1
|
Siegel-Ramsay JE, Romaniuk L, Whalley HC, Roberts N, Branigan H, Stanfield AC, Lawrie SM, Dauvermann MR. Glutamate and functional connectivity - support for the excitatory-inhibitory imbalance hypothesis in autism spectrum disorders. Psychiatry Res Neuroimaging 2021; 313:111302. [PMID: 34030047 DOI: 10.1016/j.pscychresns.2021.111302] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 04/30/2021] [Accepted: 05/07/2021] [Indexed: 12/24/2022]
Abstract
It has been proposed that the Glutamate (Glu) system is implicated in autism spectrum disorders (ASD) via an imbalance between excitatory and inhibitory brain circuits, which impacts on brain function. Here, we investigated the excitatory-inhibitory imbalance theory by measuring Glu-concentrations and the relationship with resting-state function. Nineteen adult males with ASD and 19 age and sex-matched healthy controls (HC) (23 - 58 years) underwent Proton Magnetic Resonance Spectroscopy of the dorsal anterior cingulate cortex (dACC) and resting-state functional Magnetic Resonance Imaging (fMRI). Glu and Glx concentrations were compared between groups. Seed-based functional connectivity was analyzed with a priori seeds of the right and left dACC. Finally, metabolite concentrations were related to functional connectivity coefficients and compared between both groups. Individuals with ASD showed significantly negative associations between increased Glx concentrations and reduced functional connectivity between the dACC and insular, limbic and parietal regions. In contrast, HC displayed a positive relationship between the same metabolite and connectivity measures. We provided new evidence to support the excitatory-inhibitory imbalance theory, where excitatory Glx concentrations were related to functional dysconnectivity in ASD. Future research is needed to investigate large-scale functional networks in association with both excitatory and inhibitory metabolites in subpopulations of ASD.
Collapse
Affiliation(s)
- Jennifer E Siegel-Ramsay
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom; Department of Psychiatry and Behavioral Science, University of Texas, Austin, United States
| | - Liana Romaniuk
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom
| | - Heather C Whalley
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom
| | - Neil Roberts
- Centre for Reproductive Health (CRH), School of Clinical Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Holly Branigan
- School of Psychology, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew C Stanfield
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom; Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen M Lawrie
- Division of Psychiatry, University of Edinburgh, Edinburgh, United Kingdom
| | - Maria R Dauvermann
- Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, United Kingdom; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, United States.
| |
Collapse
|
2
|
Choi IY, Andronesi OC, Barker P, Bogner W, Edden RAE, Kaiser LG, Lee P, Marjańska M, Terpstra M, de Graaf RA. Spectral editing in 1 H magnetic resonance spectroscopy: Experts' consensus recommendations. NMR IN BIOMEDICINE 2021; 34:e4411. [PMID: 32946145 PMCID: PMC8557623 DOI: 10.1002/nbm.4411] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 05/08/2023]
Abstract
Spectral editing in in vivo 1 H-MRS provides an effective means to measure low-concentration metabolite signals that cannot be reliably measured by conventional MRS techniques due to signal overlap, for example, γ-aminobutyric acid, glutathione and D-2-hydroxyglutarate. Spectral editing strategies utilize known J-coupling relationships within the metabolite of interest to discriminate their resonances from overlying signals. This consensus recommendation paper provides a brief overview of commonly used homonuclear editing techniques and considerations for data acquisition, processing and quantification. Also, we have listed the experts' recommendations for minimum requirements to achieve adequate spectral editing and reliable quantification. These include selecting the right editing sequence, dealing with frequency drift, handling unwanted coedited resonances, spectral fitting of edited spectra, setting up multicenter clinical trials and recommending sequence parameters to be reported in publications.
Collapse
Affiliation(s)
- In-Young Choi
- Department of Neurology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, Kansas
| | - Ovidiu C Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Peter Barker
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, F. M. Kirby Center for Functional MRI, Kennedy Krieger Institute, Baltimore, Maryland
| | - Wolfgang Bogner
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, F. M. Kirby Center for Functional MRI, Kennedy Krieger Institute, Baltimore, Maryland
| | - Lana G Kaiser
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, California
| | - Phil Lee
- Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, Kansas
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota
| | - Melissa Terpstra
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota
| | - Robin A de Graaf
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
| |
Collapse
|
3
|
Hong D, Rohani Rankouhi S, Thielen JW, van Asten JJA, Norris DG. A comparison of sLASER and MEGA-sLASER using simultaneous interleaved acquisition for measuring GABA in the human brain at 7T. PLoS One 2019; 14:e0223702. [PMID: 31603925 PMCID: PMC6788718 DOI: 10.1371/journal.pone.0223702] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 09/27/2019] [Indexed: 12/19/2022] Open
Abstract
γ-Aminobutyric acid (GABA), the major inhibitory neurotransmitter, is challenging to measure using proton spectroscopy due to its relatively low concentration, J-coupling and overlapping signals from other metabolites. Currently, the prevalent methods for detecting GABA at ultrahigh field strengths (≥ 7 T) are GABA-editing and model fitting of non-editing single voxel spectra. These two acquisition approaches have their own advantages: the GABA editing approach directly measures the GABA resonance at 3 ppm, whereas the fitting approach on the non-editing spectrum allows the detection of multiple metabolites, and has an SNR advantage over longer echo time (TE) acquisitions. This study aims to compare these approaches for estimating GABA at 7 T. We use an interleaved sequence of semi-LASER (sLASER: TE = 38 ms) and MEGA-sLASER (TE = 80 ms). This simultaneous interleaved acquisition minimizes the differential effect of extraneous factors, and enables an accurate comparison of the two acquisition methods. Spectra were acquired with an 8 ml isotropic voxel at six different brain regions: anterior-cingulate cortex, dorsolateral-prefrontal cortex, motor cortex, occipital cortex, posterior cingulate cortex, and precuneus. Spectral fitting with LCModel quantified the GABA to total Cr (tCr: Creatine + Phosphocreatine) concentration ratio. After correcting the T2 relaxation time variation, GABA/tCr ratios were similar between the two acquisition approaches. GABA editing showed smaller spectral fitting error according to Cramér-Rao lower bound than the sLASER approach for all regions examined. We conclude that both acquisition methods show similar accuracy but the precision of the MEGA-editing approach is higher for GABA measurement. In addition, the 2.28 ppm GABA resonance was found to be important for estimating GABA concentration without macromolecule contamination in the GABA-edited acquisition, when utilizing spectral fitting with LCModel.
Collapse
Affiliation(s)
- Donghyun Hong
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
| | | | - Jan-Willem Thielen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Department for Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany
| | - Jack J. A. van Asten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - David G. Norris
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Essen, Germany
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, Netherlands
| |
Collapse
|
4
|
Landheer K, Schulte RF, Treacy MS, Swanberg KM, Juchem C. Theoretical description of modern1H in Vivo magnetic resonance spectroscopic pulse sequences. J Magn Reson Imaging 2019; 51:1008-1029. [DOI: 10.1002/jmri.26846] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 01/20/2023] Open
Affiliation(s)
- Karl Landheer
- Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science New York New York USA
| | | | - Michael S. Treacy
- Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science New York New York USA
| | - Kelley M. Swanberg
- Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science New York New York USA
| | - Christoph Juchem
- Biomedical Engineering, Columbia University Fu Foundation School of Engineering and Applied Science New York New York USA
- Radiology, Columbia University College of Physicians and Surgeons New York New York USA
| |
Collapse
|
5
|
Prescot AP, Prisciandaro JJ, Miller SR, Ingenito G, Kondo DG, Renshaw PF. Two-Dimensional Proton Magnetic Resonance Spectroscopy versus J-Editing for GABA Quantification in Human Brain: Insights from a GABA-Aminotransferase Inhibitor Study. Sci Rep 2018; 8:13200. [PMID: 30181656 PMCID: PMC6123452 DOI: 10.1038/s41598-018-31591-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 08/22/2018] [Indexed: 11/25/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- Andrew P Prescot
- Department of Radiology and Imaging Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA.
