Dynamic mapping of Glc oxidative metabolism in rats with indirect 1H-FID-MRSI deuterium detection at 9.4T

Motivation: Deuterium metabolic imaging shows great potential to non-invasively map regional glucose oxidative metabolic fluxes in the brain. However, reaching sufficient spatial and temporal resolution in preclinical setups remains a challenge. Goal(s): Achieve a satisfactory balance between SNR, spatial and temporal resolution to characterise glucose oxidative metabolism into glutamate+glutamine (Glx) turnover. Approach: An optimised 1H-FID-MRSI protocol was used at 9.4T with a cryogenic receive RF probe to characterise 2H labelling through signal decay. Results: Dynamic 1H-FID-MRSI upon continuous infusion of 2H-labelled Glc enabled the reproducible measurement of regional Glx turnover curves in the rat brain. Impact: Our work shows the potential of recently developed preclinical 1H-FID-MRSI protocols to track 2H labelling in downstream glucose metabolism in a quantitative way, with sufficient SNR to characterise the time course of glutamate-glutamine turnover with regional specificity.