The MOTION study – First quantitative muscle MRI results in a large cross-sectional cohort of healthy subjects

Motivation: The overall aim of our ongoing study MOTION is to connect whole leg quantitative MRI (qMRI) and muscle structure to function and lifestyle in 162 healthy volunteers. Goal(s): Preliminary analysis of 31 subjects to identify potential covariates that may impact qMRI measurements. Approach: Muscle fat fraction (FF), mean diffusivity (MD), fractional anisotropy (FA) and T2water were determined in 20 muscles from tendon to tendon bilaterally, and related to age, gender, and body composition. Results: Muscle FF is higher in heavier subjects with more body fat. FA is lower and MD and volume are higher in larger subjects. T2water depends on age and gender. Impact: Accounting for covariates describing body composition (BMI, lean body mass and body fat mass) on top of gender and age is crucial for proper interpretation of quantitative muscle MRI in clinical studies on neuromuscular disease patients and healthy controls.