Reliability and Reproducibility of Metabolite Quantification Using ¹H MRS in the Human Brain at 3 T and 7 T

Proton magnetic resonance spectroscopy (¹H MRS) is a valuable non-invasive technique for quantifying biochemical compounds in vivo, facilitating the monitoring of disease progression and treatment. This study evaluates the reliability and reproducibility of ¹H MRS measurements by comparing data acquired with STEAM and sLASER sequences at 3 T and 7 T. We assessed test-retest reliability and reproducibility by scanning healthy participants twice with STEAM and sLASER at 3 T and 7 T in two different voxel locations about 1 week apart, investigating the impact of measurement conditions on results. Reliability was measured using the intraclass correlation coefficients (ICC), whereas reproducibility was assessed with the coefficients of variation (CV). Our findings reveal that data acquired with the sLASER sequence show superior reliability and reproducibility compared to STEAM for most metabolites at both fields. Although the higher field strength of 7 T provides advantages in signal-to-noise ratio and resolution as expected, our study highlights that a field strength of 3 T provides a suitable alternative when ultra-high-field scanners are unavailable. This study provides valuable insights for researchers regarding the selection of appropriate MRS sequences and field strengths based on reliability and reproducibility. Our findings underscore the importance of consistent measurements over time, guiding decisions in longitudinal studies and enhancing data consistency.