Feasibility of in vivo metabolic profiling in the human brainstem periaqueductal gray matter by 1H-MRS at 7T

Motivation: Metabolic profiling in periaqueductal gray matter (PAG) is clinically relevant as the PAG is involved in several brain disorders. Considering PAG's small size, 7T-MRS may be beneficial for reliable metabolic profiling. Goal(s): To determine the feasibility of in vivo metabolic profiling of the human brainstem PAG at 7T. Approach: Short-TE 1H-MRS was performed using sLASER sequence at 7T in the PAG of seven young healthy volunteers. Results: Feasibility of detecting both high and low abundant metabolites in the PAG were demonstrated using 1H-MRS at 7T, which opens new avenues for targeting neurometabolic alterations associated with PAG in several brain disorders. Impact: This study demonstrates the feasibility of in vivo metabolic profiling of the small, deeply embedded PAG region using 1H-MRS at 7T, which has potential for advancing our understanding of PAG's critical role, in both health and disease.