Reproducibility of in vivo measurements of carnosine in muscles with 1H-MR spectroscopy

Motivation: Due to its pH-buffering function in skeletal muscle, carnosine reveals muscle fibre specific concentrations and is therefore suitable as a marker for the evaluation of muscle fibre composition in pathologies. Goal(s): This study examines the reproducibility of muscle carnosine quantitation with 1H-MRS, and is further targeting to adjust scan parameters for future clinical studies. Approach: 1H-MRS was applied in healthy volunteers to evaluate carnosine lateralization in leg muscles as well as quantitation reproducibility and precision in various parameter settings. Results: Muscular carnosine can be measured with a sufficient precision and reproducibility in less than four minutes and in small voxels. Impact: 1H-MRS enables reliable in vivo measurements of carnosine in skeletal muscles in clinical protocol settings, which is important for the assessment of disease- and age-related as well as myodegenerative changes in muscle fibre composition.