Accelerated quantification of muscular tissue sodium concentrations at 7 Tesla

Motivation: 23Na MRI at 7T is a useful tool for assessing tissue health and studying muscle diseases, but long acquisition times limit its clinical application. Goal(s): This study aimed to accelerate the quantitative measurement of apparent tissue sodium concentration (aTSC) by reducing voxel size. Approach: The calves of ten volunteers were measured with 23Na MRI at 7T using three different voxel sizes. Partial volume correction (PVC) was applied in post-processing based on 1H image segmentation. Results: Increasing voxel size raised aTSC estimates significantly. PVC minimized deviations to ≈1 mM, reducing scan time from 8:04 to 2:41 minutes. Impact: Quantification of aTSC in the calf at reduced resolutions is possible, which significantly shortens the measurement time for clinical studies. However, when using this method, small but significant deviations in the aTSC values are to be expected.