[Basic principles of diffusion tensor MR tractography].

Abstract

Diffusion tensor MR tractography allows in vivo depiction of anatomical bundles composing the white matter of the brain and of spinal cord. Diffusion MRI uses the effects of heterogeneous water molecule movement to determine for each pixel the main axis and magnitude of local anisotropy. Tractography exploits these data to reconstruct the tridimensional geometry of the bundles providing neurologists with precise information about white matter tract architecture involvement by various pathologies. In this paper, the basic principles of molecular diffusion and the subsequent diffusion tensor that describes its geometrical and quantitative characteristics will be reviewed, in particular within bundles of white matter. Then main principles of diffusion tensor MR imaging and tractography will be presented.