Investigating GABA concentrations measured with macromolecule suppressed and unsuppressed MEGA-PRESS MR spectroscopy and their relationship with BOLD responses in the occipital cortex

Niall-William Duncan, Jianfeng Zhang, Georg Northoff, Xuchu Weng

Research output: Contribution to journalArticle

Abstract

Background: A combination of magnetic resonance spectroscopy (MRS) and functional (f)MRI is a promising method for studying brain activity. Negative results have, however, produced uncertainty as to the validity of the approach. Using a MEGA-PRESS sequence adapted to suppress the macromolecule signal (GABA–) has been suggested as a key methodological improvement, but there is some doubt as to the relationship between such estimates and those from the standard sequence (GABA+), making interpretation difficult. Purpose: To investigate the relationship between GABA+ and GABA– estimates from the posterior cingulate and occipital cortices. The second aim was to test for a correlation between occipital GABA and blood oxygenation level-dependent (BOLD) responses in the visual cortex to establish which of the two MEGA-PRESS sequences was more related to the functional responses. Study Type: Prospective. Subjects: Thirty-one healthy participants. Field Strength/Sequence: 3T/single-voxel 1 H-MRS and gradient-echo echo planar imaging (EPI). Assessment: GABA estimates were made using the Gannet toolbox. fMRI data were analyzed with FSL and Python scripts. Statistical Test: Relationships between different variables were tested with Pearson's correlation. Results: GABA+ and GABA– concentrations were found to be correlated in both regions (r = 0.52, 95% confidence interval [CI] = 0.35 0.66, p FDR = 0.002). No relationship was found between either the GABA+ or the GABA– concentrations and the amplitude of the BOLD response in the occipital cortex (GABA+, r = –0.14, p FDR > 0.1; GABA–, r = –0.29, p FDR >0.1). However, adding these results to those of prior studies in a meta-analysis of correlation coefficients did provide overall support for a negative correlation between GABA and BOLD response amplitudes (r = –0.39, 95% CI = –0.15–0.64). Data Conclusion: The current findings highlight potential methodological issues that continue to interfere with relating MRS GABA estimates with fMRI responses but, taken in sum, provide support for this general approach. Level of Evidence: 1. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2019.

Original languageEnglish
JournalJournal of Magnetic Resonance Imaging
DOIs
Publication statusPublished - Mar 15 2019

Fingerprint

Occipital Lobe
gamma-Aminobutyric Acid
Magnetic Resonance Spectroscopy
Magnetic Resonance Imaging
Boidae
Confidence Intervals
Echo-Planar Imaging
Gyrus Cinguli
Visual Cortex
Uncertainty

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

@article{5853205049cb44e083d7e25efea1377c,
title = "Investigating GABA concentrations measured with macromolecule suppressed and unsuppressed MEGA-PRESS MR spectroscopy and their relationship with BOLD responses in the occipital cortex",
abstract = "Background: A combination of magnetic resonance spectroscopy (MRS) and functional (f)MRI is a promising method for studying brain activity. Negative results have, however, produced uncertainty as to the validity of the approach. Using a MEGA-PRESS sequence adapted to suppress the macromolecule signal (GABA–) has been suggested as a key methodological improvement, but there is some doubt as to the relationship between such estimates and those from the standard sequence (GABA+), making interpretation difficult. Purpose: To investigate the relationship between GABA+ and GABA– estimates from the posterior cingulate and occipital cortices. The second aim was to test for a correlation between occipital GABA and blood oxygenation level-dependent (BOLD) responses in the visual cortex to establish which of the two MEGA-PRESS sequences was more related to the functional responses. Study Type: Prospective. Subjects: Thirty-one healthy participants. Field Strength/Sequence: 3T/single-voxel 1 H-MRS and gradient-echo echo planar imaging (EPI). Assessment: GABA estimates were made using the Gannet toolbox. fMRI data were analyzed with FSL and Python scripts. Statistical Test: Relationships between different variables were tested with Pearson's correlation. Results: GABA+ and GABA– concentrations were found to be correlated in both regions (r = 0.52, 95{\%} confidence interval [CI] = 0.35 0.66, p FDR = 0.002). No relationship was found between either the GABA+ or the GABA– concentrations and the amplitude of the BOLD response in the occipital cortex (GABA+, r = –0.14, p FDR > 0.1; GABA–, r = –0.29, p FDR >0.1). However, adding these results to those of prior studies in a meta-analysis of correlation coefficients did provide overall support for a negative correlation between GABA and BOLD response amplitudes (r = –0.39, 95{\%} CI = –0.15–0.64). Data Conclusion: The current findings highlight potential methodological issues that continue to interfere with relating MRS GABA estimates with fMRI responses but, taken in sum, provide support for this general approach. Level of Evidence: 1. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2019.",
author = "Niall-William Duncan and Jianfeng Zhang and Georg Northoff and Xuchu Weng",
year = "2019",
month = "3",
day = "15",
doi = "10.1002/jmri.26706",
language = "English",
journal = "Journal of Magnetic Resonance Imaging",
issn = "1053-1807",
publisher = "John Wiley and Sons Inc.",

