In addition to anatomy and pathology, however, MRI can also be made to report on brain physiology and function. Physiology is mapped using methods which yield quantitative estimates of parameters such as cerebral blood flow and the cerebral metabolic rate of oxygen consumption. These methods combine MRI with a variety of classical tracer techniques, including both steady-state and dynamic techniques, using both endogenous and exogenous tracers.
Function is mapped using methods which reveal neural regions subserving cognitive tasks.
These methods exploit deoxyhemoglobin as an endogenous contrast agent reporting on hyperemia concomitant to neural activation. Recent work has demonstrated that this approach can be extended to investigational functional mapping of the entire human brain.