A comprehensive technique was developed for using three-dimensional 17O magnetic resonance spectroscopic imaging at 9.4T for rapidly imaging the cerebral metabolic rate of oxygen consumption (CMRO2) in the rat brain during a two-min inhalation of 17O2. The CMRO2 value (2.19 ± 0.14 μmol/g/min, n = 7) was determined in the rat anesthetized with α-chloralose by independent and concurrent 17O NMR measurements of cerebral H217O content, arterial input function, and cerebral perfusion. CMRO2 values obtained were consistent with the literature results for similar conditions. Our results reveal that, because of its superior sensitivity at ultra-high fields, the 17O magnetic resonance spectroscopic imaging approach is capable of detecting small dynamic changes of metabolic H2 17O during a short inhalation of 17O2 gas, and ultimately, for imaging CMRO2 in the small rat brain. This study provides a crucial step toward the goal of developing a robust and noninvasive 17O NMR approach for imaging CMRO2 in animal and human brains that can be used for studying the central role of oxidative metabolism in brain function under normal and diseased conditions, as well as for understanding the mechanisms underlying functional MRI.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Oct 1 2002|