151
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Zarinabad N, Abernethy LJ, Avula S, Davies NP, Rodriguez Gutierrez D, Jaspan T, MacPherson L, Mitra D, Rose HEL, Wilson M, Morgan PS, Bailey S, Pizer B, Arvanitis TN, Grundy RG, Auer DP, Peet A. Application of pattern recognition techniques for classification of pediatric brain tumors by in vivo 3T 1 H-MR spectroscopy-A multi-center study. Magn Reson Med 2017; 79:2359-2366. [PMID: 28786132 PMCID: PMC5850456 DOI: 10.1002/mrm.26837] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 11/30/2022]
Abstract
Purpose 3T magnetic resonance scanners have boosted clinical application of 1H‐MR spectroscopy (MRS) by offering an improved signal‐to‐noise ratio and increased spectral resolution, thereby identifying more metabolites and extending the range of metabolic information. Spectroscopic data from clinical 1.5T MR scanners has been shown to discriminate between pediatric brain tumors by applying machine learning techniques to further aid diagnosis. The purpose of this multi‐center study was to investigate the discriminative potential of metabolite profiles obtained from 3T scanners in classifying pediatric brain tumors. Methods A total of 41 pediatric patients with brain tumors (17 medulloblastomas, 20 pilocytic astrocytomas, and 4 ependymomas) were scanned across four different hospitals. Raw spectroscopy data were processed using TARQUIN. Borderline synthetic minority oversampling technique was used to correct for the data skewness. Different classifiers were trained using linear discriminative analysis, support vector machine, and random forest techniques. Results Support vector machine had the highest balanced accuracy for discriminating the three tumor types. The balanced accuracy achieved was higher than the balanced accuracy previously reported for similar multi‐center dataset from 1.5T magnets with echo time 20 to 32 ms alone. Conclusion This study showed that 3T MRS can detect key differences in metabolite profiles for the main types of childhood tumors. Magn Reson Med 79:2359–2366, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Niloufar Zarinabad
- Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Laurence J Abernethy
- Department of Radiology, Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom
| | - Shivaram Avula
- Department of Radiology, Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom
| | - Nigel P Davies
- Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital, Birmingham, United Kingdom.,Department of Imaging and Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Daniel Rodriguez Gutierrez
- The Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom.,Medical Physics, Nottingham University Hospital, Queen's Medical Centre, Nottingham, United Kingdom
| | - Tim Jaspan
- The Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom.,Neuroradiology, Nottingham University Hospital, Queen's Medical Centre, Nottingham, United Kingdom
| | | | - Dipayan Mitra
- Neuroradiology Department, Newcastle upon Tyne Hospitals, Newcastle upon Tyne, United Kingdom
| | - Heather E L Rose
- Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Martin Wilson
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom
| | - Paul S Morgan
- The Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom.,Medical Physics, Nottingham University Hospital, Queen's Medical Centre, Nottingham, United Kingdom.,Radiological Sciences, Department of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom
| | - Simon Bailey
- Paediatric Oncology Department, Great North Children's Hospital, Newcastle upon Tyne, United Kingdom
| | - Barry Pizer
- Department of Paediatric Oncology, Alder Hey Children's NHS Foundation Trust, Liverpool, United Kingdom
| | - Theodoros N Arvanitis
- Birmingham Children's Hospital, Birmingham, United Kingdom.,Institute of Digital Healthcare, WMG, University of Warwick, Coventry, United Kingdom
| | - Richard G Grundy
- The Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom
| | - Dorothee P Auer
- The Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom.,Neuroradiology, Nottingham University Hospital, Queen's Medical Centre, Nottingham, United Kingdom.,Radiological Sciences, Department of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom
| | - Andrew Peet
- Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital, Birmingham, United Kingdom
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152
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Ford TC, Nibbs R, Crewther DP. Glutamate/GABA+ ratio is associated with the psychosocial domain of autistic and schizotypal traits. PLoS One 2017; 12:e0181961. [PMID: 28759626 PMCID: PMC5536272 DOI: 10.1371/journal.pone.0181961] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 07/10/2017] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The autism and schizophrenia spectra overlap to a large degree in the social and interpersonal domains. Similarly, abnormal excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) neurotransmitter concentrations have been reported for both spectra, with the interplay of these neurotransmitters important for cortical excitation to inhibition regulation. This study investigates whether these neurotransmitter abnormalities are specific to the shared symptomatology, and whether the degree of abnormality increases with increasing symptom severity. Hence, the relationship between the glutamate/GABA ratio and autism and schizophrenia spectrum traits in an unmedicated, subclinical population was investigated. METHODS A total of 37 adults (19 female, 18 male) aged 18-38 years completed the Autism Spectrum Quotient (AQ) and Schizotypal Personality Questionnaire (SPQ), and participated in the resting state proton magnetic resonance spectroscopy study in which sequences specific for quantification of glutamate and GABA+ concentration were applied to a right and left superior temporal voxel. RESULTS There were significant, moderate, positive relationships between right superior temporal glutamate/GABA+ ratio and AQ, SPQ and AQ+SPQ total scores (p<0.05), SPQ subscales Social Anxiety, No Close Friend, Constricted Affect, Odd Behaviour, Odd Speech, Ideas of Reference and Suspiciousness, and AQ subscales Social Skills, Communication and Attention Switching (p<0.05); increased glutamate/GABA+ coinciding with higher scores on these subscales. Only the relationships between glutamate/GABA+ ratio and Social Anxiety, Constricted Affect, Social Skills and Communication survived multiple comparison correction (p< 0.004). Left superior temporal glutamate/GABA+ ratio reduced with increasing restricted imagination (p<0.05). CONCLUSION These findings demonstrate evidence for an association between excitatory/inhibitory neurotransmitter concentrations and symptoms that are shared between the autism and schizophrenia spectra.
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Affiliation(s)
- Talitha C. Ford
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Richard Nibbs
- Swinburne Neuroimaging, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - David P. Crewther
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
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153
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Ford TC, Nibbs R, Crewther DP. Increased glutamate/GABA+ ratio in a shared autistic and schizotypal trait phenotype termed Social Disorganisation. Neuroimage Clin 2017; 16:125-131. [PMID: 28794973 PMCID: PMC5537407 DOI: 10.1016/j.nicl.2017.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/19/2017] [Accepted: 07/12/2017] [Indexed: 01/01/2023]
Abstract
Autism and schizophrenia are multi-dimensional spectrum disorders that have substantial phenotypic overlap. This overlap is readily identified in the non-clinical population, and has been conceptualised as Social Disorganisation (SD). This study investigates the balance of excitatory glutamate and inhibitory γ-aminobutyric acid (GABA) concentrations in a non-clinical sample with high and low trait SD, as glutamate and GABA abnormalities are reported across the autism and schizophrenia spectrum disorders. Participants were 18 low (10 females) and 19 high (9 females) SD scorers aged 18 to 40 years who underwent 1H-MRS for glutamate and GABA+macromolecule (GABA+) concentrations in right and left hemisphere superior temporal (ST) voxels. Reduced GABA+ concentration (p = 0.03) and increased glutamate/GABA+ ratio (p = 0.003) in the right ST voxel for the high SD group was found, and there was increased GABA+ concentration in the left compared to right ST voxel (p = 0.047). Bilateral glutamate concentration was increased for the high SD group (p = 0.006); there was no hemisphere by group interaction (p = 0.772). Results suggest that a higher expression of the SD phenotype may be associated with increased glutamate/GABA+ ratio in the right ST region, which may affect speech prosody processing, and lead behavioural characteristics that are shared within the autistic and schizotypal spectra.
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Affiliation(s)
- Talitha C. Ford
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - Richard Nibbs
- Swinburne Neuroimaging, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
| | - David P. Crewther
- Centre for Human Psychopharmacology, Faculty of Heath, Arts and Design, Swinburne University of Technology, Melbourne, Victoria, Australia
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154
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Iqbal Z, Wilson NE, Thomas MA. Prior-knowledge Fitting of Accelerated Five-dimensional Echo Planar J-resolved Spectroscopic Imaging: Effect of Nonlinear Reconstruction on Quantitation. Sci Rep 2017; 7:6262. [PMID: 28740202 PMCID: PMC5524913 DOI: 10.1038/s41598-017-04065-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/08/2017] [Indexed: 11/14/2022] Open
Abstract
1H Magnetic Resonance Spectroscopic imaging (SI) is a powerful tool capable of investigating metabolism in vivo from mul- tiple regions. However, SI techniques are time consuming, and are therefore difficult to implement clinically. By applying non-uniform sampling (NUS) and compressed sensing (CS) reconstruction, it is possible to accelerate these scans while re- taining key spectral information. One recently developed method that utilizes this type of acceleration is the five-dimensional echo planar J-resolved spectroscopic imaging (5D EP-JRESI) sequence, which is capable of obtaining two-dimensional (2D) spectra from three spatial dimensions. The prior-knowledge fitting (ProFit) algorithm is typically used to quantify 2D spectra in vivo, however the effects of NUS and CS reconstruction on the quantitation results are unknown. This study utilized a simulated brain phantom to investigate the errors introduced through the acceleration methods. Errors (normalized root mean square error >15%) were found between metabolite concentrations after twelve-fold acceleration for several low concentra- tion (<2 mM) metabolites. The Cramér Rao lower bound% (CRLB%) values, which are typically used for quality control, were not reflective of the increased quantitation error arising from acceleration. Finally, occipital white (OWM) and gray (OGM) human brain matter were quantified in vivo using the 5D EP-JRESI sequence with eight-fold acceleration.
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Affiliation(s)
- Zohaib Iqbal
- University of California - Los Angeles, Radiological Sciences, Los Angeles, California, 90095, USA
| | - Neil E Wilson
- University of California - Los Angeles, Radiological Sciences, Los Angeles, California, 90095, USA
| | - M Albert Thomas
- University of California - Los Angeles, Radiological Sciences, Los Angeles, California, 90095, USA.
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155
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Bogner W, Hangel G, Esmaeili M, Andronesi OC. 1D-spectral editing and 2D multispectral in vivo 1H-MRS and 1H-MRSI - Methods and applications. Anal Biochem 2017; 529:48-64. [PMID: 28034791 DOI: 10.1016/j.ab.2016.12.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 12/16/2016] [Accepted: 12/23/2016] [Indexed: 12/27/2022]
Abstract
This article reviews the methodological aspects of detecting low-abundant J-coupled metabolites via 1D spectral editing techniques and 2D nuclear magnetic resonance (NMR) methods applied in vivo, in humans, with a focus on the brain. A brief explanation of the basics of J-evolution will be followed by an introduction to 1D spectral editing techniques (e.g., J-difference editing, multiple quantum coherence filtering) and 2D-NMR methods (e.g., correlation spectroscopy, J-resolved spectroscopy). Established and recently developed methods will be discussed and the most commonly edited J-coupled metabolites (e.g., neurotransmitters, antioxidants, onco-markers, and markers for metabolic processes) will be briefly summarized along with their most important applications in neuroscience and clinical diagnosis.