| | - James J Prisciandaro
- Department of Psychiatry and Behavioral Sciences, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | | | | | - Douglas G Kondo
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, USA.,Rocky Mountain Mental Illness Research, Education, and Clinical Center (MIRECC), Department of Veterans Affairs Medical Center, Salt Lake City, UT, USA
| | - Perry F Renshaw
- Department of Psychiatry, University of Utah School of Medicine, Salt Lake City, UT, USA.,Rocky Mountain Mental Illness Research, Education, and Clinical Center (MIRECC), Department of Veterans Affairs Medical Center, Salt Lake City, UT, USA
| |
Collapse
|
6
|
Shungu DC, Mao X, Gonzales R, Soones TN, Dyke JP, van der Veen JW, Kegeles LS. Brain γ-aminobutyric acid (GABA) detection in vivo with the J-editing (1) H MRS technique: a comprehensive methodological evaluation of sensitivity enhancement, macromolecule contamination and test-retest reliability. NMR IN BIOMEDICINE 2016; 29:932-42. [PMID: 27173449 PMCID: PMC4909570 DOI: 10.1002/nbm.3539] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 03/17/2016] [Accepted: 03/21/2016] [Indexed: 05/21/2023]
Abstract
Abnormalities in brain γ-aminobutyric acid (GABA) have been implicated in various neuropsychiatric and neurological disorders. However, in vivo GABA detection by (1) H MRS presents significant challenges arising from the low brain concentration, overlap by much stronger resonances and contamination by mobile macromolecule (MM) signals. This study addresses these impediments to reliable brain GABA detection with the J-editing difference technique on a 3-T MR system in healthy human subjects by: (i) assessing the sensitivity gains attainable with an eight-channel phased-array head coil; (ii) determining the magnitude and anatomic variation of the contamination of GABA by MM; and (iii) estimating the test-retest reliability of the measurement of GABA with this method. Sensitivity gains and test-retest reliability were examined in the dorsolateral prefrontal cortex (DLPFC), whereas MM levels were compared across three cortical regions: DLPFC, the medial prefrontal cortex (MPFC) and the occipital cortex (OCC). A three-fold higher GABA detection sensitivity was attained with the eight-channel head coil compared with the standard single-channel head coil in DLPFC. Despite significant anatomical variation in GABA + MM and MM across the three brain regions (p < 0.05), the contribution of MM to GABA + MM was relatively stable across the three voxels, ranging from 41% to 49%, a non-significant regional variation (p = 0.58). The test-retest reliability of GABA measurement, expressed as either the ratio to voxel tissue water (W) or to total creatine, was found to be very high for both the single-channel coil and the eight-channel phased-array coil. For the eight-channel coil, for example, Pearson's correlation coefficient of test vs. retest for GABA/W was 0.98 (R(2) = 0.96, p = 0.0007), the percentage coefficient of variation (CV) was 1.25% and the intraclass correlation coefficient (ICC) was 0.98. Similar reliability was also found for the co-edited resonance of combined glutamate and glutamine (Glx) for both coils. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Dikoma C. Shungu
- Department of Radiology, Weill Cornell Medical College, New York, NY
| | - Xiangling Mao
- Department of Radiology, Weill Cornell Medical College, New York, NY
| | - Robyn Gonzales
- Department of Psychiatry, Columbia University, New York, NY
| | | | - Jonathan P. Dyke
- Department of Radiology, Weill Cornell Medical College, New York, NY
| | | | - Lawrence S. Kegeles
- Department of Psychiatry, Columbia University, New York, NY
- Department of Radiology, Columbia University, New York, NY
| |
Collapse
|
7
|
Andronesi OC, Rapalino O, Gerstner E, Chi A, Batchelor TT, Cahill DP, Sorensen AG, Rosen BR. Detection of oncogenic IDH1 mutations using magnetic resonance spectroscopy of 2-hydroxyglutarate. J Clin Invest 2013; 123:3659-63. [PMID: 23999439 DOI: 10.1172/jci67229] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The investigation of metabolic pathways disturbed in isocitrate dehydrogenase (IDH) mutant tumors revealed that the hallmark metabolic alteration is the production of D-2-hydroxyglutarate (D-2HG). The biological impact of D-2HG strongly suggests that high levels of this metabolite may play a central role in propagating downstream the effects of mutant IDH, leading to malignant transformation of cells. Hence, D-2HG may be an ideal biomarker for both diagnosing and monitoring treatment response targeting IDH mutations. Magnetic resonance spectroscopy (MRS) is well suited to the task of noninvasive D-2HG detection, and there has been much interest in developing such methods. Here, we review recent efforts to translate methodology using MRS to reliably measure in vivo D-2HG into clinical research.
Collapse
Affiliation(s)
- Ovidiu C Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Associations between prefrontal γ-aminobutyric acid concentration and the tryptophan hydroxylase isoform 2 gene, a panic disorder risk allele in women. Int J Neuropsychopharmacol 2013; 16:1707-17. [PMID: 23552096 PMCID: PMC4025920 DOI: 10.1017/s1461145713000254] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Associations between the central serotonergic and γ-aminobutyric acid (GABA) systems play key roles in the prefrontal cortical regulation of emotion and cognition and in the pathophysiology and pharmacotherapy of highly prevalent psychiatric disorders. The goal of this study was to test the effects of common variants of the tryptophan hydroxylase isoform 2 (TPH2) gene on GABA concentration in the prefrontal cortex (PFC) using magnetic resonance spectroscopy. In this study involving 64 individuals, we examined the associations between prefrontal cortical GABA concentration and 12 single nucleotide polymorphisms (SNPs) spanning the TPH2 gene, including rs4570625 (-703 G/T SNP), a potentially functional TPH2 polymorphism that has been associated with decreased TPH2 mRNA expression and panic disorder. Our results revealed a significant association between increased GABA concentration in the PFC and the T-allele frequencies of two TPH2 SNPs, namely rs4570625 (-703 G/T) and rs2129575 (p⩽0.0004) and the C-allele frequency of one TPH2 SNP, namely rs1386491 (p = 0.0003) in female subjects. We concluded that rs4570625 (-703 G/T), rs2129575 and rs1386491 play a significant role in GABAergic neurotransmission and may contribute to the sex-specific dysfunction of the GABAergic system in the PFC.
Collapse
|
9
|
Abstract
Brain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of psychiatric and neurological disorders and in the mechanisms of antidepressant pharmacotherapy. Psychiatric and neurological conditions have also been associated with reduced brain levels of N-acetyl-aspartate (NAA), which has been used as a putative marker of neural integrity. However, few studies have explored the relationship between BDNF polymorphisms and NAA levels directly. Here, we present data from a single-voxel proton magnetic resonance spectroscopy study of 64 individuals and explore the relationship between BDNF polymorphisms and prefrontal NAA level. Our results indicate an association between a single nucleotide polymorphism (SNP) within BDNF, known as rs1519480, and reduced NAA level (p = 0.023). NAA levels were further predicted by age and Asian ancestry. There was a significant rs1519480 × age interaction on NAA level (p = 0.031). Specifically, the effect of rs1519480 on NAA level became significant at age ⩾34.17 yr. NAA level decreased with advancing age for genotype TT (p = 0.001) but not for genotype CT (p = 0.82) or CC (p = 0.34). Additional in silico analysis of 142 post-mortem brain samples revealed an association between the same SNP and reduced BDNF mRNA expression in the prefrontal cortex. The rs1519480 SNP influences BDNF mRNA expression and has an impact on prefrontal NAA level over time. This genetic mechanism may contribute to inter-individual variation in cognitive performance seen during normal ageing, as well as contributing to the risk for developing psychiatric and neurological conditions.
Collapse
|
10
|
Choi IY, Lee P. Doubly selective multiple quantum chemical shift imaging and T(1) relaxation time measurement of glutathione (GSH) in the human brain in vivo. NMR IN BIOMEDICINE 2013; 26:28-34. [PMID: 22730142 PMCID: PMC3465620 DOI: 10.1002/nbm.2815] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Revised: 04/11/2012] [Accepted: 04/13/2012] [Indexed: 05/06/2023]
Abstract
Mapping of a major antioxidant, glutathione (GSH), was achieved in the human brain in vivo using a doubly-selective multiple quantum filtering based chemical shift imaging (CSI) of GSH at 3 T. Both in vivo and phantom tests in CSI and single voxel measurements were consistent with excellent suppression of overlapping signals from creatine, γ-Amino butyric acid (GABA) and macromolecules. GSH concentration in the fronto-parietal region was 1.20 ± 0.16 µmol/g (mean ± SD, n = 7). The longitudinal relaxation time (T(1) ) of GSH in the human brain was 397 ± 44 ms (mean ± SD, n = 5), which was substantially shorter than that of other metabolites. This GSH-CSI method permits us to address regional differences of GSH in the human brain under conditions where oxidative stress has been implicated, including multiple sclerosis, aging and neurodegenerative diseases.
