Mastering preclinical proton and deuterium-based fast MRSI in the brain: from setup to execution

MR experiments are essential for studying brain metabolism, yet preclinical MRSI remains underdeveloped, with significant limitations in SNR, acquisition speed, and automated data processing. Although recent advances-such as accelerated sequences, denoising strategies, and ultra-high-field systems-have begun to reduce these barriers; preclinical MRSI still lags far behind the human research field in accessibility and routine use. Based on our expertise, we have created this guide that outlines a complete workflow for acquiring and analyzing high-quality fast-proton and deuterium-based MRSI data in rodent brains at ultra-high fields (9.4 T and 14.1 T), enabling novice users to perform reliable experiments using optimized MRSI sequences (FID-MRSI, SE-MRSI, and PRESS-MRSI) and standardized processing pipelines, while also highlighting strategies to further improve acquisition speed, coverage, and reproducibility. Overall, this paper provides a strong foundation for future methodological advances that will expand metabolic imaging capabilities and deepen insights into brain metabolism and disease.