Some have their most important applications in medical diagnosis, and some are used more for research. The latter are often too expensive or limited for cost-efficient medical use, but can prove valuable and necessary in the future through development and further advances. There are two main groups of procedures. Structural analysis is used to analyze the anatomy of the brain, in order to find structural deviations. These could be tumors, hemorrhages, blood clots and lesions, or even deficits present at birth.
Functional analysis tries to measure and locate brain activity.
This is useful for investigating the functioning of special structures, and to diagnose epileptic seizures or diseases affecting brain activity. Functional imaging is also used to aid surgical treatment of brain lesions when it becomes necessary to determine the locality of essential functional cortex to help guide the best surgical approach. Many times a structural and functional method will be used in conjunction to better assess how the activity and region are related.