Oxygen metabolism, oxygen extraction and positron emission tomography: Historical perspective and impact on basic and clinical neuroscience

Oxygen utilization is central to the human brain's high metabolic rate. Measurement of this fundamental process, in both disease and health, has been a focus of research attention over the last 35years. This review plots the course of the use of oxygen-15 to study regional cerebral oxygen extraction and metabolism using Positron Emission Tomography (PET) in disease and in health. The scientific discoveries and resulting conceptual changes to both basic and clinical neuroscience, as well as the new methodological approaches brought about by this area of research, are also summarized. We conclude with a brief overview of the current status of oxygen-15 PET in neuroscience, along with our visions for future developments and applications. ► Oxygen-15 has been used to measure regional cerebral oxygen metabolism and extraction. ► Its use for researching a range of brain disorders and normal functions is reviewed. ► Focally increased oxygen extraction fraction indicates regional cerebral ischemia. ► Oxygen extraction fraction decreases in physiological cerebral activation. ► 15O-PET has revolutionized several key physiological and pathophysiological concepts.