PET provides a unique array of tools for brain investigations.
Innovative design of these tracers permits selective measurement of many aspects of brain function, and their short halflives permit rapid, repeated scans over a time period that is practical for studies in patients. Furthermore, quantitatively accurate reconstruction algorithms permit measurements of radioactivity concentrations in small regions of the brain with high precision and temporal sampling. To interpret these data, tracer kinetic models are developed for each radiopharmaceutical to convert the radioactivity images into measurements of physiologically relevant variables such as blood flow, metabolism, and receptor number. Powerful statistical and image analysis techniques have been developed to analyze data from multiple subjects rapidly, to extract the subtle biological signals that are produced by activation of the brain, and to identify sites of impaired function. The research areas that encompass brain PET, i.e., radiochemistry, instrumentation and quantification, modeling, and image analysis, interact in the development and application of PET methods.