B1 field inhomogeneity correction of 23Na MRI for lumbar spine

Motivation: Sodium (23Na) MRI enables non-invasive evaluation of sodium concentration in lumbar spine. However, surface coil's B1 field varies spatially, therefore 23Na MR image needs to be corrected for accurate interpretation. Goal(s): Our goal was to correct the B1 field inhomogeneity on lumbar spine 23Na MRI with approach that is feasible in clinical settings. Approach: 23Na MRI was acquired on saline-filled phantom with multiple averages. Then clinical 23Na MRI was corrected for B1 inhomogeneity using phantom data. Results: Both visual and quantitative assessments demonstrated that the proposed technique reduces B1 inhomogeneity induced artefacts in lumbar spine 23Na MRI. Impact: In clinical environments where time and hardware are constrained, the proposed method would be useful for correcting the B1 field inhomogeneity for 23Na MRI. This technique can also be applied to wider regions and patient populations.