Reproducibility of HERMES-measured GABA+ and GSH in the Mesial Temporal Lobe

Motivation: Quantification of measurement reproducibility of in vivo MRS experiments enables the planning of future studies. Evidence of reproducibility of simultaneous measurement of GABA and GSH using Hadamard-encoded spectral editing (i.e., HERMES) in challenging brain regions for MRS, such as the mesial temporal lobe (MTL), is needed. Goal(s): Determine the reproducibility of HERMES-sLASER in the MTL. Approach: Two MTL HERMES scans were acquired in 15 participants, with participants repositioned between scans. Results: The average CV for GABA+ was 14.09% and the average CV for GSH was 18.94%, comparable to previous work investigating these metabolites in the MTL using standalone acquisitions. Impact: This study quantifies the reproducibility of HERMES-sLASER in the challenging region of the mesial temporal lobe. These results show that this technique can be used to measure multiple metabolites by editing them simultaneously and provides guidance on expected effect sizes.