High temporal resolution dynamic 23Na-MRI in skeletal muscle following exercise

Atypical Na+ regulation following exercise can be indicative of skeletal muscle dysfunction. Dynamic 23Na-MRI of signal recovery following exercise therefore holds potential to provide a sensitive, quantitative, and non-invasive tool for physiological monitoring of disease progression or response to interventions. 23Na-MRI sequences with temporal resolutions ranging from 2-8 minutes were acquired in the lower leg before and repeatedly after strenuous isometric dorsiflexion. Our data characterised sodium dynamics during recovery from exercise, and demonstrated an initial increase in 23Na signal intensity from baseline levels after exercise ceased. These findings may provide additional metrics for monitoring skeletal muscle dysfunction.