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Affiliation(s)
- Wolfgang Bogner
- High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, Vienna, Austria.
| | - Gilbert Hangel
- High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University Vienna, Vienna, Austria.
| | - Morteza Esmaeili
- Department of Circulation and Medical Imaging, NTNU, Norwegian University of Science and Technology, Trondheim, Norway; Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Ovidiu C Andronesi
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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156
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Quantum-mechanical simulations for in vivo MR spectroscopy: Principles and possibilities demonstrated with the program NMRScopeB. Anal Biochem 2017; 529:79-97. [DOI: 10.1016/j.ab.2016.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 08/24/2016] [Accepted: 10/07/2016] [Indexed: 11/19/2022]
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157
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Activation induced changes in GABA: Functional MRS at 7T with MEGA-sLASER. Neuroimage 2017; 156:207-213. [PMID: 28533117 DOI: 10.1016/j.neuroimage.2017.05.044] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/16/2017] [Accepted: 05/19/2017] [Indexed: 11/23/2022] Open
Abstract
Functional magnetic resonance spectroscopy (fMRS) has been used to assess the dynamic metabolic responses of the brain to a physiological stimulus non-invasively. However, only limited information on the dynamic functional response of γ-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain, is available. We aimed to measure the activation-induced changes in GABA unambiguously using a spectral editing method, instead of the conventional direct detection techniques used in previous fMRS studies. The Mescher-Garwood-semi-localised by adiabatic selective refocusing (MEGA-sLASER) sequence was developed at 7T to obtain the time course of GABA concentration without macromolecular contamination. A significant decrease (-12±5%) in the GABA to total creatine ratio (GABA/tCr) was observed in the motor cortex during a period of 10min of hand-clenching, compared to an initial baseline level (GABA/tCr =0.11±0.02) at rest. An increase in the Glx (glutamate and glutamine) to tCr ratio was also found, which is in agreement with previous findings. In contrast, no significant changes in NAA/tCr and tCr were detected. With consistent and highly efficient editing performance for GABA detection and the advantage of visually identifying GABA resonances in the spectra, MEGA-sLASER is demonstrated to be an effective method for studying of dynamic changes in GABA at 7T.
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158
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Manias K, Gill SK, Zarinabad N, Davies P, English M, Ford D, MacPherson L, Nicklaus-Wollenteit I, Oates A, Solanki G, Adamski J, Wilson M, Peet AC. Evaluation of the added value of 1H-magnetic resonance spectroscopy for the diagnosis of pediatric brain lesions in clinical practice. Neurooncol Pract 2017; 5:18-27. [PMID: 29692921 PMCID: PMC5909808 DOI: 10.1093/nop/npx005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background Magnetic resonance spectroscopy (MRS) aids noninvasive diagnosis of pediatric brain tumors, but use in clinical practice is not well documented. We aimed to review clinical use of MRS, establish added value in noninvasive diagnosis, and investigate potential impact on patient care. Methods Sixty-nine children with lesions imaged using MRS and reviewed by the tumor board from 2014 to 2016 met inclusion criteria. Contemporaneous MRI diagnosis, spectroscopy analysis, histopathology, and clinical information were reviewed. Final diagnosis was agreed on by the tumor board at study end. Results Five cases were excluded for lack of documented MRI diagnosis. The principal MRI diagnosis by pediatric radiologists was correct in 59%, increasing to 73% with addition of MRS. Of the 73%, 19.1% (95% CI, 9.1%-33.3%) were incorrectly diagnosed with MRI alone. MRS led to a significant improvement in correct diagnosis over all tumor types (P = .012). Of diagnoses correctly made with MRI, confidence increased by 37% when adding MRS, with no patients incorrectly re-diagnosed. Indolent lesions were diagnosed noninvasively in 85% of cases, with MRS a major contributor to 91% of these diagnoses. Of all patients, 39% were managed without histopathological diagnosis. MRS contributed to diagnosis in 68% of this group, modifying it in 12%. MRS influenced management in 33% of cases, mainly through avoiding and guiding biopsy and aiding tumor characterization. Conclusion MRS can improve accuracy and confidence in noninvasive diagnosis of pediatric brain lesions in clinical practice. There is potential to improve outcomes through avoiding biopsy of indolent lesions, aiding tumor characterization, and facilitating earlier family discussions and treatment planning.
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Affiliation(s)
- Karen Manias
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Pediatric Oncology, Birmingham Children's Hospital, Birmingham, UK
| | - Simrandip K Gill
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Pediatric Oncology, Birmingham Children's Hospital, Birmingham, UK
| | - Niloufar Zarinabad
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Paul Davies
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - Martin English
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Pediatric Oncology, Birmingham Children's Hospital, Birmingham, UK
| | - Daniel Ford
- Department of Clinical Oncology, Queen Elizabeth Hospital, Birmingham, UK
| | - Lesley MacPherson
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Radiology, Birmingham Children's Hospital, Birmingham, UK
| | - Ina Nicklaus-Wollenteit
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Histopathology, Birmingham Children's Hospital, Birmingham, UK
| | - Adam Oates
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Radiology, Birmingham Children's Hospital, Birmingham, UK
| | - Guirish Solanki
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Neurosurgery, Birmingham Children's Hospital, Birmingham, UK
| | - Jenny Adamski
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Pediatric Oncology, Birmingham Children's Hospital, Birmingham, UK
| | - Martin Wilson
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,School of Psychology, University of Birmingham, Birmingham, UK
| | - Andrew C Peet
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK.,Department of Pediatric Oncology, Birmingham Children's Hospital, Birmingham, UK
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159
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Wyss PO, Hock A, Kollias S. The Application of Human Spinal Cord Magnetic Resonance Spectroscopy to Clinical Studies: A Review. Semin Ultrasound CT MR 2017; 38:153-162. [DOI: 10.1053/j.sult.2016.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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160
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Harris AD, Saleh MG, Edden RAE. Edited 1 H magnetic resonance spectroscopy in vivo: Methods and metabolites. Magn Reson Med 2017; 77:1377-1389. [PMID: 28150876 PMCID: PMC5352552 DOI: 10.1002/mrm.26619] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/30/2016] [Accepted: 12/30/2016] [Indexed: 12/13/2022]
Abstract
The Proton magnetic resonance (1 H-MRS) spectrum contains information about the concentration of tissue metabolites within a predefined region of interest (a voxel). The conventional spectrum in some cases obscures information about less abundant metabolites due to limited separation and complex splitting of the metabolite peaks. One method to detect these metabolites is to reduce the complexity of the spectrum using editing. This review provides an overview of the one-dimensional editing methods available to interrogate these obscured metabolite peaks. These methods include sequence optimizations, echo-time averaging, J-difference editing methods (single BASING, dual BASING, and MEGA-PRESS), constant-time PRESS, and multiple quantum filtering. It then provides an overview of the brain metabolites whose detection can benefit from one or more of these editing approaches, including ascorbic acid, γ-aminobutyric acid, lactate, aspartate, N-acetyl aspartyl glutamate, 2-hydroxyglutarate, glutathione, glutamate, glycine, and serine. Magn Reson Med 77:1377-1389, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Ashley D Harris
- Department of Radiology, University of Calgary, Calgary, AB T2N 1N4, Canada
- Child and Adolescent Imaging Research (CAIR) Program, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T3B 6A9, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Muhammad G Saleh
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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161
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Aitouche Y, Gibbs SA, Gilbert G, Boucher O, Bouthillier A, Nguyen DK. Proton MR Spectroscopy in Patients with Nonlesional Insular Cortex Epilepsy Confirmed by Invasive EEG Recordings. J Neuroimaging 2017; 27:517-523. [PMID: 28318128 DOI: 10.1111/jon.12436] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 02/10/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Recent studies suggest that a nonnegligible proportion of drug-resistant epilepsy surgery candidates have an epileptogenic zone that involves the insula. We aimed to examine the value of proton magnetic resonance spectroscopy (1 H-MRS) in identifying patients with insular cortex epilepsy. METHODS Patients with possible nonlesional drug-refractory insular epilepsy underwent a voxel-based 1 H-MRS study prior to an intracranial electroencephalographic (EEG) study. Patients were then divided into two groups based on invasive EEG findings: the insular group with evidence of insular seizures and the noninsular group with no evidence of insular seizures. Sixteen age-matched healthy controls were also scanned for normative data. RESULTS Twenty-two epileptic patients were recruited, 12 with insular seizures and 10 with extra-insular seizures. Ipsilateral and contralateral insular N-acetyl-aspartate concentrations ([NAA]) and NAA/Cr ratios were found to be similar in both patient groups. No significant differences in [NAA] or NAA/Cr ratios were found between the insular group, noninsular group, and healthy controls. [NAA] and NAA/Cr asymmetry indices correctly lateralized the seizure focus in only 16.7% and 0% of patients, respectively. CONCLUSIONS Our preliminary findings suggest that 1 H-MRS fares poorly in identifying patients with nonlesional insular epilepsy.
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Affiliation(s)
| | - Steve A Gibbs
- Department of Neurosciences, Université de Montréal, Canada.,Division of Neurology, Hôpital du Sacré-Cœur de Montréal, Université de Montréal, Canada
| | - Guillaume Gilbert
- MR Clinical Science, Philips Healthcare, Canada.,Department of Radiology, CHUM Notre-Dame, Université de Montréal, Canada
| | | | - Alain Bouthillier
- Division of Neurosurgery, CHUM Notre-Dame, Université de Montréal, Canada
| | - Dang Khoa Nguyen
- Department of Neurosciences, Université de Montréal, Canada.,Division of Neurology, CHUM Notre-Dame, Université de Montréal, Canada
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162
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3T hippocampal glutamate-glutamine complex reflects verbal memory decline in aging. Neurobiol Aging 2017; 54:103-111. [PMID: 28363111 DOI: 10.1016/j.neurobiolaging.2017.01.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/05/2016] [Accepted: 01/06/2017] [Indexed: 12/19/2022]
Abstract
The hippocampus is a critical site for alterations that are responsible for age-related changes in memory. Here, we present a relatively novel approach of examining the relationship between memory performance and glutamate-glutamine levels using short echo time magnetic resonance spectroscopy. Specifically, we investigated the relationship between Glx (a composite of glutamate and glutamine) levels in the hippocampus, performance on a word-recall task, and resting-state functional connectivity. While there was no overall difference in Glx intensity between young and aging adults, we identified a positive correlation between delayed word-list recall and Glx, bilaterally in older adults, but not in young adults. Collapsed across age, we also discovered a negative relationship between Glx intensity and resting-state functional connectivity between the anterior hippocampus and regions in the subcallosal gyrus. These findings demonstrate the possible utility of Glx in identifying age-related changes in the brain and behavior and provide encouragement that magnetic resonance spectroscopy can be useful in predicting age-related decline before any physical abnormalities are present.
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163
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Grech-Sollars M, Vaqas B, Thompson G, Barwick T, Honeyfield L, O'Neill K, Waldman AD. An MRS- and PET-guided biopsy tool for intraoperative neuronavigational systems. J Neurosurg 2017:1-7. [PMID: 28306418 DOI: 10.3171/2016.7.jns16106.test] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Glioma heterogeneity and the limitations of conventional structural MRI for identifying aggressive tumor components can limit the reliability of stereotactic biopsy and, hence, tumor characterization, which is a hurdle for developing and selecting effective treatment strategies. In vivo MR spectroscopy (MRS) and PET enable noninvasive imaging of cellular metabolism relevant to proliferation and can detect regions of more highly active tumor. Here, the authors integrated presurgical PET and MRS with intraoperative neuronavigation to guide surgical biopsy and tumor sampling of brain gliomas with the aim of improving intraoperative tumor-tissue characterization and imaging biomarker validation. METHODS A novel intraoperative neuronavigation tool was developed as part of a study that aimed to sample high-choline tumor components identified by multivoxel MRS and 18F-methylcholine PET-CT. Spatially coregistered PET and MRS data were integrated into structural data sets and loaded onto an intraoperative neuronavigation system. High and low choline uptake/metabolite regions were represented as color-coded hollow spheres for targeted stereotactic biopsy and tumor sampling. RESULTS The neurosurgeons found the 3D spherical targets readily identifiable on the interactive neuronavigation system. In one case, areas of high mitotic activity were identified on the basis of high 18F-methylcholine uptake and elevated choline ratios found with MRS in an otherwise low-grade tumor, which revealed the possible use of this technique for tumor characterization. CONCLUSIONS These PET and MRI data can be combined and represented usefully for the surgeon in neuronavigation systems. This method enables neurosurgeons to sample tumor regions based on physiological and molecular imaging markers. The technique was applied for characterizing choline metabolism using MRS and 18F PET; however, this approach provides proof of principle for using different radionuclide tracers and other MRI methods, such as MR perfusion and diffusion.
