| Literature DB >> 30840905 |
Mark Mikkelsen1, Daniel L Rimbault2, Peter B Barker3, Pallab K Bhattacharyya4, Maiken K Brix5, Pieter F Buur6, Kim M Cecil7, Kimberly L Chan8, David Y-T Chen9, Alexander R Craven10, Koen Cuypers11, Michael Dacko12, Niall W Duncan13, Ulrike Dydak14, David A Edmondson14, Gabriele Ende15, Lars Ersland16, Megan A Forbes17, Fei Gao18, Ian Greenhouse19, Ashley D Harris20, Naying He21, Stefanie Heba22, Nigel Hoggard23, Tun-Wei Hsu24, Jacobus F A Jansen25, Alayar Kangarlu26, Thomas Lange12, R Marc Lebel27, Yan Li21, Chien-Yuan E Lin28, Jy-Kang Liou24, Jiing-Feng Lirng24, Feng Liu29, Joanna R Long30, Ruoyun Ma31, Celine Maes32, Marta Moreno-Ortega33, Scott O Murray34, Sean Noah35, Ralph Noeske36, Michael D Noseworthy37, Georg Oeltzschner3, Eric C Porges17, James J Prisciandaro38, Nicolaas A J Puts3, Timothy P L Roberts39, Markus Sack15, Napapon Sailasuta40, Muhammad G Saleh3, Michael-Paul Schallmo41, Nicholas Simard42, Diederick Stoffers6, Stephan P Swinnen43, Martin Tegenthoff22, Peter Truong44, Guangbin Wang18, Iain D Wilkinson23, Hans-Jörg Wittsack45, Adam J Woods17, Hongmin Xu21, Fuhua Yan21, Chencheng Zhang46, Vadim Zipunnikov47, Helge J Zöllner48, Richard A E Edden3.
Abstract
Accurate and reliable quantification of brain metabolites measured in vivo using 1H magnetic resonance spectroscopy (MRS) is a topic of continued interest. Aside from differences in the basic approach to quantification, the quantification of metabolite data acquired at different sites and on different platforms poses an additional methodological challenge. In this study, spectrally edited γ-aminobutyric acid (GABA) MRS data were analyzed and GABA levels were quantified relative to an internal tissue water reference. Data from 284 volunteers scanned across 25 research sites were collected using GABA+ (GABA + co-edited macromolecules (MM)) and MM-suppressed GABA editing. The unsuppressed water signal from the volume of interest was acquired for concentration referencing. Whole-brain T1-weighted structural images were acquired and segmented to determine gray matter, white matter and cerebrospinal fluid voxel tissue fractions. Water-referenced GABA measurements were fully corrected for tissue-dependent signal relaxation and water visibility effects. The cohort-wide coefficient of variation was 17% for the GABA + data and 29% for the MM-suppressed GABA data. The mean within-site coefficient of variation was 10% for the GABA + data and 19% for the MM-suppressed GABA data. Vendor differences contributed 53% to the total variance in the GABA + data, while the remaining variance was attributed to site- (11%) and participant-level (36%) effects. For the MM-suppressed data, 54% of the variance was attributed to site differences, while the remaining 46% was attributed to participant differences. Results from an exploratory analysis suggested that the vendor differences were related to the unsuppressed water signal acquisition. Discounting the observed vendor-specific effects, water-referenced GABA measurements exhibit similar levels of variance to creatine-referenced GABA measurements. It is concluded that quantification using internal tissue water referencing is a viable and reliable method for the quantification of in vivo GABA levels.Entities:
Keywords: Editing; GABA; MEGA-PRESS; MRS; Quantification; Tissue correction
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Year: 2019 PMID： 30840905 PMCID： PMC6818968 DOI： 10.1016/j.neuroimage.2019.02.059
Source DB: PubMed Journal: Neuroimage ISSN： 1053-8119 Impact factor: 6.556