anisotropy Are Associated with Outcomes in Mild Traumatic Brain Injury. AJNR Am J Neuroradiol 2016 Jun 9. [Epub ahead of print]