Purpose: To investigate the utility of an advanced magnetic resonance spectroscopy (MRS) protocol in the clinical setting, and to compare the localization accuracy, spectral quality, and quantification repeatability between this advanced and the conventional vendor-provided MRS protocol on a clinical 3T platform. Methods: Proton spectra were measured from the posterior cingulate cortices in 30 healthy elderly subjects by clinical MR technologists using a vendor-provided (point resolved spectroscopy with advanced 3D gradient-echo B0 shimming) and an advanced (semi-LASER with FAST(EST)MAP shimming) protocol, in random order. Spectra were quantified with LCModel using standard pipelines for the clinical and research settings, respectively. Results: The advanced protocol outperformed the vendor-provided protocol in localization accuracy (chemical-shift-displacement error: 2.0%/ppm, semi-LASER versus 11.6%/ppm, point resolved spectroscopy), spectral quality (water linewidth: 6.1 ± 1.8 Hz, FAST(EST)MAP versus 10.5 ± 3.7 Hz, 3D gradient echo; P < 7e-6; residual water: 0.08 ± 0.12%, VAPOR versus 0.45 ± 0.50%, WET; P < 2e-5) and within-session repeatability of metabolite concentrations, particularly of low signal-to-noise ratio data with two to eight averages (test-retest coefficients of variance of metabolite concentrations, P < 0.01). Concentrations of J-coupled metabolites such as γ-aminobutyric acid and glutamate were biased when using the default pipeline with simulated macromolecules. Conclusions: The quality of MRS data can be improved using advanced acquisition and analysis protocols on standard 3T hardware in the clinical setting, which can facilitate robust applications in central nervous system diseases. Magn Reson Med 79:1241–1250, 2018.
Bibliographical noteFunding Information:
This work was supported by funding from the Minnesota Partnership for Biotechnology and Medical Genomics and NIH grants R01 NS080816, P41 EB015894, P30 NS076408, and R01 AG040042. *Correspondence to: Dinesh K. Deelchand, Ph.D., Center for Magnetic Resonance Research, University of Minnesota, 2021 6th St SE, Minneapolis, MN 55455, USA. Tel: (1) 612-625-8097; Fax: (1) 612-626-2004; E-mail: email@example.com.
© 2017 International Society for Magnetic Resonance in Medicine
- chemical shift displacement