ABSTRACT
The first imaging technique developed to allow visualization of the living brain, the computer assisted tomography (CAT) scan, interposes the head between a source which emits a narrow beam of X-rays and an X-ray detector. A remarkable feature of positron emission tomography (PET) is that it provides insights into the function of the living brain as well as its anatomy. The importance of PET in functional studies is illustrated by the use of the nonmetabolizable analog of glucose, 2-deoxyglucose (2-DG). Like PET, magnetic resonance imaging (MRI) provides information about brain function as well as anatomy. It combines computerized tomography with nuclear magnetic resonance. Functional MRI has numerous clinical uses: mapping cerebral blood vessels, showing changes in extracellular space that accompany trauma or inflammation, diagnosis and following the progress of a variety of diseases, and the precise localization of regions of stroke damage or tumors.