Collapse
Affiliation(s)
- In-Young Choi
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | | |
Collapse
|
11
|
Kim H, Thompson RB, Allen PS. Enhancement of spectral editing efficacy of multiple quantum filters in in vivo proton magnetic resonance spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2012; 223:90-97. [PMID: 22975239 DOI: 10.1016/j.jmr.2012.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 07/12/2012] [Accepted: 07/24/2012] [Indexed: 06/01/2023]
Abstract
The performance of multiple quantum filters (MQFs) can be disappointing when the background signal also arises from coupled spins. Moreover, at 3.0 T and even higher fields the majority of the spin systems of key brain metabolites fall into the strong-coupling regime. In this manuscript we address comprehensively, the importance of the phase of the multiple quantum coherence-generating pulse (MQ-pulse) in the design of MQFs, using both product operator and numerical analysis, in both zero and double quantum filter designs. The theoretical analyses were experimentally validated with the examples of myo-inositol editing and the separation of glutamate from glutamine. The results demonstrate that the phase of the MQ-pulse per se provides an additional spectral discrimination mechanism based on the degree of coupling beyond the conventional level-of-coherence approach of MQFs. To obtain the best spectral discrimination of strongly-coupled spin systems, therefore, the phase of the MQ-pulse must be included in the portfolio of the sequence parameters to be optimized.
Collapse
Affiliation(s)
- Hyeonjin Kim
- Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.
| | | | | |
Collapse
|
12
|
Napolitano A, Kockenberger W, Auer DP. Reliable gamma aminobutyric acid measurement using optimized PRESS at 3 T. Magn Reson Med 2012; 69:1528-33. [DOI: 10.1002/mrm.24397] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 05/30/2012] [Accepted: 06/07/2012] [Indexed: 12/29/2022]
|
13
|
|
14
|
Geramita M, van der Veen JW, Barnett AS, Savostyanova AA, Shen J, Weinberger DR, Marenco S. Reproducibility of prefrontal γ-aminobutyric acid measurements with J-edited spectroscopy. NMR IN BIOMEDICINE 2011; 24:1089-98. [PMID: 21290458 DOI: 10.1002/nbm.1662] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 11/26/2010] [Accepted: 12/03/2010] [Indexed: 05/13/2023]
Abstract
γ-Aminobutyric acid (GABA) is the chief inhibitory neurotransmitter of the human brain, and GABA-ergic dysfunction has been implicated in a variety of neuropsychiatric disorders. Recent MRS techniques have allowed the quantification of GABA concentrations in vivo, and could therefore provide biologically relevant information. Few reports have formally characterized the reproducibility of these techniques, and differences in field strength, acquisition and processing parameters may result in large differences in measured GABA values. Here, we used a J-edited, single-voxel spectroscopy method of measurement of GABA + macromolecules (GABA + ) in the anterior cingulate cortex (ACC) and right frontal white matter (rFWM) at 3 T. We measured the coefficient of variation within subjects (CVw) and intra-class correlation coefficients on two repeated scans obtained from 10 healthy volunteers with processing procedures developed in-house for the quantification of GABA + and other major metabolites. In addition, by segmenting the spectroscopic voxel into cerebrospinal fluid, gray matter and white matter, and employing a linear regression technique to extrapolate metabolite values to pure gray and white matter, we determined metabolite differences between gray and white matter in ACC and rFWM. CVw values for GABA + /creatine, GABA + /H(2) O, GABA + , creatine, partially co-edited glutamate + glutamine (Glx)/creatine, partially co-edited Glx and N-acetylaspartic acid (NAA)/creatine were all below 12% in both ACC and rFWM. After extrapolation to pure gray and pure white matter, CVw values for all metabolites were below 16%. We found metabolite ratios between gray and white matter for GABA + /creatine, GABA + , creatine, partially co-edited Glx and NAA/creatine to be 0.88 ± 0.21 (standard deviation), 1.52 ± 0.32, 1.77 ± 0.4, 2.69 ± 0.74 and 0.70 ± 0.05, respectively. This study validates a reproducible method for the quantification of brain metabolites, and provides information on gray/white matter differences that may be important in the interpretation of results in clinical populations.
Collapse
Affiliation(s)
- Matthew Geramita
- Unit for Multimodal Imaging Genetics, Clinical Brain Disorders Branch, National Institute of Mental Health, Bethesda, MD 20892, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Herath P, Gallea C, van der Veen JW, Horovitz SG, Hallett M. In vivo neurochemistry of primary focal hand dystonia: a magnetic resonance spectroscopic neurometabolite profiling study at 3T. Mov Disord 2011; 25:2800-8. [PMID: 20979122 DOI: 10.1002/mds.23306] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The neurochemical basis of dystonia is unknown. The purpose of this study was to assess the differences of the inhibitory neurotransmitter, gamma amino butyric acid (GABA), in the sensorimotor cortex and the basal ganglia using magnetic resonance spectroscopy with optimized GABA sensitivity. Twenty-two patients with focal hand dystonia and 22 healthy controls were studied. No significant differences in GABA were observed between the groups in either the sensorimotor cortex or in the basal ganglia.
Collapse
Affiliation(s)
- Priyantha Herath
- Medical Neurology Branch, Human Motor Control Section, NINDS/NIH, Bethesda, Maryland, USA.
| | | | | | | | | |
Collapse
|
16
|
Henry ME, Lauriat TL, Shanahan M, Renshaw PF, Jensen JE. Accuracy and stability of measuring GABA, glutamate, and glutamine by proton magnetic resonance spectroscopy: a phantom study at 4 Tesla. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 208:210-8. [PMID: 21130670 PMCID: PMC4641575 DOI: 10.1016/j.jmr.2010.11.003] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 10/30/2010] [Accepted: 11/08/2010] [Indexed: 05/15/2023]
Abstract
Proton magnetic resonance spectroscopy has the potential to provide valuable information about alterations in gamma-aminobutyric acid (GABA), glutamate (Glu), and glutamine (Gln) in psychiatric and neurological disorders. In order to use this technique effectively, it is important to establish the accuracy and reproducibility of the methodology. In this study, phantoms with known metabolite concentrations were used to compare the accuracy of 2D J-resolved MRS, single-echo 30 ms PRESS, and GABA-edited MEGA-PRESS for measuring all three aforementioned neurochemicals simultaneously. The phantoms included metabolite concentrations above and below the physiological range and scans were performed at baseline, 1 week, and 1 month time-points. For GABA measurement, MEGA-PRESS proved optimal with a measured-to-target correlation of R(2)=0.999, with J-resolved providing R(2)=0.973 for GABA. All three methods proved effective in measuring Glu with R(2)=0.987 (30 ms PRESS), R(2)=0.996 (J-resolved) and R(2)=0.910 (MEGA-PRESS). J-resolved and MEGA-PRESS yielded good results for Gln measures with respective R(2)=0.855 (J-resolved) and R(2)=0.815 (MEGA-PRESS). The 30 ms PRESS method proved ineffective in measuring GABA and Gln. When measurement stability at in vivo concentration was assessed as a function of varying spectral quality, J-resolved proved the most stable and immune to signal-to-noise and linewidth fluctuation compared to MEGA-PRESS and 30 ms PRESS.
