31P-MRS measured phosphocreatine recovery kinetics in human muscles during health and disease: a meta-analysis

Motivation: 31P-MRS methodology is notoriously laboratory-specific, leading to uncertainty about the normal range of PCr recovery kinetics among healthy individuals, as well correlations with disease and demographic factors. Goal(s): Our aim was to characterize the normal range of PCr recovery measurements from 31P-MRS in human skeletal muscles, as well as correlations with age and end-of-exercise pH. Approach: Included studies focused on exercise-induced skeletal muscle PCr recovery kinetics in healthy or diseased individuals, using 31P-MRS. Results: PCr recovery time is consistent across three skeletal muscle groups in healthy individuals from diverse MRI centers. Greater age and more acidic pH increase PCr recovery time. Impact: These results will set the indexes for PCr recovery kinetic measures across different human skeletal muscles.