31P MRSI coil combination using 23Na sensitivity information acquired with the same loop array at 7T: preliminary verification

We utilized a quintuple-tuned RF head coil array by using the high-SNR 23Na signals from the brain to optimize the weighting for combining signals from the same coil array elements for the low-concentrated 31P metabolites. 23Na-weighted Roemer combination of 31P MRSI signals is verified on EM simulations and MR experiments. Comparing to 31P self-weighted combination, 23Na-weighted combination shows higher SNR and better-combined spectra in regions with low intrinsic SNR. It also shows potential of mitigating the signal contaminations when using 31P-self-weights for 31P data acquired with large voxels.