Two‐dimensional J ‐resolved proton MR spectroscopy and prior knowledge fitting (ProFit) in the frontal and parietal lobes of healthy volunteers: Assessment of metabolite discrimination and general reproducibility

Purpose: To investigate human brain metabolite discriminability and general measurement reproducibility of two‐dimensional (2D) J ‐resolved 1 H MRS and Prior Knowledge Fitting (ProFit). Materials and Methods: 2D J ‐resolved 1 H MRS spectra were acquired from the anterior cingulate cortex (ACC) and the parietal‐occipital cortex (POC) of 10 healthy subjects at a magnetic field strength of 2.9 Tesla. Amplitude correlation matrices were constructed for each subject and brain region to assess metabolite discriminability. ProFit‐estimated metabolite peak areas were normalized to a water reference signal, and intra‐ and inter‐subject reproducibility was evaluated. Results: Favorable between‐metabolite correlation coefficients (<20%) were observed for a range of metabolites. Lower correlation coefficients between a given pair of metabolite estimates were consistently observed for POC metabolites. The group mean correlation coefficient existing between glutamate and glutamine was calculated as −18% and −13% for ACC and POC, respectively. Most ACC and POC metabolites showed intra‐ and inter‐subject CV values of <15% and <20%, respectively. Conclusion: The observed Glu and Gln signal discrimination makes these techniques suitable for investigating a variety of psychiatric disorders. Intra‐ and inter‐subject metabolite level reproducibility was comparable to the existing literature findings. These data serve as a valuable benchmark for assessing future modifications to 2D 1 H MRS data acquisition and ProFit analysis. J. Magn. Reson. Imaging 2013;37:642–651. © 2012 Wiley Periodicals, Inc.