Improved quantification precision of human brain short echo‐time 1 H magnetic resonance spectroscopy at high magnetic field: A simulation study

Purpose The gain in quantification precision that can be expected in human brain 1 H MRS at very high field remains a matter of debate. Here, we investigate this issue using Monte‐Carlo simulations. Methods Simulated human brain‐like 1 H spectra were fitted repeatedly with different noise realizations using LCModel at B 0 ranging from 1.5T to 11.7T, assuming a linear increase in signal‐to‐noise ratio with B 0 in the time domain, and assuming a linear increase in linewidth with B 0 based on experimental measurements. Average quantification precision (Cramér–Rao lower bound) was then determined for each metabolite as a function of B 0 . Results For singlets, Cramér–Rao lower bounds improved (decreased) by a factor of ∼B 0as B 0 increased, as predicted by theory. For most J ‐coupled metabolites, Cramér–Rao lower bounds decreased by a factor ranging fromB 0to B 0 as B 0 increased, reflecting additional gains in quantification precision compared to singlets owing to simplification of spectral pattern and reduced overlap. Conclusions Quantification precision of 1 H magnetic resonance spectroscopy in human brain continues to improve with B 0 up to 11.7T although peak signal‐to‐noise ratio in the frequency domain levels off above 3T. In most cases, the gain in quantification precision is higher for J ‐coupled metabolites than for singlets. Magn Reson Med 72:20–25, 2014. © 2013 Wiley Periodicals, Inc .