I. Introduction
In [8], Basser et al. presented their seminal work on diffusion tensor magnetic resonance imaging (DT-MRI). Since this new MRI modality can be used to quantify anisotropic properties of the imaged tissue by characterizing the water diffusion through the same, it has became a powerful technique to investigate the tissue microstructure in vivo, e.g., white matter connectivity in the brain or in the spinal cord. Investigating the tissue microstructure and changes therein (due to pathology) is achieved via DTI analysis. This in general includes a broad spectrum of interesting problems namely, optimal DT-MR imaging protocol design, DTI restoration, DTI segmentation, DTI registration, DTI visualization and fiber track mapping.