Diffusion tensor imaging (DTI)

Diffusion tensor imaging (DTI) is a measure of water diffusion in brain tissue and will provide information of white matter structure in the brain on a voxel-by-voxel basis. DTI scans derive neural tract directional information using multidimensional vector algorithms typically based on three or more gradient directions, which is the minimum information in order to compute the diffusion tensor. From the diffusion tensor, diffusion anisotropy measures such as the fractional anisotropy (FA) can then be computed. The result is visualized as color-coded neuronal tracts where the x-, y- and z- directions typically are coded in red, green and blue, respectively. Recent advances in DTI measurements also allow the researcher to visualize the pathway of a bundle through brain tissue, called DTI tractography. DTI has revealed structural abnormalities related to white matter tracts in a range of psychiatric and neurological disorders and is increasingly used in clinical practice.

The figure shows color coded white matter tracts in the transverse (red), longitudinal (green) and horisontal (blue) directions.