Hyperpolarized 13C bicarbonate-to-pyruvate ratio correlates with excitatory neuron spatial distribution in the human brain

Motivation: Hyperpolarized 13C MRI (HP 13C-MRI) imaging of the whole-brain provides contrast that is proportional to underlying metabolic processes. Consistent patterns of regional HP 13C-MRI metabolite signal distribution in the healthy human brain have been observed, but it's not clear what drives these patterns. Goal(s): We hypothesized that regional patterns of HP 13C-MRI signal distribution would correspond to cell-type distributions in the brain. Approach: Gene data from a database of post-mortem brains was correlated with HP 13C-MRI signal (n = 43) through a statistically robust transcriptomic analysis. Results: HP 13C-bicarbonate signal, an indirect marker of oxidative metabolism, correlated with excitatory neuronal cell populations. Impact: We found that there was a pattern of neuron cell distribution in the healthy brain that correlates with hyperpolarized 13C-signal topography. These results provide a better understanding of the physiology driving hyperpolarized 13C-signal patterns in healthy human brains.