Charles H. Cunningham

In this study, hyperpolarized 13 C MRI (HP‐ 13 C MRI) was used to investigate changes in the uptake and metabolism of pyruvate with age. Hyperpolarized 13 C‐pyruvate was administered to healthy aging individuals ( N = 35, ages 21–77) and whole‐brain spatial distributions of 13 C‐lactate and 13 C‐bicarbonate production were measured. Linear mixed‐effects regressions were performed to compute the regional percentage change per decade, showing a significant reduction in both normalized 13 C‐lactate and normalized 13 C‐bicarbonate production with age: per decade for 13 C‐lactate and per decade for 13 C‐bicarbonate. Certain regions, such as the right medial precentral gyrus, showed greater rates of change while the left caudate nucleus had a flat 13 C‐lactate versus age and a slightly increasing 13 C‐bicarbonate versus age. The results show that both the production of lactate (visible as 13 C‐lactate signal) as well as the consumption of monocarboxylates to make acetyl‐CoA (visible as 13 C‐bicarbonate signal) decrease with age and that the rate of change varies by brain region.