Preclinical ¹H MRS at Ultra-High Field: A Comparative Study of LASER and STEAM Sequences in Mouse Brain

Motivation: At ultra-high magnetic fields (UHF), shortened T₂ relaxation times of water and metabolites necessitate efficient magnetic resonance spectroscopy (MRS) sequences like STEAM and LASER. Goal(s): To compare the neurochemical profiles obtained using LASER and STEAM sequences in the mouse brain at 11.7 T. Approach: Short echo-time LASER (TE = 16.75 ms) and STEAM (TE/TM = 2.7/10 ms) MRS data were acquired from the caudate-putamen region in nine adult female C57BL/6 mice. Results: Neurochemical profiles from both sequences were highly correlated (r = 0.97), with LASER showing a twofold increase in SNR compared to STEAM. Impact: LASER's higher SNR can reduce scan time in preclinical studies at UHF, enabling more efficient data acquisition and facilitating advanced applications like dynamic MRS and neurochemical profiling of smaller brain structures.