distributions and a classic bit of geometric tomography and vector math developed nearly 100 years ago—the Funk Radon Transform. Summary For DTI, it is generally possible to use linear algebra, matrix mathematics and vector mathematics to process the analysis of the tensor data. In some cases, the full set of tensor properties is of interest, but for tractography it is usually necessary to know only the magnitude and orientation of the primary axis or vector. This primary axis—the one with the greatest length—is the largest eigenvalue and its orientation is encoded in its matched eigenvector. Only one axis is needed as it is assumed the largest eigenvalue is aligned with the main axon direction to accomplish tractography. See also Connectogram Connectome Tractography Explanatory notes References External links PNRC: About Diffusion MRI White Matter Atlas Imaging Tensors Neuroimaging Magnetic resonance imaging de:Diffusions-Tensor-Bildgebung