Collapse
Affiliation(s)
- Michael E. Henry
- Caritas St. Elizabeth’s Medical Center, Department of Psychiatry, 736 Cambridge St., Boston, MA 02135, USA
- McLean Hospital, Brain Imaging Center, 115 Mill St., Belmont, MA 02478, USA
| | - Tara L. Lauriat
- Caritas St. Elizabeth’s Medical Center, Department of Psychiatry, 736 Cambridge St., Boston, MA 02135, USA
| | - Meghan Shanahan
- McLean Hospital, Brain Imaging Center, 115 Mill St., Belmont, MA 02478, USA
| | - Perry F. Renshaw
- University of Utah School of Medicine, The Brain Institute and Department of Psychiatry, 50 North Medical Dr., Salt Lake City, UT 84132, USA
| | - J. Eric Jensen
- McLean Hospital, Brain Imaging Center, 115 Mill St., Belmont, MA 02478, USA
- Corresponding author. Fax: +1 617 855 2770., (J.E. Jensen)
| |
Collapse
|
17
|
Zhu H, Edden RAE, Ouwerkerk R, Barker PB. High resolution spectroscopic imaging of GABA at 3 Tesla. Magn Reson Med 2010; 65:603-9. [PMID: 21337399 DOI: 10.1002/mrm.22671] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 08/30/2010] [Accepted: 09/14/2010] [Indexed: 12/29/2022]
Abstract
A spin echo-based MRSI sequence was developed to acquire edited spectra of γ-aminobutyric acid in an entire slice. Water and lipid signals were suppressed by a dual-band presaturation sequence, which included integrated outer volume suppression pulses for additional lipid suppression. Experiments in three normal volunteers were performed at 3 T using a 32-channel head coil. High signal-to-noise ratio spectra and metabolic images of γ-aminobutyric acid were acquired from nominal 4.5 cm3 voxels (estimated actual voxel size 7.0 cm3) in a scan time of 17 min. The sequence is also expected to co-edit homocarnosine and macromolecules, giving a composite γ-aminobutyric acid+ resonance. The γ-aminobutyric acid+ to water ratio was measured using a companion water MRSI scan and was found to correlate linearly with the % gray matter (GM) of each voxel (γ-aminobutyric acid+/water=(1.5×GM+3.2)×10(-5), R=0.27), with higher γ-aminobutyric acid+ levels in gray matter compared with white. In conclusion, high signal-to-noise ratio γ-aminobutyric acid-MRSI is possible at 3 T within clinically feasible scan times.
Collapse
Affiliation(s)
- He Zhu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, USA
| | | | | | | |
Collapse
|
18
|
Hasler G, van der Veen JW, Grillon C, Drevets WC, Shen J. Effect of acute psychological stress on prefrontal GABA concentration determined by proton magnetic resonance spectroscopy. Am J Psychiatry 2010; 167:1226-31. [PMID: 20634372 PMCID: PMC3107037 DOI: 10.1176/appi.ajp.2010.09070994] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Impaired function of the central gamma-aminobutyric acid (GABA) system, which provides the brain's major inhibitory pathways, is thought to play an important role in the pathophysiology of anxiety disorders. The effect of acute psychological stress on the human GABA-ergic system is still unknown, however. The purpose of this study was to determine the effect of acute stress on prefrontal GABA levels. METHOD A recently developed noninvasive magnetic resonance spectroscopy method was used to measure changes in the GABA concentration of the prefrontal cortex in 10 healthy human subjects during a threat-of-shock condition and during a safe condition (two sessions on different days). The main outcome measure was the mean GABA concentration within a 3×3×2-cm(3) voxel selected from the medial prefrontal cortex. RESULTS Prefrontal GABA decreased by approximately 18% in the threat-of-shock condition relative to the safe condition. This reduction was specific to GABA, since the concentrations of N-acetyl-aspartate, choline-containing compounds, and glutamate/glutamine levels obtained in the same spectra did not change significantly. CONCLUSIONS This result appeared compatible with evidence from preclinical studies in rodents, which showed rapid presynaptic down-regulation of GABA-ergic neurotransmission in response to acute psychological stress. The molecular mechanism and functional significance of this reduced inhibitory effect of acute psychological stress in relation to impaired GABA-ergic function in anxiety disorders merit further investigation.
Collapse
Affiliation(s)
- Gregor Hasler
- University of Berne, Psychiatric University Hospital, Bolligenstrasse 111, 3000 Berne 60, Switzerland.
| | | | | | | | | |
Collapse
|
19
|
Doelken MT, Hammen T, Bogner W, Mennecke A, Stadlbauer A, Boettcher U, Doerfler A, Stefan H. Alterations of intracerebral γ-aminobutyric acid (GABA) levels by titration with levetiracetam in patients with focal epilepsies. Epilepsia 2010; 51:1477-82. [DOI: 10.1111/j.1528-1167.2010.02544.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Thompson RB, Allen PS. Contamination of single-voxel multiple quantum filters by external water signals arising from intermolecular multiple quantum coherences. Magn Reson Med 2009; 62:796-801. [PMID: 19449371 DOI: 10.1002/mrm.22061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Multiple-quantum filtered pulse sequences simplify overlapping metabolite spectra by the elimination of peaks from uncoupled spin species, most notably from methyl groups and water, and the minimization of unwanted coupled-spin peaks. However, it is shown in this study that a significant contaminant water signal can pass through this family of filters in the form of intermolecular multiple-quantum coherences. An imaging evaluation of a single-voxel multiple quantum filter experiment confirms that the water contamination is excited from outside of the voxel of interest, thus having an increased potential for broad spectral contamination. Phantom and in vivo experiments at 3.0 T are used to illustrate, first, significant water contamination of a single-voxel double quantum filter experiment optimized for the observation of glutamate, and second, the elimination of the unwanted water signal with conventional phase cycling and optimized filter gradient orientations.
Collapse
Affiliation(s)
- Richard B Thompson
- Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
| | | |
Collapse
|
21
|
Snyder J, Hanstock CC, Wilman AH. Spectral editing of weakly coupled spins using variable flip angles in PRESS constant echo time difference spectroscopy: application to GABA. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:245-250. [PMID: 19648038 DOI: 10.1016/j.jmr.2009.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 07/08/2009] [Accepted: 07/08/2009] [Indexed: 05/28/2023]
Abstract
A general in vivo magnetic resonance spectroscopy editing technique is presented to detect weakly coupled spin systems through subtraction, while preserving singlets through addition, and is applied to the specific brain metabolite gamma-aminobutyric acid (GABA) at 4.7 T. The new method uses double spin echo localization (PRESS) and is based on a constant echo time difference spectroscopy approach employing subtraction of two asymmetric echo timings, which is normally only applicable to strongly coupled spin systems. By utilizing flip angle reduction of one of the two refocusing pulses in the PRESS sequence, we demonstrate that this difference method may be extended to weakly coupled systems, thereby providing a very simple yet effective editing process. The difference method is first illustrated analytically using a simple two spin weakly coupled spin system. The technique was then demonstrated for the 3.01 ppm resonance of GABA, which is obscured by the strong singlet peak of creatine in vivo. Full numerical simulations, as well as phantom and in vivo experiments were performed. The difference method used two asymmetric PRESS timings with a constant total echo time of 131 ms and a reduced 120 degrees final pulse, providing 25% GABA yield upon subtraction compared to two short echo standard PRESS experiments. Phantom and in vivo results from human brain demonstrate efficacy of this method in agreement with numerical simulations.
Collapse
Affiliation(s)
- Jeff Snyder
- Department of Physics, University of Alberta, Edmonton, Alberta, Canada.
| | | | | |
Collapse
|
22
|
Research applications of magnetic resonance spectroscopy to investigate psychiatric disorders. Top Magn Reson Imaging 2009; 19:81-96. [PMID: 19363431 DOI: 10.1097/rmr.0b013e318181e0be] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Advances in magnetic resonance spectroscopy (MRS) methodology and related analytic strategies allow sophisticated testing of neurobiological models of disease pathology in psychiatric disorders. An overview of principles underlying MRS, methodological considerations, and investigative approaches is presented. A review of recent research is presented that highlights innovative approaches applying MRS, in particular, hydrogen MRS, to systematically investigate specific psychiatric disorders, including autism spectrum disorders, schizophrenia, panic disorder, major depression, and bipolar disorder.
Collapse
|
23
|
Bogner W, Gruber S, Doelken M, Stadlbauer A, Ganslandt O, Boettcher U, Trattnig S, Doerfler A, Stefan H, Hammen T. In vivo quantification of intracerebral GABA by single-voxel (1)H-MRS-How reproducible are the results? Eur J Radiol 2009; 73:526-31. [PMID: 19201120 DOI: 10.1016/j.ejrad.2009.01.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 12/23/2008] [Accepted: 01/08/2009] [Indexed: 01/24/2023]
Abstract
Gamma aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the human brain. It plays a decisive role in a variety of nervous system disorders, such as anxiety disorders, epilepsy, schizophrenia, insomnia, and many others. The reproducibility of GABA quantification results obtained with a single-voxel spectroscopy J-difference editing sequence with Point Resolved Spectroscopy localization (MEGA-PRESS) was determined on a 3.0 Tesla MR scanner in healthy adults. Eleven volunteers were measured in long- and short-term intervals. Intra- and inter-subject reproducibility were evaluated. Internal referencing of GABA+ to total creatine (tCr) and water (H(2)O), as well as two different post-processing methods for the evaluation (signal integration and time-domain fitting) were compared. In all subjects lower coefficient of variation and therefore higher reproducibility can be observed for fitting compared to integration. The GABA+/tCr ratio performs better than the GABA+/H(2)O ratio or GABA+ without internal referencing for both fitting and integration (GABA+/tCr: 13.3% and 17.0%; GABA+/H(2)O: 15.0% and 17.8%; GABA+: 19.2% and 21.7%). Four-day measurements on three subjects showed higher intra- than inter-subject reproducibility (GABA+/tCr approximately 10-12%). With a coefficient of variation of about 13% for inter-subject and 10-12% for intra-subject variability of GABA+/tCr, this technique seems to be a precise tool that can detect GABA confidently. The results of this study show the reproducibility limitations of GABA quantification in vivo, which are necessary for further clinical studies.