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Affiliation(s)
- Matthew Grech-Sollars
- Departments of 1 Imaging and
- Division of Brain Sciences, Imperial College London; and
| | - Babar Vaqas
- Neurosurgery, Imperial College Healthcare NHS Trust
| | - Gerard Thompson
- Department of Neuroradiology, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Tara Barwick
- Departments of 1 Imaging and
- Department of Surgery and Cancer, and
| | | | | | - Adam D Waldman
- Departments of 1 Imaging and
- Division of Brain Sciences, Imperial College London; and
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164
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Global brain atrophy and metabolic dysfunction in LGI1 encephalitis: A prospective multimodal MRI study. J Neurol Sci 2017; 376:159-165. [PMID: 28431605 DOI: 10.1016/j.jns.2017.03.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/19/2017] [Accepted: 03/14/2017] [Indexed: 02/03/2023]
Abstract
BACKGROUND Chronic cognitive deficits are frequent in leucin-rich glioma-inactivated 1 protein (LGI1) encephalitis. We examined structural and metabolic brain abnormalities following LGI1 encephalitis and correlated findings with acute and follow-up clinical outcomes. METHODS Nine patients underwent prospective multimodal 3 Tesla MRI 33.1±18months after disease onset, including automated volumetry, diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). Data were compared to 9 age- and sex-matched healthy controls. RESULTS Although extratemporal lesions were not present on MRI in the acute stage, tract-based spatial statistics analyses of DTI during follow-up showed widespread changes in the cerebral and cerebellar white matter (WM), most prominent in the anterior parts of the corona radiata, capsula interna and corpus callosum. MRS revealed lower glutamine/glutamate WM levels compared to controls. Higher cerebellar gray matter volume was associated with better function at disease onset (measured by the modified Rankin Scale), and higher putaminal volume was associated with better cognition by Addenbrooke's Cognitive Examination test at 23.4±7.6months. CONCLUSIONS Poor clinical outcome following LGI1 encephalitis is associated with global brain atrophy and disintegration of white matter tracts. The pathological changes affect not only temporomesial structures but also frontal lobes and the cerebellum.
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165
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Jabłoński M, Starčuková J, Starčuk Z. Processing tracking in jMRUI software for magnetic resonance spectra quantitation reproducibility assurance. BMC Bioinformatics 2017; 18:56. [PMID: 28114896 PMCID: PMC5260066 DOI: 10.1186/s12859-017-1459-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 01/03/2017] [Indexed: 11/11/2022] Open
Abstract
Background Proton magnetic resonance spectroscopy is a non-invasive measurement technique which provides information about concentrations of up to 20 metabolites participating in intracellular biochemical processes. In order to obtain any metabolic information from measured spectra a processing should be done in specialized software, like jMRUI. The processing is interactive and complex and often requires many trials before obtaining a correct result. This paper proposes a jMRUI enhancement for efficient and unambiguous history tracking and file identification. Results A database storing all processing steps, parameters and files used in processing was developed for jMRUI. The solution was developed in Java, authors used a SQL database for robust storage of parameters and SHA-256 hash code for unambiguous file identification. The developed system was integrated directly in jMRUI and it will be publically available. A graphical user interface was implemented in order to make the user experience more comfortable. The database operation is invisible from the point of view of the common user, all tracking operations are performed in the background. Conclusions The implemented jMRUI database is a tool that can significantly help the user to track the processing history performed on data in jMRUI. The created tool is oriented to be user-friendly, robust and easy to use. The database GUI allows the user to browse the whole processing history of a selected file and learn e.g. what processing lead to the results, where the original data are stored, to obtain the list of all processing actions performed on spectra.
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Affiliation(s)
- Michał Jabłoński
- Institute of Scientific Instruments of the CAS, Královopolská 147, 612 64, Brno, Czech Republic. .,Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37, Brno, Czech Republic.
| | - Jana Starčuková
- Institute of Scientific Instruments of the CAS, Královopolská 147, 612 64, Brno, Czech Republic
| | - Zenon Starčuk
- Institute of Scientific Instruments of the CAS, Královopolská 147, 612 64, Brno, Czech Republic
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166
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Das D, Coello E, Schulte RF, Menze BH. Quantification of Metabolites in Magnetic Resonance Spectroscopic Imaging Using Machine Learning. MEDICAL IMAGE COMPUTING AND COMPUTER ASSISTED INTERVENTION − MICCAI 2017 2017. [DOI: 10.1007/978-3-319-66179-7_53] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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167
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Grech-Sollars M, Vaqas B, Thompson G, Barwick T, Honeyfield L, O'Neill K, Waldman AD. An MRS- and PET-guided biopsy tool for intraoperative neuronavigational systems. J Neurosurg 2016; 127:812-818. [PMID: 27834593 DOI: 10.3171/2016.7.jns16106] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE Glioma heterogeneity and the limitations of conventional structural MRI for identifying aggressive tumor components can limit the reliability of stereotactic biopsy and, hence, tumor characterization, which is a hurdle for developing and selecting effective treatment strategies. In vivo MR spectroscopy (MRS) and PET enable noninvasive imaging of cellular metabolism relevant to proliferation and can detect regions of more highly active tumor. Here, the authors integrated presurgical PET and MRS with intraoperative neuronavigation to guide surgical biopsy and tumor sampling of brain gliomas with the aim of improving intraoperative tumor-tissue characterization and imaging biomarker validation. METHODS A novel intraoperative neuronavigation tool was developed as part of a study that aimed to sample high-choline tumor components identified by multivoxel MRS and 18F-methylcholine PET-CT. Spatially coregistered PET and MRS data were integrated into structural data sets and loaded onto an intraoperative neuronavigation system. High and low choline uptake/metabolite regions were represented as color-coded hollow spheres for targeted stereotactic biopsy and tumor sampling. RESULTS The neurosurgeons found the 3D spherical targets readily identifiable on the interactive neuronavigation system. In one case, areas of high mitotic activity were identified on the basis of high 18F-methylcholine uptake and elevated choline ratios found with MRS in an otherwise low-grade tumor, which revealed the possible use of this technique for tumor characterization. CONCLUSIONS These PET and MRI data can be combined and represented usefully for the surgeon in neuronavigation systems. This method enables neurosurgeons to sample tumor regions based on physiological and molecular imaging markers. The technique was applied for characterizing choline metabolism using MRS and 18F PET; however, this approach provides proof of principle for using different radionuclide tracers and other MRI methods, such as MR perfusion and diffusion.
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Affiliation(s)
- Matthew Grech-Sollars
- Departments of 1 Imaging and.,Division of Brain Sciences, Imperial College London; and
| | - Babar Vaqas
- Neurosurgery, Imperial College Healthcare NHS Trust
| | - Gerard Thompson
- Department of Neuroradiology, Salford Royal NHS Foundation Trust, Salford, United Kingdom
| | - Tara Barwick
- Departments of 1 Imaging and.,Department of Surgery and Cancer, and
| | | | | | - Adam D Waldman
- Departments of 1 Imaging and.,Division of Brain Sciences, Imperial College London; and
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168
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Dalko E, Genete D, Auger F, Dovergne C, Lambert C, Herbert F, Cazenave PA, Roland J, Pied S. Heme dampens T-cell sequestration by modulating glial cell responses during rodent cerebral malaria. Brain Behav Immun 2016; 58:280-290. [PMID: 27477919 DOI: 10.1016/j.bbi.2016.07.157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 07/21/2016] [Accepted: 07/27/2016] [Indexed: 01/24/2023] Open
Abstract
Cerebral malaria is the deadliest complication of Plasmodium falciparum infection. Its pathophysiology is associated with a strong pro-inflammatory reaction and the activation of glial cells. Among modulators released during the infection, heme seems to play a controversial role in the pathophysiology of malaria. Herein, we first investigated the phenotype of glial cells during cerebral malaria in C57BL/6 mice infected with P. berghei ANKA. Given the fact that high levels of heme were associated with cerebral malaria, we then investigated its impact on microglial, astrocyte, and T cell responses to further clarify its contribution in the neuropathophysiology. Surprisingly, we found that administration of heme twice a day from day three of infection induced the expression of the Heme oxygenase-1 (Hmox1) gene and prevented brain damages. More specifically, heme inhibited the M1 phenotype of microglia, hampered the activation of astrocytes, and decreased the cerebral expression of Ifng, Tnfa and Ip10. Heme might that way alter the migration of pathogenic CD4 and CD8 T lymphocytes within the brain observed during cerebral malaria. Taking into account that cerebral malaria results from a complex interplay between host- and parasite-derived factors, it is possible that genetic polymorphisms of Hmox1, which could be associated with the control of systemic levels of heme during P. falciparum infection, might explain its dual role and its contribution to the resistance to cerebral malaria.
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Affiliation(s)
- Esther Dalko
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France; Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Canada
| | - Delphine Genete
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Florent Auger
- Imaging Platform, Research Pole, Lille University Hospital, Lille, France; Université de Lille, UDSL, EA 1046 Lille, France
| | - Claire Dovergne
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Claire Lambert
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Fabien Herbert
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Pierre-André Cazenave
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Jacques Roland
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France
| | - Sylviane Pied
- Center for Infection and Immunity of Lille, CNRS UMR 8204, Université de Lille, Institut Pasteur de Lille, Lille, France.
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169
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Xin L, Tkáč I. A practical guide to in vivo proton magnetic resonance spectroscopy at high magnetic fields. Anal Biochem 2016; 529:30-39. [PMID: 27773654 DOI: 10.1016/j.ab.2016.10.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 10/03/2016] [Accepted: 10/19/2016] [Indexed: 12/26/2022]
Abstract
Localized proton magnetic resonance spectroscopy (1H-MRS) is a noninvasive tool for measuring in vivo neurochemical information in animal and human brains. With the increase of magnetic field strength, whereas localized 1H-MRS benefits from higher sensitivity and spectral dispersion, it is challenged by increased spatial inhomogeneity of the B0 and B1 fields, larger chemical shift displacement error, and shortened T2 relaxation times of metabolites. Advanced localized 1H-MRS methodologies developed for high magnetic fields have shown promising results and allow the measurement of neurochemical profiles with up to 19 brain metabolites, including less-abundant metabolites, such as glutathione, glycine, γ-aminobutyric acid and ascorbate. To provide a practical guide for conducting in vivo1H-MRS studies at high magnetic field strength, we reviewed various essential technical aspects from data acquisition (hardware requirements, B1 and B0 inhomogeneity, water suppression, localization sequences and acquisition strategies) to data processing (frequency and phase correction, spectral quality control, spectral fitting and concentration referencing). Additionally, we proposed guidelines for choosing the most appropriate data acquisition and processing approaches to maximize the achievable neurochemical information.
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Affiliation(s)
- Lijing Xin
- Animal Imaging and Technology Core (AIT), Center for Biomedical Imaging (CIBM), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
| | - Ivan Tkáč
- Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
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170
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Hone-Blanchet A, Edden RA, Fecteau S. Online Effects of Transcranial Direct Current Stimulation in Real Time on Human Prefrontal and Striatal Metabolites. Biol Psychiatry 2016; 80:432-438. [PMID: 26774968 PMCID: PMC5512102 DOI: 10.1016/j.biopsych.2015.11.008] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 11/11/2015] [Accepted: 11/13/2015] [Indexed: 11/17/2022]
Abstract
BACKGROUND Studies have reported that transcranial direct current stimulation (tDCS) can modulate human behaviors, symptoms, and neural activity; however, the neural effects during stimulation are unknown. Most studies compared the effects of tDCS before and after stimulation. The objective of our study was to measure the neurobiological effect of a single tDCS dose during stimulation. METHODS We conducted an online and offline protocol combining tDCS and magnetic resonance spectroscopy (MRS) in 17 healthy participants. We applied anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC) and cathodal tDCS over the right DLPFC for 30 minutes, one of the most common montages used with tDCS. We collected MRS measurements in the left DLPFC and left striatum during tDCS and an additional MRS measurement in the left DLPFC immediately after the end of stimulation. RESULTS During stimulation, active tDCS, as compared with sham tDCS, elevated prefrontal N-acetylaspartate and striatal glutamate + glutamine but did not induce significant differences in prefrontal or striatal gamma-aminobutyric acid level. Immediately after stimulation, active tDCS, as compared with sham tDCS, did not significantly induce differences in glutamate + glutamine, N-acetylaspartate, or gamma-aminobutyric acid levels in the left DLPFC. CONCLUSIONS These observations indicate that tDCS over the DLPFC has fast excitatory effects, acting on prefrontal and striatal transmissions, and these effects are short lived. One may postulate that repeated sessions of tDCS might induce similar longer lasting effects of elevated prefrontal N-acetylaspartate and striatal glutamate + glutamine levels, which may contribute to its behavioral and clinical effects.
