Modern brain imaging technologies play essential roles in our understanding of brain information processing and the mechanisms of brain disorders. Magnetic Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) can image the anatomy and structure of the brain. In addition, functional MRI (fMRI) can identify active regions, patterns of functional connectivities and functional networks during either tasks that are specifically related to various aspects of brain function or during the resting state. The merging of such structural and functional information obtained from brain imaging may be able to enhance our understanding of how the brain works and how its diseases can occur. In this paper, we will review advances in both methodologies ...