Intra‐ and inter‐site reproducibility of human brain single‐voxel proton MRS at 3 T. (19th March 2019)

• Record Type: Journal Article
• Authors: Graf, Carina; MacMillan, Erin L.; Fu, Eric; Harris, Trudy; Traboulsee, Anthony; Vavasour, Irene M.; MacKay, Alex L.; Mädler, Burkhard; Li, David K.B.; Laule, Cornelia
• Is Part Of: NMR in biomedicine. Volume 32:Number 6(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-03-19
• Subjects: 3 T -- MRS -- multi‐site -- PRESS -- reproducibility -- single voxel; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.4083
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : Introduction: Clinical trials that involve participants from multiple sites necessitate standardized and reliable quantitative MRI outcomes to detect significant group differences over time. Metabolite concentrations measured by proton MRS ( 1 H‐MRS) provide valuable information about in vivo metabolism of the central nervous system, but can vary based on the acquisition and quantitation methods used by different MR sites. Therefore, we investigated the intra‐ and inter‐site reproducibility of metabolite concentrations measured by 1 H‐MRS on MRI scanners from a single manufacturer across six sites. Methods: Five healthy controls were scanned twice within 24 h at six participating 3 T MR sites with large single‐voxel PRESS ( T E/ T R/NSA = 36 ms/4000 ms/56) and anatomical images for voxel positioning and correction of partial volume relaxation. Absolute metabolite concentrations were calculated relative to the T 1 and T 2 relaxation corrected signal from water. Intra‐ and inter‐site reproducibility was assessed using Bland–Altman plots and intra‐ and inter‐site coefficient of variation (CoV) as well as intra‐ and inter‐site intra‐class correlation coefficient. Results: The median intra‐site CoVs for the five major metabolite concentrations ([NAA], [tCr], [Glu], [tCho] and [Ins]) were between 2.5 and 5.3%. Inter‐site CoVs were also low, with the median CoVs for all metabolites between 3.7 and 6.4%. Metabolite concentrations were robust to small inconsistencies in voxel placement and site was not the driving factor in the variance of the measurement of any metabolite concentration. Between‐subject differences accounted for the majority of the concentration variability for creatine, choline and myo ‐inositol (42–65% of the variance). Conclusion: A large single‐voxel 1 H‐MRS acquisition from a single manufacturer's MRI scanner is highly reproducible and reliable for multi‐site clinical trials. Abstract : In vivo 1 H‐MRS is a useful tool for assessing brain pathology and is used in multi‐centre clinical trials. To expand the usefulness of 1 H‐MRS in multi‐centre trials, this work examined the reproducibility of metabolites measured with a large single‐voxel 1 H‐MRS PRESS at six sites with the same vendor. The small intra‐ and inter‐site coefficients of variation (CoV < 7%) provide evidence that 1 H‐MRS can quantify metabolite concentrations reproducibly across multiple MR sites, supporting its application in future multi‐centre clinical trials.