Fractional Anisotropy

Fractional anisotropy (FA) is a quantitative measure of the directional dependence of the diffusion of water molecules in a tissue. It is used to assess the degree of neural organization in the brain and other organs. FA is highly sensitive to changes in the structure of the tissue, and its value increases with higher levels of organization. By measuring FA, medical researchers can detect changes in the brain’s organization and structure caused by diseases or disorders such as multiple sclerosis, Alzheimer’s, or stroke. As such, it is a valuable tool in the diagnosis, treatment and prognosis of numerous neurological conditions.