Non-Invasive Real-Time Detection of Potassium Level Changes in Skeletal Muscles During Exercise by Magnetic Resonance
Etienne Roesli1,2, Hedvika Haindrich Primasová1,2, Marc Thiede1,2
1Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland.
NMR in Biomedicine
|November 11, 2025
Summary
This study demonstrates that 39K magnetic resonance spectroscopy (MRS) can non-invasively track real-time intracellular potassium changes in muscle during exercise. The technique shows promise for monitoring muscle physiology and metabolic disorders.
Area of Science:
- Physiology
- Biophysics
- Medical Imaging
Background:
- Potassium is a vital intracellular cation crucial for muscle and cardiovascular health.
- Traditional potassium measurement methods are invasive and lack intracellular specificity.
- Non-invasive in vivo potassium homeostasis investigation is emerging with 39K MRI/MRS at ultrahigh fields.
Purpose of the Study:
- To utilize 39K MRS for non-invasive, real-time tracking of intramuscular potassium changes during exercise.
- To assess potassium dynamics in skeletal muscle during physical exertion.
- To evaluate potential measurement artifacts in 39K MRS during dynamic exercise.
Main Methods:
- Five healthy subjects performed knee extensions in a 7T MR scanner.
- A 39K MRS protocol measured potassium levels during rest, moderate, heavy exercise, and recovery.
- 1H MRI monitored potential movement artifacts.
Main Results:
- A consistent 5%-6% decrease in intramuscular potassium was observed during moderate and heavy exercise.
- Potassium level changes were rapidly detectable and reversed post-exercise.
- Investigated artifacts were not responsible for the observed potassium changes.
Conclusions:
- 39K MRS is a valuable non-invasive tool for studying potassium dynamics in human skeletal muscle.
- The technique enables real-time, in vivo monitoring of potassium shifts during exercise.
- This method holds potential for understanding muscle physiology and clinical applications in metabolic disorders.
