Background

23Na magnetic resonance imaging (23Na-MRI) is able to measure Na+ in vivo in humans and allows quantification of tissue sodium distribution. We now tested the utility of 23Na-MRI technique in detecting and assessing sports-related acute muscular injury.

Case presentation

We assessed tissue Na+ of both lower legs with a 3T MRI scanner using a customized 23Na knee coil. The affected left calf muscle in an injured volleyball player showed a hyperintense Na+ signal. Follow-up measurements revealed persistently increased muscle Na+ content despite complete clinical recovery.

Conclusions

Our findings suggest that 23Na-MRI could have utility in detecting subtle muscular injury and might indicate when complete healing has occurred. Furthermore, 23Na-MRI suggests the presence of substantial injury-related muscle electrolyte shifts that warrant more detailed investigation.