Going for Glutamine: Evaluation of Asymmetric PRESS Approaches

Caroline Rae¹, Guangqiang Geng¹, Stephen R. Williams²

Glutamine measurement is problematic using single-shot methods at 3T. Here, we evaluate in vivo, recommended PRESS timings, optimized asymmetric PRESS (A-PRESS) timings and a variant A-PRESS designed to minimize overlap of glutamine with the aspartyl moiety of NAA. Standard deviations of estimates were determined using the QUEST algorithm from jMRUI and appropriate metabolite basis sets. A-PRESS was found to be significantly better than PRESS for Gln determination and comparable with standard PRESS for glu, NAA, Cho and Cre. Use of the variant A-PRESS may also help improve estimate precision for Gln.