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Affiliation(s)
| | | | - Shirley Fecteau
- Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale, Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Faculté de médecine, Université Laval, Quebec City, Quebec, Canada; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts..
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171
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Rowland BC, Liao H, Adan F, Mariano L, Irvine J, Lin AP. Correcting for Frequency Drift in Clinical Brain MR Spectroscopy. J Neuroimaging 2016; 27:23-28. [PMID: 27601075 DOI: 10.1111/jon.12388] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 07/22/2016] [Accepted: 07/24/2016] [Indexed: 11/28/2022] Open
Abstract
PURPOSE Averaging multiple repetitions to improve signal-to-noise ratio is common practice in magnetic resonance spectroscopy (MRS). However, temporal variations in scanner B0 due to motion or gradient heating may cause spectra to become misaligned, broadening and distorting peaks and impacting on processing and quantification. We present a comparison using in vivo data of different methods for correcting these errors. METHODS Three different correction methods were applied to 53 brain scans: residual water peak alignment, creatine fitting, and spectral registration. In 32 of 53 subjects, diffusion tensor imaging (DTI) was acquired prior to the MRS scan. We compared the resulting linewidths to find the most effective technique. In addition, the impact on metabolite concentration estimates was evaluated. RESULTS MRS data acquired after DTI imaging exhibited a frequency drift four times higher than data without DTI, resulting in changes to metabolite concentrations, particularly glutamate/glutamine. All three correction methods produced significantly improved linewidths relative to uncorrected data, with spectral registration performing best by a small margin. CONCLUSION Frequency correction is an important step in processing MRS data, significantly impacting metabolite quantification, particularly after echo-planar imaging that often occurs with MRS scans in clinical studies. Spectral registration proved most effective at frequency correction.
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Affiliation(s)
- Benjamin C Rowland
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Boston, MA
| | - Huijun Liao
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Boston, MA
| | - Fatah Adan
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Boston, MA
| | | | | | - Alexander P Lin
- Center for Clinical Spectroscopy, Department of Radiology, Brigham and Women's Hospital, Boston, MA
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172
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Scott J, Underwood J, Garvey LJ, Mora-Peris B, Winston A. A comparison of two post-processing analysis methods to quantify cerebral metabolites measured via proton magnetic resonance spectroscopy in HIV disease. Br J Radiol 2016; 89:20150979. [PMID: 26954329 DOI: 10.1259/bjr.20150979] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Non-invasive biomarkers to monitor cerebral function in treated human immunodeficiency virus (HIV) disease are required. Cerebral metabolite ratios (CMRs) measured by proton-MR spectroscopy ((1)H-MRS) are a potential biomarker. Here, we compare two post-processing software packages to quantify CMRs. METHODS Cerebral (1)H-MRS data from 11 HIV-positive subjects before and after antiretroviral therapy intensification with maraviroc were quantified using a java-based version of the MR user interface package (jMRUI) and the totally automatic robust quantitation in nuclear MR (TARQUIN). (1)H-MRS data included N-acetylaspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mI) from three cerebral locations. Differences in quantification and clinical associations of CMRs measured by the two packages were evaluated. RESULTS Mean CMRs were generally lower when measured by TARQUIN than by jMRUI (NAA/Cr, Cho/Cr, mI/Cr ratios of 1.78, 0.83, 0.81 for jMRUI, and 1.27, 0.25, 0.81 for TARQUIN). Longitudinal changes were observed in CMRs in the basal ganglia voxel although these changes were not statistically significant [+7.1% (p = 0.18), +0.0% (p = 0.91) and -6.6% (p = 0.61) and +14.8% (p = 0.18), +17.9% (p = 0.07) and +34.8% (p = 0.17) for NAA/Cr, Cho/Cr and mI/Cr ratios measured by TARQUIN and jMRUI, respectively]. Plasma maraviroc concentration was associated with a decrease in mI/Cr ratio measured via TARQUIN (p = 0.049). CONCLUSION Although CMRs differed when quantified by jMRUI vs TARQUIN, these differences were consistently observed across three cerebral locations, and clinical associations were evident by both methods. ADVANCES IN KNOWLEDGE TARQUIN and jMRUI are viable options to use in the post-processing of cerebral MRS data acquired in HIV disease.
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Affiliation(s)
- Joseph Scott
- Division of Infectious Diseases, Winston Churchill Wing, St Mary's Campus, Imperial College, London, UK
| | - Jonathan Underwood
- Division of Infectious Diseases, Winston Churchill Wing, St Mary's Campus, Imperial College, London, UK
| | - Lucy J Garvey
- Division of Infectious Diseases, Winston Churchill Wing, St Mary's Campus, Imperial College, London, UK
| | - Borja Mora-Peris
- Division of Infectious Diseases, Winston Churchill Wing, St Mary's Campus, Imperial College, London, UK
| | - Alan Winston
- Division of Infectious Diseases, Winston Churchill Wing, St Mary's Campus, Imperial College, London, UK
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173
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Brown GC, Cowin GJ, Galloway GJ. A USPIO doped gel phantom for R2* relaxometry. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 30:15-27. [PMID: 27435747 DOI: 10.1007/s10334-016-0576-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/03/2016] [Accepted: 06/20/2016] [Indexed: 01/19/2023]
Abstract
OBJECTIVE This work describes a phantom containing regions of controlled R2* (1/T2*) values to provide a stable reference object for testing implementations of R2* relaxometry commonly used for liver and heart iron assessments. MATERIALS AND METHODS A carrageenan-strengthened gadolinium DTPA doped agarose gel was used to enclose nine gels additionally doped with ultra-small superparamagnetic iron oxide. R2* values were determined at 1.5 T using multi-echo GRE sequences and exponential regression of pixel values from a region of interest against echo time using non-linear regression algorithms. We measured R2*, R2 and R1 values and the inter-scan and inter-operator reproducibility. RESULTS The phantom reliably demonstrated R2* values in seven steps between 22.4 s-1 (SE 1.98) and 441.9 s-1 (SE 6.76), with an R2* relaxivity (r2*) of 792 (SE 5.6) mM-1 s-1. The doped gels displayed a concentration-dependent R2' component of R2* phantom, indicating superparamagnetic enhancement effects. We observed no significant change in relaxivity (r2*) over 12 months, and estimate a useful life of 3 years. Detailed descriptions of the production process and calculators are been provided as Online Resources. CONCLUSION The phantom provides a durable test object with controlled R2* relaxation behaviour, useful for a range of R2* relaxometry reference work.
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Affiliation(s)
- Gregory C Brown
- Centre for Advanced Imaging, The University of Queensland, Building 57, St Lucia, QLD, 4072, Australia.
| | - Gary J Cowin
- Centre for Advanced Imaging, The University of Queensland, Building 57, St Lucia, QLD, 4072, Australia
| | - Graham J Galloway
- Translational Research Centre, The University of Queensland, St Lucia, Australia
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174
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Zarinabad N, Wilson M, Gill SK, Manias KA, Davies NP, Peet AC. Multiclass imbalance learning: Improving classification of pediatric brain tumors from magnetic resonance spectroscopy. Magn Reson Med 2016; 77:2114-2124. [PMID: 27404900 PMCID: PMC5484359 DOI: 10.1002/mrm.26318] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 05/24/2016] [Accepted: 05/31/2016] [Indexed: 11/24/2022]
Abstract
Purpose Classification of pediatric brain tumors from 1H‐magnetic resonance spectroscopy (MRS) can aid diagnosis and management of brain tumors. However, varied incidence of the different tumor types leads to imbalanced class sizes and introduces difficulties in classifying rare tumor groups. This study assessed different imbalanced multiclass learning techniques and compared the use of complete spectra and quantified metabolite profiles for classification of three main childhood brain tumor types. Methods Single‐voxel, Short echo time MRS data were collected from 90 patients with pilocytic astrocytoma (n = 42), medulloblastoma (n = 38), or ependymoma (n = 10). Both spectra and metabolite profiles were used to develop the learning algorithms. The borderline synthetic minority oversampling technique and AdaboostM1 were used to correct for the skewed distribution. Classifiers were trained using five different pattern recognition algorithms. Results Use of imbalanced learning techniques improved the balanced accuracy rate (BAR) of all classification methods (average BAR over all classification methods for spectra: oversampled data = 0.81, original = 0.63, P < 0.001; metabolite concentration: oversampled‐data = 0.91, original = 0.75, P < 0.0001). Performance of all classifiers in discriminating ependymomas increased when oversampled data were used compared with original data for both complete spectra (F‐measure P < 0.01) and metabolite profile (F‐measure P < 0.001). Conclusion Imbalanced learning techniques improve the classification accuracy of childhood brain tumors from MRS where group sizes differ and facilitate the inclusion of rarer tumor types into clinical decision support systems. Magn Reson Med 77:2114–2124, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Niloufar Zarinabad
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom
| | - Martin Wilson
- School of Psychology and Birmingham University Imaging Centre, University of Birmingham, Edgbaston, Birmingham United Kingdom
| | - Simrandip K Gill
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom
| | - Karen A Manias
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom
| | - Nigel P Davies
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom.,Department of Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Andrew C Peet
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, United Kingdom.,Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom
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175
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Pascente R, Frigerio F, Rizzi M, Porcu L, Boido M, Davids J, Zaben M, Tolomeo D, Filibian M, Gray WP, Vezzani A, Ravizza T. Cognitive deficits and brain myo-Inositol are early biomarkers of epileptogenesis in a rat model of epilepsy. Neurobiol Dis 2016; 93:146-55. [PMID: 27173096 DOI: 10.1016/j.nbd.2016.05.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/26/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022] Open
Abstract
One major unmet clinical need in epilepsy is the identification of therapies to prevent or arrest epilepsy development in patients exposed to a potential epileptogenic insult. The development of such treatments has been hampered by the lack of non-invasive biomarkers that could be used to identify the patients at-risk, thereby allowing to design affordable clinical studies. Our goal was to test the predictive value of cognitive deficits and brain astrocyte activation for the development of epilepsy following a potential epileptogenic injury. We used a model of epilepsy induced by pilocarpine-evoked status epilepticus (SE) in 21-day old rats where 60-70% of animals develop spontaneous seizures after around 70days, although SE is similar in all rats. Learning was evaluated in the Morris water-maze at days 15 and 65 post-SE, each time followed by proton magnetic resonance spectroscopy for measuring hippocampal myo-Inositol levels, a marker of astrocyte activation. Rats were video-EEG monitored for two weeks at seven months post-SE to detect spontaneous seizures, then brain histology was done. Behavioral and imaging data were retrospectively analysed in epileptic rats and compared with non-epileptic and control animals. Rats displayed spatial learning deficits within three weeks from SE. However, only epilepsy-prone rats showed accelerated forgetting and reduced learning rate compared to both rats not developing epilepsy and controls. These deficits were associated with reduced hippocampal neurogenesis. myo-Inositol levels increased transiently in the hippocampus of SE-rats not developing epilepsy while this increase persisted until spontaneous seizures onset in epilepsy-prone rats, being associated with a local increase in S100β-positive astrocytes. Neuronal cell loss was similar in all SE-rats. Our data show that behavioral deficits, together with a non-invasive marker of astrocyte activation, predict which rats develop epilepsy after an acute injury. These measures have potential clinical relevance for identifying individuals at-risk for developing epilepsy following exposure to epileptogenic insults, and consequently, for designing adequately powered antiepileptogenesis trials.
