Fractional anisotropy refers to how much water molecules move in different directions within the brain's white matter. It helps to show the structural connections between different brain regions. Full definition
(a) Axial and (b) coronal images show regions of decreased fractional anisotropy in male patients with mTBI relative to female mTBI patients, involving the uncinate fasiculus (red) bilaterally. (sciencedaily.com)
Frey et al (2012) established a novel approach for fiber tracking based on navigated TMS mapping of the primary motor cortex and proposed a new algorithm for determination of an individualized fractional anisotropy value for reliable and objective fiber tracking. (aetna.com)
DTI produces a measurement, called fractional anisotropy (FA), of the movement of water molecules along axons. (sciencedaily.com)