Collapse
Affiliation(s)
- W Bogner
- MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Waehringer Guertel, Vienna, Austria.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Hasler G, van der Veen JW, Geraci M, Shen J, Pine D, Drevets WC. Prefrontal cortical gamma-aminobutyric Acid levels in panic disorder determined by proton magnetic resonance spectroscopy. Biol Psychiatry 2009; 65:273-5. [PMID: 18692172 PMCID: PMC2660669 DOI: 10.1016/j.biopsych.2008.06.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 06/17/2008] [Accepted: 06/24/2008] [Indexed: 01/04/2023]
Abstract
BACKGROUND Panic disorder (PD) is hypothesized to be associated with altered function of the major inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Previous proton magnetic resonance spectroscopy (MRS) studies found lower GABA concentrations in the occipital cortex of subjects with PD relative to healthy control subjects. The current study is the first MRS study to compare GABA concentrations between unmedicated PD subjects and control subjects in the prefrontal cortex (PFC). METHODS Unmedicated subjects with PD (n = 17) and age- and sex-matched healthy control subjects (n = 17) were scanned on a 3 Tesla scanner using a transmit-receive head coil that provided a sufficiently homogenous radiofrequency field to obtain spectroscopic measurements in the dorsomedial/dorsal anterolateral and ventromedial areas of the PFC. RESULTS The prefrontal cortical GABA concentrations did not differ significantly between PD subjects and control subjects. There also was no statistically significant difference in glutamate/glutamine (Glx), choline, or N-acetyl aspartate concentrations. CONCLUSIONS The previously reported finding of reduced GABA concentrations in the occipital cortex of PD subjects does not appear to extend to the PFC.
Collapse
Affiliation(s)
- Gregor Hasler
- Department of Psychiatry, University Hospital, Zurich, Switzerland.
| | | | | | | | | | | |
Collapse
|
25
|
Choi C, Bhardwaj PP, Kalra S, Casault CA, Yasmin US, Allen PS, Coupland NJ. Measurement of GABA and contaminants in gray and white matter in human brain in vivo. Magn Reson Med 2007; 58:27-33. [PMID: 17659613 DOI: 10.1002/mrm.21275] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A preliminary study of discrimination between GABA and macromolecules (MMs) in human brain by proton double quantum filtering (DQF) at 3.0 T in vivo is presented. GABA-tuned and MM-tuned DQ filters were designed with dual-band 180 degrees radiofrequency (RF) pulses that were tuned for selective refocusing of GABA (3.0 and 1.9 ppm) and putative MM resonances (3.0 and 1.7 ppm), respectively. GABA and putative MM signals were extracted from a combined analysis of the filtered mixture signals and the calculated editing yields. Unexpectedly, the GABA and putative MM signals exhibited a similar doublet linewidth at the optimized TE = 82 ms. Furthermore, substantial MM-tuned DQF signal remained at TE = 148 ms, indicating the presence of a component other than MM. With water segmentation data, the GABA-tuned and MM-tuned DQF measures from the medial prefrontal and left frontal lobes were combined to give the concentrations of GABA and the additional component as 1.1 +/- 0.1 and 0.8 +/- 0.1 mM (mean +/- SD, N=3) for gray matter (GM) and 0.4 +/- 0.1 and 0.7+/-0.1 mM (N=3) for white matter (WM), respectively.
Collapse
Affiliation(s)
- Changho Choi
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | | | - Sanjay Kalra
- Neurology Division, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Colin A Casault
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - Umme S Yasmin
- Department of Psychiatry, University of Alberta, Edmonton, Alberta, Canada
| | - Peter S Allen
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | | |
Collapse
|
26
|
Allouche AR, Aubert-Frécon M, Graveron-Demilly D. Quantum chemistry-based NMR spin Hamiltonian parameters of GABA for quantitation in magnetic resonance spectroscopy. Phys Chem Chem Phys 2007; 9:3098-103. [PMID: 17612733 DOI: 10.1039/b700631d] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical shifts delta and spin-spin coupling constants J have been calculated using quantum chemistry approaches for the gamma-amino butyric acid GABA which is a brain metabolite. Two theoretical methods HF and DFT/B3LYP, two basis sets 6-31G* and 6-311+G(2d,p) and two gauge-invariant methods CSGT and GIAO have been used. From delta and J values, NMR spectra have been obtained from the strongly coupled spin system Hamiltonian using the NMR-SCOPE package. Solvent effects have been considered within the polarisable continuum model. Comparisons between calculated and experimental NMR spectra at 300 MHz show that our best results correspond to the B3LYP/6-311+G(2d,p)-GIAO calculations. They are seen to be in good agreement with experiment. This demonstrates the usefulness of quantum chemistry methods for estimating NMR spin Hamiltonian parameters involved in specific algorithms used for quantitation of metabolites such as GABA.
Collapse
Affiliation(s)
- A R Allouche
- Université Lyon1, CNRS, LASIM UMR 5579, bât. A. Kastler, Villeurbanne, France.
| | | | | |
Collapse
|
27
|
Hu J, Yang S, Xuan Y, Jiang Q, Yang Y, Haacke EM. Simultaneous detection of resolved glutamate, glutamine, and gamma-aminobutyric acid at 4 T. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 185:204-13. [PMID: 17223596 PMCID: PMC1995429 DOI: 10.1016/j.jmr.2006.12.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 12/12/2006] [Accepted: 12/13/2006] [Indexed: 05/13/2023]
Abstract
A new approach is introduced to simultaneously detect resolved glutamate (Glu), glutamine (Gln), and gamma-aminobutyric acid (GABA) using a standard STEAM localization pulse sequence with the optimized sequence timing parameters. This approach exploits the dependence of the STEAM spectra of the strongly coupled spin systems of Glu, Gln, and GABA on the echo time TE and the mixing time TM at 4 T to find an optimized sequence parameter set, i.e., {TE, TM}, where the outer-wings of the Glu C4 multiplet resonances around 2.35 ppm, the Gln C4 multiplet resonances around 2.45 ppm, and the GABA C2 multiplet resonance around 2.28 ppm are significantly suppressed and the three resonances become virtual singlets simultaneously and thus resolved. Spectral simulation and optimization were conducted to find the optimized sequence parameters, and phantom and in vivo experiments (on normal human brains, one patient with traumatic brain injury, and one patient with brain tumor) were carried out for verification. The results have demonstrated that the Gln, Glu, and GABA signals at 2.2-2.5 ppm can be well resolved using a standard STEAM sequence with the optimized sequence timing parameters around {82 ms,48 ms} at 4 T, while the other main metabolites, such as N-acetyl aspartate (NAA), choline (tCho), and creatine (tCr), are still preserved in the same spectrum. The technique can be easily implemented and should prove to be a useful tool for the basic and clinical studies associated with metabolism of Glu, Gln, and/or GABA.