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Affiliation(s)
- Rosaria Pascente
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Federica Frigerio
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Massimo Rizzi
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Luca Porcu
- Department of Oncology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Marina Boido
- Neuroscience Institute "Cavalieri Ottolenghi", Department of Neuroscience, University of Torino, Torino, Italy
| | - Joe Davids
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | - Malik Zaben
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | - Daniele Tolomeo
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Marta Filibian
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - William P Gray
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, UK
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy
| | - Teresa Ravizza
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milano, Italy.
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Starobinets O, Korn N, Iqbal S, Noworolski SM, Zagoria R, Kurhanewicz J, Westphalen AC. Practical aspects of prostate MRI: hardware and software considerations, protocols, and patient preparation. Abdom Radiol (NY) 2016; 41:817-30. [PMID: 27193785 DOI: 10.1007/s00261-015-0590-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The use of multiparametric MRI scans for the evaluation of men with prostate cancer has increased dramatically and is likely to continue expanding as new developments come to practice. However, it has not yet gained the same level of acceptance of other imaging tests. Partly, this is because of the use of suboptimal protocols, lack of standardization, and inadequate patient preparation. In this manuscript, we describe several practical aspects of prostate MRI that may facilitate the implementation of new prostate imaging programs or the expansion of existing ones.
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Affiliation(s)
- Olga Starobinets
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Natalie Korn
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Sonam Iqbal
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Susan M Noworolski
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Box 0946, San Francisco, CA, 94143, USA
| | - Ronald Zagoria
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, M372, Box 0628, San Francisco, CA, 94143, USA
| | - John Kurhanewicz
- Graduate Group of Bioengineering, Department of Radiology and Biomedical Imaging, University of California San Francisco, 1700 4th Street, Ste. 203, San Francisco, CA, 94158, USA
| | - Antonio C Westphalen
- Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, M372, Box 0628, San Francisco, CA, 94143, USA.
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177
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Chan KL, Puts NAJ, Schär M, Barker PB, Edden RAE. HERMES: Hadamard encoding and reconstruction of MEGA-edited spectroscopy. Magn Reson Med 2016; 76:11-9. [PMID: 27089868 DOI: 10.1002/mrm.26233] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 03/01/2016] [Accepted: 03/10/2016] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate a novel Hadamard-encoded spectral editing scheme and evaluate its performance in simultaneously quantifying N-acetyl aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG) at 3 Tesla. METHODS Editing pulses applied according to a Hadamard encoding scheme allow the simultaneous acquisition of multiple metabolites. The method, called HERMES (Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy), was optimized to detect NAA and NAAG simultaneously using density-matrix simulations and validated in phantoms at 3T. In vivo data were acquired in the centrum semiovale of 12 normal subjects. The NAA:NAAG concentration ratio was determined by modeling in vivo data using simulated basis functions. Simulations were also performed for potentially coedited molecules with signals within the detected NAA/NAAG region. RESULTS Simulations and phantom experiments show excellent segregation of NAA and NAAG signals into the intended spectra, with minimal crosstalk. Multiplet patterns show good agreement between simulations and phantom and in vivo data. In vivo measurements show that the relative peak intensities of the NAA and NAAG spectra are consistent with a NAA:NAAG concentration ratio of 4.22:1 in good agreement with literature. Simulations indicate some coediting of aspartate and glutathione near the detected region (editing efficiency: 4.5% and 78.2%, respectively, for the NAAG reconstruction and 5.1% and 19.5%, respectively, for the NAA reconstruction). CONCLUSION The simultaneous and separable detection of two otherwise overlapping metabolites using HERMES is possible at 3T. Magn Reson Med 76:11-19, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Kimberly L Chan
- Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nicolaas A J Puts
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael Schär
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Peter B Barker
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Richard A E Edden
- F. M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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178
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Ford TC, Crewther DP. A Comprehensive Review of the (1)H-MRS Metabolite Spectrum in Autism Spectrum Disorder. Front Mol Neurosci 2016; 9:14. [PMID: 27013964 PMCID: PMC4783404 DOI: 10.3389/fnmol.2016.00014] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/16/2016] [Indexed: 01/11/2023] Open
Abstract
Neuroimaging studies of neuropsychiatric behavior biomarkers across spectrum disorders are typically based on diagnosis, thus failing to account for the heterogeneity of multi-dimensional spectrum disorders such as autism (ASD). Control group trait phenotypes are also seldom reported. Proton magnetic resonance spectroscopy (1H-MRS) measures the abundance of neurochemicals such as neurotransmitters and metabolites and hence can probe disorder phenotypes at clinical and sub-clinical levels. This detailed review summarizes and critiques the current 1H-MRS research in ASD. The literature reports reduced N-acetylaspartate (NAA), glutamate and glutamine (Glx), γ-aminobutyric acid (GABA), creatine and choline, and increased glutamate for children with ASD. Adult studies are few and results are inconclusive. Overall, the literature has several limitations arising from differences in 1H-MRS methodology and sample demographics. We argue that more consistent methods and greater emphasis on phenotype studies will advance understanding of underlying cortical metabolite disturbance in ASD, and the detection, diagnosis, and treatment of ASD and other multi-dimensional psychiatric disorders.
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Affiliation(s)
- Talitha C Ford
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
| | - David P Crewther
- Faculty of Health, Arts and Design, Centre for Human Psychopharmacology, Swinburne University of Technology Melbourne, VIC, Australia
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179
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Iqbal Z, Wilson NE, Thomas MA. 3D spatially encoded and accelerated TE-averaged echo planar spectroscopic imaging in healthy human brain. NMR IN BIOMEDICINE 2016; 29:329-339. [PMID: 26748673 DOI: 10.1002/nbm.3469] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
Several different pathologies, including many neurodegenerative disorders, affect the energy metabolism of the brain. Glutamate, a neurotransmitter in the brain, can be used as a biomarker to monitor these metabolic processes. One method that is capable of quantifying glutamate concentration reliably in several regions of the brain is TE-averaged (1) H spectroscopic imaging. However, this type of method requires the acquisition of multiple TE lines, resulting in long scan durations. The goal of this experiment was to use non-uniform sampling, compressed sensing reconstruction and an echo planar readout gradient to reduce the scan time by a factor of eight to acquire TE-averaged spectra in three spatial dimensions. Simulation of glutamate and glutamine showed that the 2.2-2.4 ppm spectral region contained 95% glutamate signal using the TE-averaged method. Peak integration of this spectral range and home-developed, prior-knowledge-based fitting were used for quantitation. Gray matter brain phantom measurements were acquired on a Siemens 3 T Trio scanner. Non-uniform sampling was applied retrospectively to these phantom measurements and quantitative results of glutamate with respect to creatine 3.0 (Glu/Cr) ratios showed a coefficient of variance of 16% for peak integration and 9% for peak fitting using eight-fold acceleration. In vivo scans of the human brain were acquired as well and five different brain regions were quantified using the prior-knowledge-based algorithm. Glu/Cr ratios from these regions agreed with previously reported results in the literature. The method described here, called accelerated TE-averaged echo planar spectroscopic imaging (TEA-EPSI), is a significant methodological advancement and may be a useful tool for categorizing glutamate changes in pathologies where affected brain regions are not known a priori. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Zohaib Iqbal
- Department of Radiological Sciences, University of California Los Angeles, USA
| | - Neil E Wilson
- Department of Radiological Sciences, University of California Los Angeles, USA
| | - M Albert Thomas
- Department of Radiological Sciences, University of California Los Angeles, USA
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180
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Cadenas-Sánchez C, Mora-González J, Migueles JH, Martín-Matillas M, Gómez-Vida J, Escolano-Margarit MV, Maldonado J, Enriquez GM, Pastor-Villaescusa B, de Teresa C, Navarrete S, Lozano RM, de Dios Beas-Jiménez J, Estévez-López F, Mena-Molina A, Heras MJ, Chillón P, Campoy C, Muñoz-Hernández V, Martínez-Ávila WD, Merchan ME, Perales JC, Gil Á, Verdejo-García A, Aguilera CM, Ruiz JR, Labayen I, Catena A, Ortega FB. An exercise-based randomized controlled trial on brain, cognition, physical health and mental health in overweight/obese children (ActiveBrains project): Rationale, design and methods. Contemp Clin Trials 2016; 47:315-24. [DOI: 10.1016/j.cct.2016.02.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 02/14/2016] [Accepted: 02/19/2016] [Indexed: 12/30/2022]
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181
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Recombinant Adeno Associated Viral (AAV) vector type 9 delivery of Ex1-Q138-mutant huntingtin in the rat striatum as a short-time model for in vivo studies in drug discovery. Neurobiol Dis 2016; 86:41-51. [DOI: 10.1016/j.nbd.2015.11.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 09/30/2015] [Accepted: 11/23/2015] [Indexed: 11/18/2022] Open
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182
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Birch R, Peet AC, Dehghani H, Wilson M. Influence of macromolecule baseline on 1 H MR spectroscopic imaging reproducibility. Magn Reson Med 2016; 77:34-43. [PMID: 26800478 PMCID: PMC5215417 DOI: 10.1002/mrm.26103] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 11/30/2015] [Accepted: 12/03/2015] [Indexed: 11/11/2022]
Abstract
Purpose Poorly characterized macromolecular (MM) and baseline artefacts are known to reduce metabolite quantitation accuracy in 1H MR spectroscopic imaging (MRSI). Increasing echo time (TE) and improvements in MM analysis schemes have both been proposed as strategies to improve metabolite measurement reliability. In this study, the influence of TE and two MM analysis schemes on MRSI reproducibility are investigated. Methods An experimentally acquired baseline was collected using an inversion recovery sequence (TI = 750 ms) and incorporated into the analysis method. Intrasubject reproducibility of MRSI scans, acquired at 3 Tesla, was assessed using metabolite coefficients of variance (COVs) for both experimentally acquired and simulated MM analysis schemes. In addition, the reproducibility of TE = 35 ms, 80 ms, and 144 ms was evaluated. Results TE = 80 ms was the most reproducible for singlet metabolites with COVs < 6% for total N‐acetyl‐aspartate, total creatine, and total choline; however, moderate multiplet dephasing was observed. Analysis incorporating the experimental baseline achieved higher Glu and Glx reproducibility at TE = 35 ms, and showed improvements over the simulated baseline, with higher efficacy for poorer data. Conclusion Overall, TE = 80 ms yielded the most reproducible singlet metabolite estimates. However, combined use of a short TE sequence and the experimental baseline may be preferred as a compromise between accuracy, multiplet dephasing, and T2 bias on metabolite estimates. Magn Reson Med 77:34–43, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Rebecca Birch
- PSIBS Doctoral Training Centre, University of Birmingham, United Kingdom.,Birmingham University Imaging Centre (BUIC), School of Psychology, University of Birmingham, United Kingdom
| | - Andrew C Peet
- Department of Oncology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom.,School of Cancer Sciences, University of Birmingham, United Kingdom
| | - Hamid Dehghani
- School of Computer Science, University of Birmingham, Kingdom
| | - Martin Wilson
- Birmingham University Imaging Centre (BUIC), School of Psychology, University of Birmingham, United Kingdom
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183
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Abstract
PURPOSE An enhanced version of the ProFit fitting tool was developed and validated to improve the quantification of two-dimensional JRPESS spectroscopic data. METHODS The proposed enhancements were achieved by flexible organization of prior knowledge, configurations for different situations, the inclusion of measured macromolecular baseline contribution, additional baseline splines and a model-free lineshape based on self-deconvolution. The new software was tested and tuned on simulated data and subsequently applied to in vivo intrasubject and intersubject data. RESULTS Fit results of simulated and acquired spectra show good overall quality suggesting the potential reliable detection of up to 18 metabolites on a 3T system yielding Cramer-Lower-Bounds below 20%. CONCLUSION The proposed enhanced version of ProFit together with two-dimensional J-resolved spectroscopy offers the opportunity to reliably detect a wide selection of important brain metabolites on 3T.
