Non-Water-Suppressed Semi-LASER Localization for MR Spectroscopy of the Human Skeletal Muscle at 3T

Motivation: Due to the dependence on the type and orientation of the skeletal muscle, it is a challenge to perform 1H MRS to characterize the muscle features in this highly organized structure. Goal(s): The aim of this work was to implement a non-water-suppressed semi-LASER (sLASER) sequence to characterize up- and downfield metabolites in human skeletal muscle in vivo at 3T. Approach: This was achieved through optimizing the crusher scheme and phase cycling schemes in sLASER and combining it with metabolite cycled. Results: High quality spectra were obtained from different muscle fibers of 8 healthy volunteers to characterize both up- and downfield metabolites. Impact: We demonstrated the application of metabolite-cycled semi-LASER spectroscopy in human skeletal muscles at 3T. Up- and downfield parts of the spectrum were detected with high quality enabling the detection of important metabolites including carnosine providing unique insight into human physiology.