Collapse
Affiliation(s)
- Jiani Hu
- Department of Radiology, Wayne State University, and Department of Neurology, Henry Ford Hospital, Detroit, MI 48201, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Waddell KW, Avison MJ, Joers JM, Gore JC. A practical guide to robust detection of GABA in human brain by J-difference spectroscopy at 3 T using a standard volume coil. Magn Reson Imaging 2007; 25:1032-8. [PMID: 17707165 PMCID: PMC2131736 DOI: 10.1016/j.mri.2006.11.026] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 11/29/2006] [Accepted: 11/30/2006] [Indexed: 11/24/2022]
Abstract
gamma-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in human brain and has been implicated in several neuropsychiatric disorders. In vivo human brain GABA concentrations are near the detection limit for magnetic resonance spectroscopy ( approximately 1 mM), and because of overlap with more abundant compounds, spectral editing is generally necessary to detect GABA. In previous reports, GABA spectra edited by J-difference spectroscopy vary considerably in appearance. We have evaluated the factors that affect GABA spectra and the conditions necessary for robust acquisition of J-difference spectra from arbitrary brain regions. In particular, we demonstrate that variations in spectral quality can be explained in part by the incoherent addition of transients that results from shot to shot frequency and phase variations. An automated time-domain spectral alignment strategy that enables reproducible acquisition of high-quality GABA spectra at 3 T with a standard 30-cm T/R volume coil is presented. Representative GABA spectra from human frontal lobe, an area where susceptibility-induced frequency and phase variations are especially troublesome, that demonstrate the robustness of the acquisition and data handling strategy used in this study are presented.
Collapse
Affiliation(s)
- Kevin W Waddell
- Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232-2675, USA.
| | | | | | | |
Collapse
|
29
|
Choi IY, Lee SP, Merkle H, Shen J. In vivo detection of gray and white matter differences in GABA concentration in the human brain. Neuroimage 2006; 33:85-93. [PMID: 16884929 DOI: 10.1016/j.neuroimage.2006.06.016] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 05/26/2006] [Accepted: 06/18/2006] [Indexed: 12/11/2022] Open
Abstract
A novel selective multiple quantum filtering-based chemical shift imaging method was developed for acquiring GABA images in the human brain at 3 T. This method allows a concomitant acquisition of an interleaved total creatine image with the same spatial resolution. Using T(1)-based image segmentation and a nonlinear least square regression analysis of GABA-to-total creatine concentration ratios in frontal and parietal lobes of healthy adult volunteers as a function of the tissue gray matter fraction, the mean GABA concentration in gray and white matter was determined to be 1.30+/-0.36 micromol/g and 0.16+/-0.16 micromol/g (mean+/-SD, n=13), respectively. It is expected that this method will become a useful tool for studying GABAergic function in the human brain in vivo.
Collapse
Affiliation(s)
- In-Young Choi
- The Nathan Kline Institute, Medical Physics, Orangeburg, NY 10962, USA.
| | | | | | | |
Collapse
|
30
|
Selvaraj S, Wylezinska M, Evans J, Jezzard P, Matthews PM, Cowen PJ. Tryptophan depletion does not lower brain GABA levels in healthy volunteers. Psychopharmacology (Berl) 2006; 187:131-2. [PMID: 16767423 DOI: 10.1007/s00213-006-0407-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 04/04/2006] [Indexed: 10/24/2022]
|
31
|
Wang PW, Sailasuta N, Chandler RA, Ketter TA. Magnetic resonance spectroscopic measurement of cerebral gamma-aminobutyric acid concentrations in patients with bipolar disorders. Acta Neuropsychiatr 2006; 18:120-6. [PMID: 26989801 DOI: 10.1111/j.1601-5215.2006.00132.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Animal models of depression and psychopharmacological mechanisms of action suggest the importance of the gamma-amino butyric acid (GABA) system in the pathophysiology of mood disorders. Mood stabilizers have overlapping effects on GABAergic neurotransmission, and antidepressant use has been associated with alterations in GABAB receptor function. Magnetic resonance spectroscopy (MRS) provides an opportunity to noninvasively assess cerebral GABA concentrations in anterior paralimbic circuits that have been implicated in mood disorders. METHODS In bipolar disorder patients and healthy control subjects, we used MRS with a modified GABA-edited point resolved spectroscopy sequence (TE 68 ms, TR 1500 ms, 512 averages, total scan time 26 min) to assess GABA in an 18-cm3 occipital voxel. In addition, in another cohort of bipolar disorder patients and healthy control subjects, we similarly assessed GABA in a 12.5-cm3 medial prefrontal/anterior cingulate (MPF/AC) voxel. The concentration of GABA was referenced to creatine (Cr) from unedited spectra. RESULTS In bipolar patients and controls, we consistently detected 3.0 p.p.m. GABA peaks in occipital lobe and MPF/AC. In 16 bipolar (nine bipolar I and seven bipolar II) disorder patients, compared with six healthy control subjects, mean occipital GABA/Cr concentration was 61% higher. In addition, in 15 bipolar (five bipolar I, nine bipolar II, and one bipolar not otherwise specified) disorder patients, compared with six healthy control subjects, mean MPF/AC GABA/Cr concentration tended to be 41% higher. CONCLUSIONS Patients with bipolar disorders may have increased cerebral GABA concentrations. Although this was more evident in the occipital lobe, MPC/AC GABA disturbance may be of greater potential interest in view the more established role of MPF/AC in affective processing. Additional studies are warranted to assess changes in GABAergic neurotransmission and the influences of diagnosis, mood state, and medication status in bipolar disorder patients.
Collapse
Affiliation(s)
- Po W Wang
- 1Department of Psychiatry and Behavioral Sciences, Bipolar Disorders Clinic, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | - Terence A Ketter
- 1Department of Psychiatry and Behavioral Sciences, Bipolar Disorders Clinic, Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|
32
|
Hasler G, Neumeister A, van der Veen JW, Tumonis T, Bain EE, Shen J, Drevets WC, Charney DS. Normal prefrontal gamma-aminobutyric acid levels in remitted depressed subjects determined by proton magnetic resonance spectroscopy. Biol Psychiatry 2005; 58:969-73. [PMID: 16043137 DOI: 10.1016/j.biopsych.2005.05.017] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2005] [Revised: 04/21/2005] [Accepted: 05/10/2005] [Indexed: 11/29/2022]
Abstract
BACKGROUND There is growing evidence that the brain gamma-aminobutyric acid (GABA) system is involved in depression. Lowered plasma GABA levels were identified as a traitlike abnormality found in patients with remitted unipolar depression and in healthy first-degree relatives of patients with unipolar depression. Major depressive disorder has been associated with neuroimaging and neuropathological abnormalities in the prefrontal cortex by various types of evidence. As a result, the current study investigates whether GABA levels in the prefrontal cortex differ between unmedicated subjects with remitted major depressive disorder (rMDD) and healthy control subjects. METHODS Sixteen rMDD subjects and 15 healthy control subjects underwent magnetic resonance spectroscopy. We used a 3 Tesla GE whole body scanner with a homogeneous resonator coil providing a homogenous radiofrequency field and capability of obtaining measurement from the prefrontal cortex. Gamma-aminobutyric acid levels were measured in the ventromedial prefrontal cortex and dorsolateral/anterior medial prefrontal cortex. RESULTS There was no difference in GABA concentrations between rMDD subjects and healthy control subjects in the ventromedial prefrontal cortex and dorsolateral/anterior medial prefrontal cortex. Secondary analyses provided preliminary evidence for a negative relationship between the glutamate/glutamine (Glx)/GABA ratio and age of onset of major depression in the ventromedial prefrontal cortex. CONCLUSIONS This result suggests that GABA levels in the prefrontal cortex, if found to be reduced in symptomatic depression, do not represent a persistent characteristic of major depression. Further research is needed to determine brain GABA levels in different brain regions, in different stages of depressive illness, and in different depressive subtypes.
Collapse
Affiliation(s)
- Gregor Hasler
- Mood and Anxiety Disorders Program, Section on Experimental Therapeutics, National Institutes of Health, Bethesda, MD 20892-2670, USA.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Jensen JE, Frederick BDB, Renshaw PF. Grey and white matter GABA level differences in the human brain using two-dimensional, J-resolved spectroscopic imaging. NMR IN BIOMEDICINE 2005; 18:570-6. [PMID: 16273508 DOI: 10.1002/nbm.994] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A novel, two-dimensional, J-resolved chemical-shift imaging sequence was used to collect gamma-aminobutyric acid (GABA) spectroscopic imaging data on six healthy subjects at 4 T. Using image segmentation and a linear-regression analysis relating brain GABA level to tissue-type, a consistent and significant (n = 6, p < 0.01) elevation of mean GABA levels was measured in the cortical grey matter (0.96 +/- 0.24 mm) compared with white matter (0.44 +/- 0.16 mm) across all six subjects. The results suggest an approximately two-fold elevation of GABA levels in cortical grey matter compared with white matter in vivo. Our findings are consistent with ex vivo studies in the literature of both animal and human brain and demonstrate the significant potential of this technique for detecting and quantifying tissue-specific neurochemical pathology in vivo.
Collapse
Affiliation(s)
- J Eric Jensen
- Brain Imaging Center, McLean Hospital, Belmont, MA 02478-9106, USA
| | | | | |
Collapse
|
34
|
Abstract
Magnetic resonance spectroscopy (MRS) has been used for more than two decades to interrogate metabolite distributions in living cells and tissues. Techniques have been developed that allow multiple spectra to be obtained simultaneously with individual volume elements as small as 1 uL of tissue (i.e., 1 x 1 x 1 mm(3)). The most common modern applications of in vivo MRS use endogenous signals from (1)H, (31)P, or (23)Na. Important contributions have also been made using exogenous compounds containing (19)F, (13)C, or (17)O. MRS has been used to investigate cardiac and skeletal muscle energetics, neurobiology, and cancer. This review focuses on the latter applications, with specific reference to the measurement of tissue choline, which has proven to be a tumor biomarker that is significantly affected by anticancer therapies.
Collapse
Affiliation(s)
- Robert J Gillies
- Arizona Cancer Center, 1515 Campbell Avenue, Tucson, AZ 85724-5024, USA.
| | | |
Collapse
|
35
|
Choi IY, Lee SP, Shen J. Selective homonuclear Hartmann-Hahn transfer method for in vivo spectral editing in the human brain. Magn Reson Med 2005; 53:503-10. [PMID: 15723418 DOI: 10.1002/mrm.20381] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A novel selective homonuclear Hartmann-Hahn transfer method for in vivo spectral editing is proposed and applied to measurements of gamma-aminobutyric acid (GABA) in the human brain at 3 T. The proposed method utilizes a new concept for in vivo spectral editing, the spectral selectivity of which is not based on a conventional editing pulse but based on the stringent requirement of the doubly selective Hartmann-Hahn match. The sensitivity and spectral selectivity of GABA detection achieved by this doubly selective Hartmann-Hahn match scheme was superior to that achievable by conventional in vivo spectral editing techniques providing both sensitivity enhancement and excellent suppression of overlapping resonances in a single shot. Since double-quantum filtering gradients were not employed, singlets such as the NAA methyl group at 2.02 ppm and the creatine methylene group at 3.92 ppm were detected simultaneously. These singlets may serve as navigators for the spectral phase of GABA and for frequency shifts during measurements. The estimated concentration of GABA in the frontoparietal region of the human brain in vivo was 0.7 +/- 0.2 mumol/g (mean +/- SD, n = 12).
Collapse
Affiliation(s)
- In-Young Choi
- Medical Physics, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA.
| | | | | |
Collapse
|
36
|
Abstract
Neuroimaging has important applications in the diagnosis and treatment of patients with seizures and epilepsy. Having replaced computed tomography (CT) in many situations, MRI is the preferred imaging technique for patients with epilepsy. Advances in radionuclide-based techniques such as single-photon emission CT/positron emission tomography and electromagnetic source imaging with magnetoencephalography are providing new insights into the pathophysiology of epilepsy. In addition, techniques such as magnetic resonance spectroscopy are beginning to impact treatment. In this review, I discuss how these techniques are used in clinical practice but more importantly, how imaging findings play an increasing role in neurotherapeutics.
Collapse
Affiliation(s)
- Ruben I Kuzniecky
- New York University Epilepsy Center, Department of Neurology, New York University School of Medicine, New York, New York 10016, USA
| |
Collapse
|
37
|
Abstract
1H and 31P spectroscopy detects relevant metabolite changes in patients with TLE. Numerous studies confirm reduction in NAA and in the ratio of PCr/Pi. In his 1999 review, Kuzniecky concluded that proton MRS, using single-voxel or chemical shift imaging, lateralizes temporal lobe epilepsy in 65% to 96% of cases, with bilateral changes seen in 35% to 45% of cases, whereas phosphorus MRS shows a lateralizing PCr/Pi ratio in 65% to 75% of the TLE patients. There are indications that these changes are reversible with seizure treatment. Improvements in MRS technology, such as the ability to calculate absolute concentrations, to account for differences be-tween gray and white matter and to achieve better spectral resolution by use of a higher magnetic field strength, will now allow more extensive use of this technique for patients with epilepsy.
Collapse
Affiliation(s)
- Ruben Kuzniecky
- NYU Comprehensive Epilepsy Center, New York University School of Medicine, 403 East 34th Street, New York, NY 10016, USA.
| |
Collapse
|
38
|
Chen Z, Silva AC, Yang J, Shen J. Elevated endogenous GABA level correlates with decreased fMRI signals in the rat brain during acute inhibition of GABA transaminase. J Neurosci Res 2005; 79:383-91. [PMID: 15619231 DOI: 10.1002/jnr.20364] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Vigabatrin and gabaculine, both highly specific inhibitors of GABA (gamma-aminobutyric acid) transaminase, cause significant elevation of endogenous GABA levels in brain. The time course of GABA concentration after acute GABA transaminase inhibition was measured quantitatively in the alpha-chloralose-anesthetized rat brain using in vivo selective homonuclear polarization transfer spectroscopy. The blood oxygenation level-dependent (BOLD) effect in functional magnetic resonance imaging (fMRI) has been considered to be coupled tightly to neuronal activation via the metabolic demand of associated glutamate transport. Correlated with the rise in endogenous GABA level after vigabatrin or gabaculine treatment, the intensity of BOLD-weighted fMRI signals in rat somatosensory cortex during forepaw stimulation was found to be reduced significantly. These results are consistent with previous findings that inhibition of GABA transaminase leads to augmented GABA release and potentiation of GABAergic inhibition.
Collapse
Affiliation(s)
- Zhengguang Chen
- Molecular Imaging Branch, NIMH, Bethesda, MD 20892-1527, USA
| | | | | | | |
Collapse
|
39
|
Choi C, Coupland NJ, Hanstock CC, Ogilvie CJ, Higgins ACM, Gheorghiu D, Allen PS. Brain γ-aminobutyric acid measurement by proton double-quantum filtering with selectiveJ rewinding. Magn Reson Med 2005; 54:272-9. [PMID: 16032672 DOI: 10.1002/mrm.20563] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An optimized single-shot proton double-quantum (DQ) filter for the quantification of gamma-aminobutyric acid (GABA) levels in human brain is reported. It is demonstrated that creation of DQ coherences following dual-resonance-selective refocusing gives a theoretical editing efficiency of 50% for the detection of the GABA resonance at 3.01 ppm. The sequence times are optimized with both numerical and experimental analyses of the editing performance, giving an experimental editing efficiency of 42%. It is acknowledged that homocarnosine is partially coedited, leading to a 20% contribution to the edited signal; however, macromolecule contamination is negligible in vivo under these experimental conditions. The GABA concentration in human prefrontal cortex is estimated to be 0.8 +/- 0.1 micromol/g (mean +/- SD, n = 6), with reference to the internal standard creatine at 9 micromol/g.
Collapse
Affiliation(s)
- Changho Choi
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | | | | | |
Collapse
|
40
|
Jensen JE, Frederick BD, Wang L, Brown J, Renshaw PF. Two-dimensional, J-resolved spectroscopic imaging of GABA at 4 Tesla in the human brain. Magn Reson Med 2005; 54:783-8. [DOI: 10.1002/mrm.20644] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
41
|
Choi IY, Lee SP, Shen J. In vivo single-shot three-dimensionally localized multiple quantum spectroscopy of GABA in the human brain with improved spectral selectivity. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2005; 172:9-16. [PMID: 15589402 DOI: 10.1016/j.jmr.2004.09.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 09/07/2004] [Indexed: 05/24/2023]
Abstract
A single-shot multiple quantum filtering method is developed that uses two double-band frequency selective pulses for enhanced spectral selectivity in combination with a slice-selective 90 degrees, a slice-selective universal rotator 90 degrees, and a spectral-spatial pulse composed of two slice-selective universal rotator 45 degrees pulses for single-shot three-dimensional localization. The use of this selective multiple quantum filtering method for C(3) and C(4) methylene protons of GABA resulted in improved spectral selectivity for GABA and effective suppression of overlapping signals such as creatine and glutathione in each single scan, providing reliable measurements of the GABA doublet in all subjects. The concentration of GABA was measured to be 0.7 +/- 0.2 micromol/g (means +/- SD, n = 15) in the fronto-parietal region of the human brain in vivo.
