Effects of physiologic human brain motion on proton spectroscopy: quantitative analysis and correction with cardiac gating.

SUMMARY: Proton MR spectroscopy is a powerful noninvasive method that enables measurement of certain brain metabolites in healthy subjects and patients with diseases. A major difficulty with clinical and research applications of in vivo proton MR spectroscopy is the variability of metabolite concentrations, especially in regions with substantial physiologic motion. In our preliminary evaluation, we tested the hypothesis that physiologic brain motion leads to lower mean metabolite concentrations and higher SDs for the measured metabolite concentrations.