@article{96041a93f92a439ba99f6138875e29a2,
title = "In silico GABA+ MEGA-PRESS: Effects of signal-to-noise ratio and linewidth on modeling the 3 ppm GABA+ resonance",
abstract = "To investigate the GABA+ modeling accuracy of MEGA-PRESS GABA+-edited MRS data with various spectral quality scenarios, the influence of varying signal-to-noise ratio (SNR) and linewidth on the model estimates was quantified. MEGA-PRESS data from 46 volunteers were averaged to generate a template MEGA-PRESS spectrum, which was modeled and quantified to generate a GABA+ level ground truth. This spectrum was then manipulated by adding 427 combinations of varying artificial noise levels and line broadening, mimicking variations in GABA+ SNR and B0 homogeneity. GABA+ modeling and quantification was performed with 100 simulated spectra per condition using automated routines in both Gannet 3.0 and Tarquin. The GABA+ estimation error was calculated as the relative deviation to the quantified GABA+ ground truth levels to assess the accuracy of GABA+ modeling. Finally, the accordance between the simulations and different in vivo scenarios was assessed. The GABA+ estimation error was smaller than 5% for all GABA+ SNR values with creatine linewidths lower than 9.7 Hz in Gannet 3.0 or unequal 10.6 Hz in Tarquin. The standard deviation of the GABA+ amplitude over 100 spectra per condition varied between 3.1 and 17% (Gannet 3.0) and between 1 and 11% (Tarquin) over the in vivo relevant GABA+ SNR range between 2.6 and 3.5. GABA+ edited studies might be realized for voxels with low GABA+ SNR at the cost of higher group-level variance. The accuracy of GABA+ modeling had no relation to commonly used quality metrics. The Tarquin algorithm was found to be more robust against linewidth changes than the fitting algorithm in Gannet.",
keywords = "GABA+, MEGA-PRESS, MRS, SNR, fitting accuracy, linewidth, modelling, simulations",
author = "Z{\"o}llner, {Helge J{\"o}rn} and Georg Oeltzschner and Alfons Schnitzler and Wittsack, {Hans J{\"o}rg}",
note = "Funding Information: The authors would like to express their thanks to Erika R{\"a}disch (Department of Diagnostic and Interventional Radiology, University Hospital D{\"u}sseldorf) for support with MR measurements. This work was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft Sonderforschungsbereich (SFB) 974 Project B07). GO is receiving salary support from NIH grants K99AG062230, R01EB016089, and R21AG060245. In addition, we thank Dr Markus Butz (Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University D{\"u}sseldorf, Germany) for critical manuscript revision. HJZ would like to thank the Deutscher Akademischer Austauschdienst (DAAD) for a conference travel grant to present parts of the work at the ISMRM 2018. The funding sources had no involvement in the study design, collection, analysis, or interpretation of the presented data. Funding Information: The authors would like to express their thanks to Erika R?disch (Department of Diagnostic and Interventional Radiology, University Hospital D?sseldorf) for support with MR measurements. This work was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft Sonderforschungsbereich (SFB) 974 Project B07). GO is receiving salary support from NIH grants K99AG062230, R01EB016089, and R21AG060245. In addition, we thank Dr Markus Butz (Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University D?sseldorf, Germany) for critical manuscript revision. HJZ would like to thank the Deutscher Akademischer Austauschdienst (DAAD) for a conference travel grant to present parts of the work at the ISMRM 2018. The funding sources had no involvement in the study design, collection, analysis, or interpretation of the presented data. Open Access funding enabled and organized by Projekt DEAL. Publisher Copyright: {\textcopyright} 2020 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd",
year = "2021",
month = jan,
doi = "10.1002/nbm.4410",
language = "English (US)",
volume = "34",
journal = "NMR in biomedicine",
issn = "0952-3480",
publisher = "John Wiley and Sons Ltd",
number = "1",
}