Gannet: A batch‐processing tool for the quantitative analysis of gamma‐aminobutyric acid–edited MR spectroscopy spectra

Edden, Richard A.E.; Puts, Nicolaas A.J.; Harris, Ashley D.; Barker, Peter B.; Evans, John

doi:10.1002/jmri.24478

Cited by 544 publications

(506 citation statements)

References 43 publications

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“…This voxel mask was then applied to the SPM segmentation to determine the voxel GM, WM and CSF fractions. This functionality is now available within the Gannet 2.0 toolbox (20) as Gannet Co Register and Gannet Segment. For the comparison of segmentation tools, a binary mask was similarly reconstructed using SVMask (Michael Schär, Philips Medical Systems) and applied to the segmentation results from FSL.…”

Section: Methodsmentioning

confidence: 99%

Tissue correction for GABA‐edited MRS: Considerations of voxel composition, tissue segmentation, and tissue relaxations

Harris

Puts

Edden

2015

Magnetic Resonance Imaging

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265

292

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Purpose To develop a tissue correction for GABA-edited MRS that appropriately addresses differences in voxel gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) fractions. Methods Simulations compared the performance of tissue correction approaches. Corrections were then applied to in vivo data from sixteen healthy volunteers, acquired at 3T. GM, WM and CSF fractions were determined from T1-weighted images. Corrections for CSF content, GM/WM GABA content, and water relaxation of the three compartments are combined into a single, fully corrected measurement. Results Simulations show that CSF correction increases the dependence of GABA measurements on GM/WM fraction, by an amount equal to the fraction of CSF. Furthermore, GM correction substantially (and non-linearly) increases the dependence of GABA measurements on GM/WM fraction, for example, by a factor of over four when the voxel GM tissue fraction is 50%. At this tissue fraction, GABA is over estimated by a factor of 1.5. For the in vivo data, correcting for voxel composition increased measured GABA values (p<0.001 for all regions), but did not reduce inter-subject variance (p>0.5 for all regions). Corrected GABA values differ significantly based on the segmentation procedure used (p<0.0001) and tissue parameter assumptions made (p<0.0001). Conclusion We introduce a comprehensive tissue correction factor that adjusts GABA measurements to correct for different voxel compositions of GM, WM, and CSF.

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Section: Methodsmentioning

confidence: 99%

Tissue correction for GABA‐edited MRS: Considerations of voxel composition, tissue segmentation, and tissue relaxations

Harris

Puts

Edden

2015

Magnetic Resonance Imaging

Self Cite

265

292

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“…GANNET, a MATLAB-based tool (Edden et al, 2014), was used to assess GABAþ/tCr and Glx/tCr in each spectrum using default parameters, including frequency and phase correction of timeresolved data using spectral registration (Near et al, 2015). Glx signal was quantified from the 3.75 ppm as pseudo-doublet peaks in the GANNET-edited spectrum.…”

Section: H-mrs Analysismentioning

confidence: 99%

GABA content within the ventromedial prefrontal cortex is related to trait anxiety

Pizzi

Padulo

Brancucci

et al. 2015

Soc Cogn Affect Neurosci

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The ventromedial prefrontal cortex (vmPFC) plays a key role in emotion processing and regulation. vmPFC dysfunction may lead to disinhibition of amygdala causing high anxiety levels. c-Aminobutyric acid (GABA) inter-neurons within vmPFC shape the information flow to amygdala. Thus, we hypothesize that GABA content within vmPFC could be relevant to trait anxiety. Forty-three healthy volunteers aged between 20 and 88 years were assessed for trait anxiety with the Subscale-2 of the State-Trait-Anxiety Inventory (STAI-Y2) and were studied with proton magnetic resonance spectroscopy to investigate GABA and Glx (glutamateþglutamine) contents within vmPFC. Total creatine (tCr) was used as internal reference. Partial correlations assessed the association between metabolite levels and STAI-Y2 scores, removing the effect of possible nuisance factors including age, educational level, volumes of gray matter and white matter within magnetic resonance spectroscopy voxel. We observed a positive relationship between GABA/tCr and STAI-Y2 scores. No significant relationships were found between Glx/tCr and STAI-Y2 and between tCr/water and STAI-Y2. No differences were found between males and females as regards to age, STAI-Y2, GABA/tCr, Glx/tCr, tCr/water, gray matter and white matter volumes. We suggest a close relationship between GABA content within vmPFC and trait anxiety providing new insights in the physiology of emotional brain.

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“…The Gannet GABA+ fit error is calculated as a percentage of the SD of the residual (raw data minus fit) divided by GABA+ peak amplitude 48 . Calculation of the ProFit CRLB has been described elsewhere 35 .…”

Section: Methodsmentioning

confidence: 99%

Two-Dimensional Proton Magnetic Resonance Spectroscopy versus J-Editing for GABA Quantification in Human Brain: Insights from a GABA-Aminotransferase Inhibitor Study

Prescot

Prisciandaro

Miller

et al. 2018

Sci Rep

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Metabolite-specific, scalar spin-spin coupling constant (J)-editing 1H MRS methods have become gold-standard for measuring brain γ-amino butyric acid (GABA) levels in human brain. Localized, two-dimensional (2D) 1H MRS technology offers an attractive alternative as it significantly alleviates the problem of severe metabolite signal overlap associated with standard 1D MRS and retains spectroscopic information for all MRS-detectable species. However, for metabolites found at low concentration, a direct, in vivo, comprehensive methods comparison is challenging and has not been reported to date. Here, we document an assessment of comparability between 2D 1H MRS and J-editing methods for measuring GABA in human brain. This clinical study is unique in that it involved chronic administration a GABA-amino transferase (AT) inhibitor (CPP-115), which induces substantial increases in brain GABA concentration, with normalization after washout. We report a qualitative and quantitative comparison between these two measurement techniques. In general, GABA concentration changes detected using J-editing were closely mirrored by the 2D 1H MRS time courses. The data presented are particularly encouraging considering recent 2D 1H MRS methodological advances are continuing to improve temporal resolution and spatial coverage for achieving whole-brain, multi-metabolite mapping.

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Gannet: A batch‐processing tool for the quantitative analysis of gamma‐aminobutyric acid–edited MR spectroscopy spectra

Cited by 544 publications

References 43 publications

Tissue correction for GABA‐edited MRS: Considerations of voxel composition, tissue segmentation, and tissue relaxations

Tissue correction for GABA‐edited MRS: Considerations of voxel composition, tissue segmentation, and tissue relaxations

GABA content within the ventromedial prefrontal cortex is related to trait anxiety

Two-Dimensional Proton Magnetic Resonance Spectroscopy versus J-Editing for GABA Quantification in Human Brain: Insights from a GABA-Aminotransferase Inhibitor Study

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