Advances in longitudinal MRI diagnostic tests.

Introduction: The past decade has seen an explosion of functional magnetic resonance imaging (MRI) studies in neuroscience. As the technology progresses, it is now possible to carry out longitudinal studies using functional MRI. Such studies can be used to understand the progression of mental and neurological disorders and the effectiveness of different treatments by obtaining direct measures of brain activity as well as markers of tissue health and connectivity.

Areas covered: We review six popular neuroimaging tools that can be used for longitudinal studies: blood oxygen level-dependent (BOLD)-weighted imaging, BOLD-based functional connectivity, arterial spin labeling, dynamic R2* imaging, voxel-based morphometry, and diffusion tensor imaging.

Expert opinion: Each of these techniques is targeted to probe a specific feature of brain function or brain structure and can reveal important information about the progression of a pathological condition. We anticipate that in the near future, the MRI techniques discussed here may become standard tools in clinical use and will not be used for research purposes only.