In vivo oxygen-17 NMR for imaging brain oxygen metabolism at high field

An overview of the methodology background and the present status of in vivo O MR spectroscopy (MRS)/imaging (MRI) approach for imaging the cerebral metabolic rate of oxygen (CMRO ₂2) and studying the central roles of cerebral oxygen metabolism in brain function is presented. The brain is a highly aerobic organ; it consumes oxygen and glucose extensively in order to generate chemical energy in the form of the adenosine triphosphate (ATP) molecule. Oxygen and glucose as the major fuels for brain metabolism are continuously supplied by the circulating blood flow through the capillary bed. Unlike small animals, quantification of CMRO ₂ in humans faces serious challenges. The human body size, lung capacity and respiration rate as well as blood circulation speed are drastically different from those in the small animal. It is expected that the exchange process between non-labeled and inhaled O-labeled oxygen gases in a human lung will be much slower compared to small animals such as a rat or mouse.