Increased Cerebral Lactate-to-Pyruvate Ratio in Primary Progressive Multiple Sclerosis using Hyperpolarized Pyruvate MRI.
McGing J., Pisa M., Lockhart A., Yeung K., Axford A., Mills R., Shinozaki A., Lewis A., Birkhoelzer S., Berner L., Zaccagna F., Schulte R., Rider O., De Luca G., Tyler D., Grist J.
Motivation: There remains an absence of imaging modalities capable of probing the neuroinflammatory processes that precede the well-defined brain structural changes in Primary Progressive Multiple Sclerosis (PPMS). Goal(s): We investigated whether hyperpolarized [1-13C]pyruvate MRI can delineate alterations in cerebral glycolytic and oxidative metabolism between treatment naïve PPMS and healthy volunteers. Approach: Two treatment naïve PPMS patients and two sex matched healthy volunteers underwent [1-13C]pyruvate MRI to characterise cerebral glycolytic and oxidative metabolism. Results: A global increase in [1-13C]lactate: [1-13C]pyruvate was found in both PPMS patients relative to sex-matched healthy controls (0.23 ± 0.12 vs 0.16 ± 0.08). The 13C bicarbonate:[1-13C]pyruvate ratio was no different. Impact: These preliminary findings demonstrate a global increase in cerebral glycolytic metabolism in treatment naïve PPMS relative to age and gender matched healthy controls. This may reflect diffuse neuroinflammatory processes and suggests [1-13C]pyruvate MRI could be used to monitor disease activity.