**6. Structural neuroimaging and exercise impact**

What type of neuroimaging is best when trying to determine how exercise impacts the [aging] brain? That depends on the question(s) one needs to answer. If the goal is to determine the long-term impact of exercise on brain structure, then structural MRIs are appropriate. Structural imaging can track changes over time due to a stimulus such as exercise. Structural imaging can involve gray and white matter volume determination ("quantity"), cerebral white matter integrity ("quality") using diffusion tensor imaging (DTI), or both. It can also involve investigating the cerebral blood vessels utilizing magnetic resonance angiography (MRA).