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Affiliation(s)
- Alexander Fuchs
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, ETH & University Zurich, Switzerland
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184
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Hollinshead KER, Williams DS, Tennant DA, Ludwig C. Probing Cancer Cell Metabolism Using NMR Spectroscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 899:89-111. [PMID: 27325263 DOI: 10.1007/978-3-319-26666-4_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Altered cellular metabolism is now accepted to be at the core of many diseases including cancer. Over the past 20 years, NMR has become a core technology to study these metabolic perturbations in detail. This chapter reviews current NMR-based methods for steady-state metabolism and, in particular, the use of non-radioactive stable isotope-enriched tracers. Opportunities and challenges for each method, such as 1D (1)H NMR spectroscopy and (13)C carbon-based NMR spectroscopic methods, are discussed. Ultimately, the combination of NMR and mass spectra as orthogonal technologies are required to compensate for the drawbacks of each technique when used singly are discussed.
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Affiliation(s)
- Kate E R Hollinshead
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Debbie S Williams
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK
| | - Christian Ludwig
- Institute of Metabolism and Systems Research, University of Birmingham, IBR, Edgbaston, Birmingham, B15 2TT, UK.
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185
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Simpson R, Devenyi GA, Jezzard P, Hennessy TJ, Near J. Advanced processing and simulation of
MRS
data using the
FID
appliance (
FID‐A
)—An open source,
MATLAB
‐based toolkit. Magn Reson Med 2015; 77:23-33. [DOI: 10.1002/mrm.26091] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 02/04/2023]
Affiliation(s)
- Robin Simpson
- Department of Radiology, Medical PhysicsFreiburg UniversityFreiburg Germany
| | - Gabriel A. Devenyi
- Centre d'Imagerie CérébraleDouglas Mental Health University InstituteMontreal Canada
| | - Peter Jezzard
- FMRIB Centre, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxford UK
| | - T. Jay Hennessy
- Centre d'Imagerie CérébraleDouglas Mental Health University InstituteMontreal Canada
- Department of Biomedical EngineeringMcGill UniversityMontreal Canada
| | - Jamie Near
- Centre d'Imagerie CérébraleDouglas Mental Health University InstituteMontreal Canada
- Department of Biomedical EngineeringMcGill UniversityMontreal Canada
- Department of PsychiatryMcGill UniversityMontreal Canada
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186
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Robertson CE, Ratai EM, Kanwisher N. Reduced GABAergic Action in the Autistic Brain. Curr Biol 2015; 26:80-5. [PMID: 26711497 DOI: 10.1016/j.cub.2015.11.019] [Citation(s) in RCA: 221] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 10/19/2015] [Accepted: 11/05/2015] [Indexed: 10/22/2022]
Abstract
An imbalance between excitatory/inhibitory neurotransmission has been posited as a central characteristic of the neurobiology of autism [1], inspired in part by the striking prevalence of seizures among individuals with the disorder [2]. Evidence supporting this hypothesis has specifically implicated the signaling pathway of the inhibitory neurotransmitter, γ-aminobutyric acid (GABA), in this putative imbalance: GABA receptor genes have been associated with autism in linkage and copy number variation studies [3-7], fewer GABA receptor subunits have been observed in the post-mortem tissue of autistic individuals [8, 9], and GABAergic signaling is disrupted across heterogeneous mouse models of autism [10]. Yet, empirical evidence supporting this hypothesis in humans is lacking, leaving a gulf between animal and human studies of the condition. Here, we present a direct link between GABA signaling and autistic perceptual symptomatology. We first demonstrate a robust, replicated autistic deficit in binocular rivalry [11], a basic visual function that is thought to rely on the balance of excitation/inhibition in visual cortex [12-15]. Then, using magnetic resonance spectroscopy, we demonstrate a tight linkage between binocular rivalry dynamics in typical participants and both GABA and glutamate levels in the visual cortex. Finally, we show that the link between GABA and binocular rivalry dynamics is completely and specifically absent in autism. These results suggest a disruption in inhibitory signaling in the autistic brain and forge a translational path between animal and human models of the condition.
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Affiliation(s)
- Caroline E Robertson
- Harvard Society of Fellows, Harvard University, Cambridge, MA 02138, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02138, USA.
| | - Eva-Maria Ratai
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nancy Kanwisher
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02138, USA
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187
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Cawley N, Solanky BS, Muhlert N, Tur C, Edden RAE, Wheeler-Kingshott CAM, Miller DH, Thompson AJ, Ciccarelli O. Reduced gamma-aminobutyric acid concentration is associated with physical disability in progressive multiple sclerosis. Brain 2015; 138:2584-95. [PMID: 26304151 DOI: 10.1093/brain/awv209] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neurodegeneration is thought to be the major cause of ongoing, irreversible disability in progressive stages of multiple sclerosis. Gamma-aminobutyric acid is the principle inhibitory neurotransmitter in the brain. The aims of this study were to investigate if gamma-aminobutyric acid levels (i) are abnormal in patients with secondary progressive multiple sclerosis compared with healthy controls; and (ii) correlate with physical and cognitive performance in this patient population. Thirty patients with secondary progressive multiple sclerosis and 17 healthy control subjects underwent single-voxel MEGA-PRESS (MEscher-GArwood Point RESolved Spectroscopy) magnetic resonance spectroscopy at 3 T, to quantify gamma-aminobutyric acid levels in the prefrontal cortex, right hippocampus and left sensorimotor cortex. All subjects were assessed clinically and underwent a cognitive assessment. Multiple linear regression models were used to compare differences in gamma-aminobutyric acid concentrations between patients and controls adjusting for age, gender and tissue fractions within each spectroscopic voxel. Regression was used to examine the relationships between the cognitive function and physical disability scores specific for these regions with gamma-aminobuytric acid levels, adjusting for age, gender, and total N-acetyl-aspartate and glutamine-glutamate complex levels. When compared with controls, patients performed significantly worse on all motor and sensory tests, and were cognitively impaired in processing speed and verbal memory. Patients had significantly lower gamma-aminobutyric acid levels in the hippocampus (adjusted difference = -0.403 mM, 95% confidence intervals -0.792, -0.014, P = 0.043) and sensorimotor cortex (adjusted difference = -0.385 mM, 95% confidence intervals -0.667, -0.104, P = 0.009) compared with controls. In patients, reduced motor function in the right upper and lower limb was associated with lower gamma-aminobutyric acid concentration in the sensorimotor cortex. Specifically for each unit decrease in gamma-aminobutyric acid levels (in mM), there was a predicted -10.86 (95% confidence intervals -16.786 to -4.482) decrease in grip strength (kg force) (P < 0.001) and -8.74 (95% confidence intervals -13.943 to -3.015) decrease in muscle strength (P < 0.006). This study suggests that reduced gamma-aminobutyric acid levels reflect pathological abnormalities that may play a role in determining physical disability. These abnormalities may include decreases in the pre- and postsynaptic components of gamma-aminobutyric acid neurotransmission and in the density of inhibitory neurons. Additionally, the reduced gamma-aminobutyric acid concentration may contribute to the neurodegenerative process, resulting in increased firing of axons, with consequent increased energy demands, which may lead to neuroaxonal degeneration and loss of the compensatory mechanisms that maintain motor function. This study supports the idea that modulation of gamma-aminobutyric acid neurotransmission may be an important target for neuroprotection in multiple sclerosis.See De Stefano and Giorgio (doi:10.1093/brain/awv213) for a scientific commentary on this article.
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Affiliation(s)
- Niamh Cawley
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK
| | - Bhavana S Solanky
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK
| | - Nils Muhlert
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK 2 School of Psychology and Cardiff University Brain Research Imaging Centre, Cardiff University, Cardiff, UK 3 School of Psychological Sciences, University of Manchester, Manchester, UK
| | - Carmen Tur
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK
| | - Richard A E Edden
- 4 Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA 5 FM Kirby Centre for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Claudia A M Wheeler-Kingshott
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK 6 Brain Connectivity Centre, C. Mondino National Neurological Institute, Pavia, Italy
| | - David H Miller
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK 7 National Institute of Health Research (NIHR) University College London Hospitals (UCLH) Biomedical Research Centre (BRC), London, UK
| | - Alan J Thompson
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK 7 National Institute of Health Research (NIHR) University College London Hospitals (UCLH) Biomedical Research Centre (BRC), London, UK
| | - Olga Ciccarelli
- 1 NMR Research Unit, Queen Square Multiple Sclerosis Centre, UCL Institute of Neurology, London, UK 7 National Institute of Health Research (NIHR) University College London Hospitals (UCLH) Biomedical Research Centre (BRC), London, UK
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188
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Janik R, Thomason LAM, Stanisz AM, Forsythe P, Bienenstock J, Stanisz GJ. Magnetic resonance spectroscopy reveals oral Lactobacillus promotion of increases in brain GABA, N-acetyl aspartate and glutamate. Neuroimage 2015; 125:988-995. [PMID: 26577887 DOI: 10.1016/j.neuroimage.2015.11.018] [Citation(s) in RCA: 182] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 10/25/2015] [Accepted: 11/08/2015] [Indexed: 01/09/2023] Open
Abstract
The gut microbiome has been shown to regulate the development and functions of the enteric and central nervous systems. Its involvement in the regulation of behavior has attracted particular attention because of its potential translational importance in clinical disorders, however little is known about the pathways involved. We previously have demonstrated that administration of Lactobacillus rhamnosus (JB-1) to healthy male BALB/c mice, promotes consistent changes in GABA-A and -B receptor sub-types in specific brain regions, accompanied by reductions in anxiety and depression-related behaviors. In the present study, using magnetic resonance spectroscopy (MRS), we quantitatively assessed two clinically validated biomarkers of brain activity and function, glutamate+glutamine (Glx) and total N-acetyl aspartate+N-acetyl aspartyl glutamic acid (tNAA), as well as GABA, the chief brain inhibitory neurotransmitter. Mice received 1×10(9) cfu of JB-1 per day for 4weeks and were subjected to MRS weekly and again 4weeks after cessation of treatment to ascertain temporal changes in these neurometabolites. Baseline concentrations for Glx, tNAA and GABA were equal to 10.4±0.3mM, 8.7±0.1mM, and 1.2±0.1mM, respectively. Delayed increases were first seen for Glx (~10%) and NAA (~37%) at 2weeks which persisted only to the end of treatment. However, Glx was still elevated 4weeks after treatment had ceased. Significantly elevated GABA (~25%) was only seen at 4weeks. These results suggest specific metabolic pathways in our pursuit of mechanisms of action of psychoactive bacteria. They also offer through application of standard clinical neurodiagnostic techniques, translational opportunities to assess biomarkers accompanying behavioral changes induced by alterations in the gut microbiome.
