High-field downfield magnetic resonance spectroscopic imaging in the human brain

Motivation: Downfield (DF) MR spectroscopic imaging (MRSI) is a promising new metabolic imaging technique that has previously been demonstrated in the human brain at 3T. This abstract describes initial results of 3D DF-MRSI at 7T. Goal(s): To implement and test 3D DF-MRSI at 7T. Approach: The 3D DF-MRSI pulse sequence was adapted for 7T and tested on 4 healthy volunteers. Results: High-field DF-MRSI with 0.7 mm3 nominal voxel resolution is feasible. Concentration and uncertainty estimates for the 9 downfield peaks and combined amide resonances from selected voxels were not significantly different, except for DF6.83 which was significantly lower in the CSO than DLPFC (p=0.007). Impact: High-field DF-MRSI should now be able to spatially map the exchangeable protons in human brain within clinically acceptable times and accuracy to be used in future studies of brain tumors or other neuropathological disorders.