}

TY - JOUR

T1 - Investigating GABA concentrations measured with macromolecule suppressed and unsuppressed MEGA-PRESS MR spectroscopy and their relationship with BOLD responses in the occipital cortex

AU - Duncan, Niall-William

AU - Zhang, Jianfeng

AU - Northoff, Georg

AU - Weng, Xuchu

PY - 2019/3/15

Y1 - 2019/3/15

N2 - Background: A combination of magnetic resonance spectroscopy (MRS) and functional (f)MRI is a promising method for studying brain activity. Negative results have, however, produced uncertainty as to the validity of the approach. Using a MEGA-PRESS sequence adapted to suppress the macromolecule signal (GABA–) has been suggested as a key methodological improvement, but there is some doubt as to the relationship between such estimates and those from the standard sequence (GABA+), making interpretation difficult. Purpose: To investigate the relationship between GABA+ and GABA– estimates from the posterior cingulate and occipital cortices. The second aim was to test for a correlation between occipital GABA and blood oxygenation level-dependent (BOLD) responses in the visual cortex to establish which of the two MEGA-PRESS sequences was more related to the functional responses. Study Type: Prospective. Subjects: Thirty-one healthy participants. Field Strength/Sequence: 3T/single-voxel 1 H-MRS and gradient-echo echo planar imaging (EPI). Assessment: GABA estimates were made using the Gannet toolbox. fMRI data were analyzed with FSL and Python scripts. Statistical Test: Relationships between different variables were tested with Pearson's correlation. Results: GABA+ and GABA– concentrations were found to be correlated in both regions (r = 0.52, 95% confidence interval [CI] = 0.35 0.66, p FDR = 0.002). No relationship was found between either the GABA+ or the GABA– concentrations and the amplitude of the BOLD response in the occipital cortex (GABA+, r = –0.14, p FDR > 0.1; GABA–, r = –0.29, p FDR >0.1). However, adding these results to those of prior studies in a meta-analysis of correlation coefficients did provide overall support for a negative correlation between GABA and BOLD response amplitudes (r = –0.39, 95% CI = –0.15–0.64). Data Conclusion: The current findings highlight potential methodological issues that continue to interfere with relating MRS GABA estimates with fMRI responses but, taken in sum, provide support for this general approach. Level of Evidence: 1. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2019.

AB - Background: A combination of magnetic resonance spectroscopy (MRS) and functional (f)MRI is a promising method for studying brain activity. Negative results have, however, produced uncertainty as to the validity of the approach. Using a MEGA-PRESS sequence adapted to suppress the macromolecule signal (GABA–) has been suggested as a key methodological improvement, but there is some doubt as to the relationship between such estimates and those from the standard sequence (GABA+), making interpretation difficult. Purpose: To investigate the relationship between GABA+ and GABA– estimates from the posterior cingulate and occipital cortices. The second aim was to test for a correlation between occipital GABA and blood oxygenation level-dependent (BOLD) responses in the visual cortex to establish which of the two MEGA-PRESS sequences was more related to the functional responses. Study Type: Prospective. Subjects: Thirty-one healthy participants. Field Strength/Sequence: 3T/single-voxel 1 H-MRS and gradient-echo echo planar imaging (EPI). Assessment: GABA estimates were made using the Gannet toolbox. fMRI data were analyzed with FSL and Python scripts. Statistical Test: Relationships between different variables were tested with Pearson's correlation. Results: GABA+ and GABA– concentrations were found to be correlated in both regions (r = 0.52, 95% confidence interval [CI] = 0.35 0.66, p FDR = 0.002). No relationship was found between either the GABA+ or the GABA– concentrations and the amplitude of the BOLD response in the occipital cortex (GABA+, r = –0.14, p FDR > 0.1; GABA–, r = –0.29, p FDR >0.1). However, adding these results to those of prior studies in a meta-analysis of correlation coefficients did provide overall support for a negative correlation between GABA and BOLD response amplitudes (r = –0.39, 95% CI = –0.15–0.64). Data Conclusion: The current findings highlight potential methodological issues that continue to interfere with relating MRS GABA estimates with fMRI responses but, taken in sum, provide support for this general approach. Level of Evidence: 1. Technical Efficacy: Stage 1. J. Magn. Reson. Imaging 2019.

UR - http://www.scopus.com/inward/record.url?scp=85062982632&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062982632&partnerID=8YFLogxK

U2 - 10.1002/jmri.26706

DO - 10.1002/jmri.26706

M3 - Article

JO - Journal of Magnetic Resonance Imaging

JF - Journal of Magnetic Resonance Imaging

SN - 1053-1807

ER -