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Affiliation(s)
- Rafal Janik
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
| | - Lynsie A M Thomason
- Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada
| | - Andrew M Stanisz
- McMaster Brain-Body Institute at St. Joseph's Healthcare Hamilton, T3304, Juravinski Tower, 50 Charlton Avenue East, Hamilton, ON L8N 4A6, Canada
| | - Paul Forsythe
- Department of Medicine, McMaster University, St. Joseph's Healthcare Hamilton, T3302, 50 Charlton Avenue East, Hamilton, ON L8N 4A6, Canada; McMaster Brain-Body Institute at St. Joseph's Healthcare Hamilton, T3304, Juravinski Tower, 50 Charlton Avenue East, Hamilton, ON L8N 4A6, Canada
| | - John Bienenstock
- Department of Pathology, McMaster University, St. Joseph's Healthcare Hamilton,, Juravinski Tower, 50 Charlton Avenue East, Hamilton, ON L8N 4A6, Canada; McMaster Brain-Body Institute at St. Joseph's Healthcare Hamilton, T3304, Juravinski Tower, 50 Charlton Avenue East, Hamilton, ON L8N 4A6, Canada
| | - Greg J Stanisz
- Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Physical Sciences, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada; Department of Neurosurgery and Pediatrics Neurosurgery, Medical University of Lublin, Aleje Raclawickie 1, 20-059 Lublin, Poland.
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189
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Mocioiu V, Ortega-Martorell S, Olier I, Jablonski M, Starcukova J, Lisboa P, Arús C, Julià-Sapé M. From raw data to data-analysis for magnetic resonance spectroscopy--the missing link: jMRUI2XML. BMC Bioinformatics 2015; 16:378. [PMID: 26552737 PMCID: PMC4640235 DOI: 10.1186/s12859-015-0796-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/27/2015] [Indexed: 11/23/2022] Open
Abstract
Background Magnetic resonance spectroscopy provides metabolic information about living tissues in a non-invasive way. However, there are only few multi-centre clinical studies, mostly performed on a single scanner model or data format, as there is no flexible way of documenting and exchanging processed magnetic resonance spectroscopy data in digital format. This is because the DICOM standard for spectroscopy deals with unprocessed data. This paper proposes a plugin tool developed for jMRUI, namely jMRUI2XML, to tackle the latter limitation. jMRUI is a software tool for magnetic resonance spectroscopy data processing that is widely used in the magnetic resonance spectroscopy community and has evolved into a plugin platform allowing for implementation of novel features. Results jMRUI2XML is a Java solution that facilitates common preprocessing of magnetic resonance spectroscopy data across multiple scanners. Its main characteristics are: 1) it automates magnetic resonance spectroscopy preprocessing, and 2) it can be a platform for outputting exchangeable magnetic resonance spectroscopy data. The plugin works with any kind of data that can be opened by jMRUI and outputs in extensible markup language format. Data processing templates can be generated and saved for later use. The output format opens the way for easy data sharing- due to the documentation of the preprocessing parameters and the intrinsic anonymization - for example for performing pattern recognition analysis on multicentre/multi-manufacturer magnetic resonance spectroscopy data. Conclusions jMRUI2XML provides a self-contained and self-descriptive format accounting for the most relevant information needed for exchanging magnetic resonance spectroscopy data in digital form, as well as for automating its processing. This allows for tracking the procedures the data has undergone, which makes the proposed tool especially useful when performing pattern recognition analysis. Moreover, this work constitutes a first proposal for a minimum amount of information that should accompany any magnetic resonance processed spectrum, towards the goal of achieving better transferability of magnetic resonance spectroscopy studies. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0796-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Victor Mocioiu
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, UAB, Cerdanyola del Vallès, Barcelona, 08193, Spain. .,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina CIBER-BBN, Cerdanyola del Vallès, Barcelona, Spain. .,Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.
| | - Sandra Ortega-Martorell
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina CIBER-BBN, Cerdanyola del Vallès, Barcelona, Spain. .,School of Computing and Mathematical Sciences, Liverpool John Moores University, Liverpool, UK.
| | - Iván Olier
- Institute of Biotechnology, The University of Manchester, Manchester, UK.
| | - Michal Jablonski
- Institute of Scientific Instruments of the CAS, v. v. i, Brno, Czech Republic.
| | - Jana Starcukova
- Institute of Scientific Instruments of the CAS, v. v. i, Brno, Czech Republic.
| | - Paulo Lisboa
- School of Computing and Mathematical Sciences, Liverpool John Moores University, Liverpool, UK.
| | - Carles Arús
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, UAB, Cerdanyola del Vallès, Barcelona, 08193, Spain. .,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina CIBER-BBN, Cerdanyola del Vallès, Barcelona, Spain. .,Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.
| | - Margarida Julià-Sapé
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, UAB, Cerdanyola del Vallès, Barcelona, 08193, Spain. .,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina CIBER-BBN, Cerdanyola del Vallès, Barcelona, Spain. .,Institut de Biotecnologia i Biomedicina (IBB), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain.
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190
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Martel D, Tse Ve Koon K, Le Fur Y, Ratiney H. Localized 2D COSY sequences: Method and experimental evaluation for a whole metabolite quantification approach. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 260:98-108. [PMID: 26432399 DOI: 10.1016/j.jmr.2015.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Revised: 09/03/2015] [Accepted: 09/04/2015] [Indexed: 05/08/2023]
Abstract
Two-dimensional spectroscopy offers the possibility to unambiguously distinguish metabolites by spreading out the multiplet structure of J-coupled spin systems into a second dimension. Quantification methods that perform parametric fitting of the 2D MRS signal have recently been proposed for resolved PRESS (JPRESS) but not explicitly for Localized Correlation Spectroscopy (LCOSY). Here, through a whole metabolite quantification approach, correlation spectroscopy quantification performances are studied. The ability to quantify metabolite relaxation constant times is studied for three localized 2D MRS sequences (LCOSY, LCTCOSY and the JPRESS) in vitro on preclinical MR systems. The issues encountered during implementation and quantification strategies are discussed with the help of the Fisher matrix formalism. The described parameterized models enable the computation of the lower bound for error variance--generally known as the Cramér Rao bounds (CRBs), a standard of precision--on the parameters estimated from these 2D MRS signal fittings. LCOSY has a theoretical net signal loss of two per unit of acquisition time compared to JPRESS. A rapid analysis could point that the relative CRBs of LCOSY compared to JPRESS (expressed as a percentage of the concentration values) should be doubled but we show that this is not necessarily true. Finally, the LCOSY quantification procedure has been applied on data acquired in vivo on a mouse brain.
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Affiliation(s)
- Dimitri Martel
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, France
| | - K Tse Ve Koon
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, France
| | - Yann Le Fur
- Aix-Marseille Université, CRMBM, CNRS UMR, 7339 Marseille, France
| | - Hélène Ratiney
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, France.
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191
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MR Spectra of Normal Adult Testes and Variations with Age: Preliminary Observations. Eur Radiol 2015; 26:2261-7. [PMID: 26474986 DOI: 10.1007/s00330-015-4055-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/21/2015] [Accepted: 10/01/2015] [Indexed: 01/08/2023]
Abstract
OBJECTIVES The aim was to determine the proton MR (1H-MR) spectra of normal adult testes and variations with age. METHODS Forty-one MR spectra of normal testes, including 16 testes from men aged 20-39 years (group I) and 25 testes from men aged 40-69 years (group II), were analyzed. A single-voxel point-resolved spectroscopy sequence (PRESS), with TR/TE: 2000/25 ms was used. The volume of interest was placed to include the majority of normal testicular parenchyma. Association between normalized metabolite concentrations, defined as ratios of the calculated metabolite concentrations relative to creatine concentration, and age was assessed. RESULTS Quantified metabolites of the spectra were choline (Cho), creatine (Cr), myo-inositol (mI), scyllo-inositol, taurine, lactate, GLx compound, glucose, lipids, and macromolecules resonating at 0.9 ppm (LM09), around 20 ppm (LM20), and at 13 ppm (LM13). Most prominent peaks were Cho, Cr, mI, and lipids. A weak negative correlation between mI and age (P = 0.015) was observed. Higher normalized concentrations of Cho (P = 0.03), mI (P = 0.08), and LM13 (P = 0.05) were found in group I than in group II. CONCLUSIONS 1H-MR spectra of a normal adult testis showed several metabolite peaks. A decrease of levels of Cho, mI, and LM13 was observed with advancing age. KEY POINTS • Single-voxel PRESS MRS of a normal testis is feasible. • 1H-MR spectra of a normal testis showed several metabolite peaks. • Most prominent peaks were Cho, Cr, mI, and lipids. • A decrease of Cho, mI, and LM13 was seen with advancing age.
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192
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Mora-Peris B, Winston A, Garvey L, Else LJ, Shattock RJ, Herrera C. HIV-1 CNS in vitro infectivity models based on clinical CSF samples. J Antimicrob Chemother 2015; 71:235-43. [PMID: 26472771 DOI: 10.1093/jac/dkv326] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/08/2015] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The concentration of antiretrovirals in CSF is often utilized as a surrogate for CNS drug exposure. This measurement does not consider pharmacodynamic or combinative effects of ART. We have developed a novel endpoint measurement to assess antiretroviral activity of CSF from subjects on ART. METHODS CSF samples were obtained from patients receiving tenofovir/emtricitabine (245/200 mg once daily) with either rilpivirine (25 mg once daily) or lopinavir/ritonavir/maraviroc (400/100/150 mg twice daily) and HIV-uninfected controls. Antiviral activity of ART-containing CSF was assessed in cell cultures using PBMCs and neuro-derived glial (U87) and astrocyte (373) cell lines. Infectivity model half-maximal inhibitory concentration (IMIC50) values were calculated and expressed as -log2IMIC50. Results were correlated with CSF antiretroviral concentrations. RESULTS Compared with controls, CSF from both ART studies demonstrated in vitro antiretroviral activity in all models. CSF antiretroviral activity of patients on lopinavir/ritonavir/maraviroc was significantly greater than that of patients on rilpivirine [-log2IMIC50 (95% CI) 4.82 (4.74-4.89) versus 3.43 (3.33-3.54) in PBMCs, 3.06 (2.98-3.15) versus 2.56 (2.46-2.65) in U87 cells and 6.00 (6.11-5.88) versus 4.90 (5.09-4.72) in 373 cells, respectively]. Positive correlations were observed for individual CSF antiretroviral activity in different cellular models with CSF concentrations of rilpivirine (P = 0.040 in 373 cells) and lopinavir (P = 0.048 in 373 cells), but not maraviroc. CONCLUSIONS Antiviral activity of CSF from patients on ART was successfully calculated and was greater with a regimen containing four active drugs compared with three active drugs. The use of neuro-derived cell lines alongside PBMCs to assess the effect of ART on CSF may act as a useful future clinical research tool.
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Affiliation(s)
- Borja Mora-Peris
- Department of Infectious Diseases and Immunity, Faculty of Medicine, Imperial College, London, UK Department of HIV and Genitourinary Medicine, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK
| | - Alan Winston
- Department of Infectious Diseases and Immunity, Faculty of Medicine, Imperial College, London, UK Department of HIV and Genitourinary Medicine, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK
| | - Lucy Garvey
- Department of Infectious Diseases and Immunity, Faculty of Medicine, Imperial College, London, UK Department of HIV and Genitourinary Medicine, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, UK
| | - Laura J Else
- Department of Clinical and Molecular Pharmacology, University of Liverpool, Liverpool, UK
| | - Robin J Shattock
- Department of Infectious Diseases and Immunity, Faculty of Medicine, Imperial College, London, UK
| | - Carolina Herrera
- Department of Infectious Diseases and Immunity, Faculty of Medicine, Imperial College, London, UK
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193
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Apšvalka D, Gadie A, Clemence M, Mullins PG. Event-related dynamics of glutamate and BOLD effects measured using functional magnetic resonance spectroscopy (fMRS) at 3T in a repetition suppression paradigm. Neuroimage 2015; 118:292-300. [PMID: 26072254 DOI: 10.1016/j.neuroimage.2015.06.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/01/2015] [Accepted: 06/04/2015] [Indexed: 12/30/2022] Open
Abstract
Proton MR spectroscopy ((1)H-MRS) complements other brain research methods by providing measures of neurometabolites noninvasively in a localized brain area. Improvements in MR scanner technologies, and data acquisition and analysis methods should allow functional (1)H-MRS (fMRS) to measure neurometabolite concentration changes during task-induced brain activation. The aim of the current study was to further develop event-related fMRS at 3T to investigate glutamate dynamics in response to repetition suppression. A secondary aim was to investigate the relationship between blood-oxygen-level-dependent (BOLD) responses and glutamate dynamics in the same paradigm at the same time. A novel approach of interleaved water-suppressed (metabolite) and unsuppressed (water) fMRS was used to simultaneously detect the event-related dynamics of glutamate and BOLD signal to repetition suppression in the lateral occipital cortex of thirteen (N=13) volunteers. On average, (1)H-MRS-visible glutamate increased after novel visual stimuli presentations by 12% and decreased by 11-13% on repeated compared to novel presentations. The BOLD signal, as measured by water peak amplitude changes, showed significant difference between Task and Rest trials, and, on a GLM based analysis of the time series, demonstrated a significant difference between the novel and repeated trials, however appeared to be decoupled from the glutamate response as no correlation was found between the two. These results are the first demonstration that reductions in neuronal activity typical of repetition suppression effects are reflected by reduced glutamatergic and BOLD measures, that glutamate and BOLD responses may not be coupled as previously thought, and that these changes and relationships can be measured simultaneously using event-related fMRS at 3T.
