Multi-center reproducibility of neurochemical profiles in the human brain at 7 T

B. L. van de Bank, U. E. Emir, V. O. Boer, J. J. A. van Asten, M. C. Maas, J. P. Wijnen, H. E. Kan, G. Oz, D. W. J. Klomp, T. W. J. Scheenen
2015 NMR in Biomedicine  
Purpose-To harmonize data acquisition and post-processing of single voxel proton magnetic resonance spectroscopy ( 1 H-MRS) at 7 Tesla (7T), and to determine metabolite concentrations, accuracy and reproducibility of metabolite levels in the adult human brain. Experimental-This study was performed in compliance with local Institutional Human Ethics Committees. The same seven subjects were each examined twice using four different 7T MRsystems from two different vendors using an identical
more » ... ER spectroscopy sequence. Neurochemical profiles were obtained from the posterior cingulate cortex (GM) and the corona radiata (WM). Spectra were analyzed with LCModel, and sources of variation in concentrations ('subject', 'institute' & 'random') were identified with a variance components analysis. Results-Concentrations of 10-11 metabolites, which were corrected for T1, T2, Magnetization Transfer-effects and partial volume effects, were obtained with mean Cramér-Rao Lower Bounds below 20%. Data variances and mean concentrations in GM and WM were comparable for all institutions. The primary source of variance for glutamate, myo-inositol, scyllo-inositol, total creatine and total choline was between-subjects. Variance sources for all other metabolites were associated to within-subject and system noise, except for total N-acetylaspartate, glutamine and glutathione, which related to differences in signal-to-noise and in shimming performance between vendors. Conclusion-After multi-center harmonization of acquisition and post-processing protocols, metabolite concentrations and size and sources of their variations were established for neurochemical profiles in the healthy brain at 7T, which can be used as guidance in future studies
doi:10.1002/nbm.3252 pmid:25581510 pmcid:PMC4339538 fatcat:isj3y2yoabg2pb6ppvpj7p6m4a