Impact of gradient scheme and non-linear shimming on out-of-voxel echo artifacts in edited MRS.

ABSTRACT: Out-of-voxel (OOV) signals are common spurious echo artifacts in MRS. These signals often manifest in the spectrum as very strong "ripples," which interfere with spectral quantification by overlapping with targeted metabolite resonances. Dephasing optimization through coherence order pathway selection (DOTCOPS) gradient schemes are algorithmically optimized to suppress all potential alternative coherence transfer pathways (CTPs), and should suppress unwanted OOV echoes. In addition, second-order shimming uses non-linear gradient fields to maximize field homogeneity inside the voxel, which unfortunately increases the diversity of local gradient fields outside of the voxel. Given that strong local spatial B₀ gradients can refocus unintended CTPs, it is possible that OOVs are less

SUBMITTER: Song Y 

PROVIDER: S-EPMC9845189 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature