Sodium quantification in skeletal muscle: comparison between Cartesian gradient-echo and radial ultra-short echo time 23 Na MRI techniques.

• Differences in MRI acquisition methods hamper the comparability of sodium MRI measurements. • Measured sodium values depend on used MRI sequences and calibration method. • Relaxation correction during postprocessing mitigates these discrepancies. • Thus, relaxation correction enhances accuracy of sodium MRI, aiding its clinical use.