Collapse
Affiliation(s)
- In-Young Choi
- The Nathan Kline Institute, Medical Physics, Orangeburg, NY 10962, USA.
| | | | | |
Collapse
|
42
|
Shen J, Yang J, Choi IY, Li SS, Chen Z. A new strategy for in vivo spectral editing. Application to GABA editing using selective homonuclear polarization transfer spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 170:290-298. [PMID: 15388093 DOI: 10.1016/j.jmr.2004.05.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Revised: 05/05/2004] [Indexed: 05/24/2023]
Abstract
A novel single-shot in vivo spectral editing method is proposed in which the signal to be detected, is regenerated anew from the thermal equilibrium magnetization of a source to which it is J-coupled. The thermal equilibrium magnetization of the signal to be detected together with those of overlapping signals are suppressed by single-shot gradient dephasing prior to the signal regeneration process. Application of this new strategy to in vivo GABA editing using selective homonuclear polarization transfer allows complete suppression of overlapping creatine and glutathione while detecting the GABA-4 methylene resonance at 3.02 ppm with an editing yield similar to that of conventional editing methods. The NAA methyl group at 2.02 ppm was simultaneously detected and can be used as an internal navigator echo for correcting the zero order phase and frequency shifts and as an internal reference for concentration. This new method has been demonstrated for robust in vivo GABA editing in the rat brain and for study of GABA synthesis after acute vigabatrin administration.
Collapse
Affiliation(s)
- Jun Shen
- Molecular Imaging Branch, National Institute of Mental Health, Building 10, Room 2D51A, 9000 Rockville Pike, Bethesda, MD 20892-1527, USA.
| | | | | | | | | |
Collapse
|
43
|
Choi IY, Lee SP, Merkle H, Shen J. Single-shot two-echo technique for simultaneous measurement of GABA and creatine in the human brain in vivo. Magn Reson Med 2004; 51:1115-21. [PMID: 15170830 DOI: 10.1002/mrm.20082] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A single-shot, two-echo method for the simultaneous detection of multiple-quantum (MQ)-filtered gamma-aminobutyric acid (GABA) and creatine (Cr) was developed and demonstrated in the human brain in vivo at 3 Tesla. The simultaneously measured Cr singlet served as a navigator for the spectral phase of GABA and any frequency shift during measurements due to drift in the static magnetic field (B(0)) or subject movement, as well as an internal concentration reference. In addition, the use of a double-band frequency-selective MQ filter for C(3) and C(4) methylene protons of GABA provided a very robust measurement of GABA, with excellent suppression of overlapping metabolites such as Cr and glutathione (GSH) in each single scan. Contamination from overlapping macromolecules was also demonstrated to be negligible with this method. The GABA-to-Cr ratio was 0.09 +/- 0.03 (mean +/- SD, N = 17) and the estimated concentration of GABA in the frontoparietal region of the human brain in vivo was 0.66 +/- 0.19 micromol/g (mean +/- SD, N = 17) with the internal reference method, and 0.69 +/- 0.18 micromol/g (mean +/- SD, N = 17) with the external reference method. The observed pattern of GABA doublet was consistent among all subjects, with a frequency separation of approximately 13 Hz.
Collapse
Affiliation(s)
- In-Young Choi
- Nathan Kline Institute, Medical Physics, Orangeburg, New York 10962, USA.
| | | | | | | |
Collapse
|
44
|
Du F, Chu WJ, Yang B, Den Hollander JA, Ng TC. In vivo GABA detection with improved selectivity and sensitivity by localized double quantum filter technique at 4.1T. Magn Reson Imaging 2004; 22:103-8. [PMID: 14972399 DOI: 10.1016/j.mri.2003.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2002] [Revised: 06/02/2003] [Accepted: 06/03/2003] [Indexed: 11/24/2022]
Abstract
Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter for the normal function of mammal and human brain. It is difficult to detect GABA signal with the conventional single quantum technique due to its relatively low concentration and overlapping with other signals from creatine (Cr), glutathione (GSH), as well as macromolecules. Using a high-selective read pulse, DANTE, and at the facility of increased sensitivity and chemical shift resolution at high-field 4.1T, GABA editing by double quantum filter (DQF) with robust suppression of Cr and GSH was achieved. Our editing efficiency of 40-50% was achievable on a GABA phantom (50 mM GABA and 61 mM choline). Furthermore, GABA editing spectra were acquired with echo time TE = 77 ms, and any possible macromolecular contamination to GABA editing spectra was found to be negligible. This high-field DQF setup was applied to 11 healthy volunteers, and the mean GABA level was measured to be 1.12 +/- 0.15 mM in the occipital lobe in reference to 7.1 mM Cr concentration.
Collapse
Affiliation(s)
- Fei Du
- Department of Medicine and Comprehensive Cancer Center, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35205, USA
| | | | | | | | | |
Collapse
|
45
|
Trabesinger AH, Meier D, Boesiger P. In vivo 1H NMR spectroscopy of individual human brain metabolites at moderate field strengths. Magn Reson Imaging 2003; 21:1295-302. [PMID: 14725936 DOI: 10.1016/j.mri.2003.08.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
This article reviews spectral editing techniques for in vivo 1H NMR spectroscopy of human brain tissue at moderate field strengths of 1.5-3 Tesla. Various aspects of 1H NMR spectroscopy are discussed with regard to in vivo applications. The parameter set [delta, J, n] (delta being the relative chemical shift, J the scalar coupling constant and n the number of coupled spins) is used to characterize the spin systems under investigation and to classify the editing techniques that are used in in vivo 1H NMR spectroscopy.
Collapse
Affiliation(s)
- Andreas H Trabesinger
- Institute for Biomedical Engineering, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | | | | |
Collapse
|
46
|
Shen J. Slice-selective J-coupled coherence transfer using symmetric linear phase pulses: applications to localized GABA spectroscopy. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2003; 163:73-80. [PMID: 12852909 DOI: 10.1016/s1090-7807(03)00112-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Symmetric, linear phase, slice-selective RF pulses were analyzed theoretically for performing slice-selective coherence transfer. It was shown using numerical simulations of product operators that, when a prefocusing gradient of the same area as that of the refocusing gradient is added, these pulses become slice-selective universal rotator pulses, therefore, capable of performing slice-selective coherence transfer. As an example, a slice-selective universal rotator pulse based on a seven-lobe hamming-filtered sinc pulse was applied to in vivo single-shot simultaneous spectral editing and spatial localization of neurotransmitter GABA in the human brain.
Collapse
Affiliation(s)
- Jun Shen
- Molecular Imaging Branch, Mood and Anxiety Disorders Program, National Institute of Mental Health, 9000 Rockville Pike, MSC 1527, Bethesda, MD 20892-1527, USA.
| |
Collapse
|
47
|
Simister RJ, McLean MA, Barker GJ, Duncan JS. A proton magnetic resonance spectroscopy study of metabolites in the occipital lobes in epilepsy. Epilepsia 2003; 44:550-8. [PMID: 12681004 DOI: 10.1046/j.1528-1157.2003.19102.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE gamma-Amino butyric acid (GABA) and glutamate, respectively the principal inhibitory and excitatory neurochemicals in the brain, are visible to proton magnetic resonance spectroscopy (MRS). We report a study of GABA+ (GABA plus homocarnosine) and GLX (glutamate plus glutamine) concentrations in the occipital lobes in patients with idiopathic generalised epilepsy (IGE) and in patients with occipital lobe epilepsy (OLE). METHODS Fifteen patients with IGE, 15 patients with OLE, and 15 healthy volunteers were studied. A single voxel was prescribed in the occipital lobes for each subject. PRESS localised short-echo-time MRS was performed to measure GLX by using LCModel. A double quantum GABA filter was used to measure GABA+. Segmented T1-weighted images gave the tissue composition of the prescribed voxel. RESULTS Grey-matter proportion, GLX, and GABA+ were all elevated in IGE. However, analysis using grey-matter proportion as a covariable showed no significant group differences. No correlation was observed between GABA+ concentration and either seizure frequency or time since last seizure. CONCLUSIONS GLX and GABA+ were elevated in IGE. Elevated grey-matter content in the IGE group despite normal MRI appearance can be expected to account for some or all of this observed elevation of GLX and GABA+. GABA+ concentration did not correlate with seizure control or duration since most recent seizure.
Collapse
|
48
|
Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2002; 15:367-374. [PMID: 12224543 DOI: 10.1002/nbm.750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|