Diffusion tensor imaging (DTI) is a noninvasive magnetic resonance (MR) technique for investigating tissue microstructure and white matter architectural organization in the brain. In this talk, we will present a basic introduction to DTI and give a guided tour through recent developments in the analysis of diffusion tensors from the least squares estimations of the diffusion tensor to the elliptical cone of uncertainty for characterizing uncertainty of the major eigenvector (or principal axis) of the diffusion tensor.