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Affiliation(s)
- Dace Apšvalka
- Bangor Imaging Center, School of Psychology, Bangor University, Bangor, Gwynedd LL57 2AS, UK
| | - Andrew Gadie
- Bangor Imaging Center, School of Psychology, Bangor University, Bangor, Gwynedd LL57 2AS, UK
| | - Matthew Clemence
- Philips Healthcare, Philips Centre, Guildford Business Park, Guildford, Surrey GU2 8HX, UK
| | - Paul G Mullins
- Bangor Imaging Center, School of Psychology, Bangor University, Bangor, Gwynedd LL57 2AS, UK.
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194
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Fauvelle F, Boccard J, Cavarec F, Depaulis A, Deransart C. Assessing Susceptibility to Epilepsy in Three Rat Strains Using Brain Metabolic Profiling Based on HRMAS NMR Spectroscopy and Chemometrics. J Proteome Res 2015; 14:2177-89. [PMID: 25761974 DOI: 10.1021/pr501309b] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The possibility that a metabolomic approach can inform about the pathophysiology of a given form of epilepsy was addressed. Using chemometric analyses of HRMAS NMR data, we compared several brain structures in three rat strains with different susceptibilities to absence epilepsy: Genetic Absence Epilepsy Rats from Strasbourg (GAERS), Non Epileptic Control rats (NEC), and Wistar rats. Two ages were investigated: 14 days postnatal (P14) before the onset of seizures and 5 month old adults with fully developed seizures (Adults). The relative concentrations of 19 metabolites were assessed using (1)H HRMAS NMR experiments. Univariate and multivariate analyses including multiblock models were used to identify the most discriminant metabolites. A strain-dependent evolution of glutamate, glutamine, scyllo-inositol, alanine, and glutathione was highlighted during cerebral maturation. In Adults, data from somatosensory and motor cortices allowed discrimination between GAERS and NEC rats with higher levels of scyllo-inositol, taurine, and phosphoethanolamine in NEC. This epileptic metabolic phenotype was in accordance with current pathophysiological hypothesis of absence epilepsy (i.e., seizure-generating and control networks) and putative resistance of NEC rats and was observed before seizure onset. This methodology could be very efficient in a clinical context.
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Affiliation(s)
- Florence Fauvelle
- †IRBA, 91223 Bretigny sur Orgne, France.,‡Univ. Grenoble Alpes, IRMaGe MRI facility, F-38000 Grenoble, France.,ΨCNRS, UIMS 3552, F-38000 Grenoble, France.,¶INSERM, US17, F-38000 Grenoble, France.,§INSERM U836, F-38042 Grenoble, France
| | - Julien Boccard
- #School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, CH-1211 Geneva, Switzerland
| | - Fanny Cavarec
- §INSERM U836, F-38042 Grenoble, France.,∥Univ. Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France
| | - Antoine Depaulis
- §INSERM U836, F-38042 Grenoble, France.,∥Univ. Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,⊥Centre Hospitalier Universitaire, F-38000 Grenoble, France
| | - Colin Deransart
- §INSERM U836, F-38042 Grenoble, France.,∥Univ. Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, F-38000 Grenoble, France.,⊥Centre Hospitalier Universitaire, F-38000 Grenoble, France
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195
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Durst CR, Michael N, Tustison NJ, Patrie JT, Raghavan P, Wintermark M, Sendhil Velan S. Noninvasive evaluation of the regional variations of GABA using magnetic resonance spectroscopy at 3 Tesla. Magn Reson Imaging 2015; 33:611-7. [PMID: 25708260 DOI: 10.1016/j.mri.2015.02.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 08/29/2014] [Accepted: 02/16/2015] [Indexed: 02/04/2023]
Abstract
PURPOSE Rapid regional fluctuations in GABA may result in inhomogeneous concentrations throughout the brain parenchyma. The goal of this study is to provide further insight into the natural distribution of GABA throughout the brain and thus determine if a surrogate site may be used for spectroscopy when evaluating motor diseases, neurological disorders, or psychiatric dysfunction. MATERIALS AND METHODS In this prospective study, eight healthy volunteers underwent spectroscopic evaluation of the frontal lobe, occipital lobe, lateral temporal lobe, basal ganglia, and both hippocampi using a spin echo variant of a J-difference editing method. Knowledge of the relative peak intensities of the macromolecule peaks at 3ppm and 0.9ppm was used to correct the contribution of co-edited macromolecules to the GABA peak at 3ppm. The GABA values were internally referenced to NAA. Linear regression was used to normalize the effect of regional tissue-fraction variation on the GABA/NAA values. A one-way ANOVA was performed with Tukey's multiple comparison test to compare the normalized GABA/NAA values in each pair of locations. RESULTS After accounting for the macromolecule contribution to the GABA signal and correction for tissue fraction variation, the normalized GABA/NAA ratios differ significantly between the six brain locations (p<0.001). Pairwise comparisons of the corrected normalized GABA/NAA ratios show statistically significant variation between the frontal lobe and the basal ganglia, frontal and lateral temporal lobes, and frontal lobe and right hippocampus. Variations in the normalized GABA/NAA ratios trend toward significance between the frontal lobe and left hippocampus, occipital lobe and the frontal lobe, occipital lobe and basal ganglia, and occipital lobe and right hippocampus. CONCLUSION Our study suggests that GABA concentration is inhomogeneous throughout the parenchyma. Studies evaluating the role of GABA must carefully consider voxel placement when incorporating spectroscopy.
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Affiliation(s)
- Christopher R Durst
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA.
| | - Navin Michael
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore
| | - Nicholas J Tustison
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - James T Patrie
- Department of Public Health Sciences, University of Virginia, Charlottesville, VA, USA
| | - Prashant Raghavan
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland, Baltimore, MD, USA
| | - Max Wintermark
- Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - S Sendhil Velan
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore; Laboratory of Molecular Imaging, Singapore Bioimaging Consortium, Agency for Science, Technology and Research, Singapore, Singapore; Clinical Imaging Research Centre, Agency for Science, Technology and Research, Singapore, NUS-A*STAR, Singapore
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196
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Striatum and entorhinal cortex atrophy in AD mouse models: MRI comprehensive analysis. Neurobiol Aging 2014; 36:776-88. [PMID: 25433456 DOI: 10.1016/j.neurobiolaging.2014.10.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 09/19/2014] [Accepted: 10/07/2014] [Indexed: 01/24/2023]
Abstract
Alzheimer's disease is experimentally modeled in transgenic (Tg) mice overexpressing mutated forms of the human amyloid precursor protein either alone or combined with mutated presenilins and tau. In the present study, we developed a systematic approach to compare double (TASTPM) and triple (APP/PS2/Tau) Tg mice by serial magnetic resonance imaging and spectroscopy analysis from 4 to 26 months of age to define homologous biomarkers between mice and humans. Hippocampal atrophy was found in Tg mice compared with WT. In APP/PS2/Tau the effect was age-dependent, whereas in TASTPM it was detectable from the first investigated time point. Importantly, both mice displayed an age-related entorhinal cortex thinning and robust striatal atrophy, the latter associated with a significant loss of synaptophysin. Hippocampal magnetic resonance spectroscopy revealed lower glutamate levels in both Tg mice and a selective myo-inositol increase in TASTPM. This noninvasive magnetic resonance imaging analysis, revealed common biomarkers between humans and mice, and could, thus, be promoted as a fully translational tool to be adopted in the preclinical investigation of therapeutic approaches.
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197
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Riese F, Gietl A, Zölch N, Henning A, O'Gorman R, Kälin AM, Leh SE, Buck A, Warnock G, Edden RAE, Luechinger R, Hock C, Kollias S, Michels L. Posterior cingulate γ-aminobutyric acid and glutamate/glutamine are reduced in amnestic mild cognitive impairment and are unrelated to amyloid deposition and apolipoprotein E genotype. Neurobiol Aging 2014; 36:53-9. [PMID: 25169676 DOI: 10.1016/j.neurobiolaging.2014.07.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/18/2014] [Accepted: 07/23/2014] [Indexed: 02/08/2023]
Abstract
The biomarker potential of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) for the in vivo characterization of preclinical stages in Alzheimer's disease has not yet been explored. We measured GABA, glutamate + glutamine (Glx), and N-acetyl-aspartate (NAA) levels by single-voxel MEGA-PRESS magnetic resonance spectroscopy in the posterior cingulate cortex of 21 elderly subjects and 15 patients with amnestic mild cognitive impairment. Participants underwent Pittsburgh Compound B positron emission tomography, apolipoprotein E (APOE) genotyping, and neuropsychological examination. GABA, Glx, and NAA levels were significantly lower in patients. NAA was lower in Pittsburgh Compound B-positive subjects and APOE ε4 allele carriers. GABA, Glx, and NAA levels were positively correlated to CERAD word learning scores. Reductions in GABA, Glx, and NAA levels may serve as metabolic biomarkers for cognitive impairment in amnestic mild cognitive impairment. Because GABA and Glx do not seem to reflect amyloid β deposition or APOE genotype, they are less likely biomarker candidates for preclinical Alzheimer's disease.
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Affiliation(s)
- Florian Riese
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Anton Gietl
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Niklaus Zölch
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Anke Henning
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; Max-Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Ruth O'Gorman
- Center of MR-Research, University Children's Hospital Zurich, Zurich, Switzerland
| | - Andrea M Kälin
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Sandra E Leh
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Alfred Buck
- Institute of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Geoffrey Warnock
- Institute of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Center for Functional Brain Imaging, Kenneddy Krieger Institute, Baltimore, MD, USA
| | - Roger Luechinger
- Institute of Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Christoph Hock
- Division of Psychiatry Research and Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Clinic of Neuroradiology, University Hospital Zurich, Zurich, Switzerland
| | - Lars Michels
- Clinic of Neuroradiology, University Hospital Zurich, Zurich, Switzerland.
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198
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Birch R, Peet AC, Arvanitis TN, Wilson M. Sensitivity encoding for fast (1) H MR spectroscopic imaging water reference acquisition. Magn Reson Med 2014; 73:2081-6. [PMID: 25046769 DOI: 10.1002/mrm.25355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 06/10/2014] [Accepted: 06/14/2014] [Indexed: 12/25/2022]
Abstract
PURPOSE Accurate and fast (1) H MR spectroscopic imaging (MRSI) water reference scans are important for absolute quantification of metabolites. However, the additional acquisition time required often precludes the water reference quantitation method for MRSI studies. Sensitivity encoding (SENSE) is a successful MR technique developed to reduce scan time. This study quantitatively assesses the accuracy of SENSE for water reference MRSI data acquisition, compared with the more commonly used reduced resolution technique. METHODS 2D MRSI water reference data were collected from a phantom and three volunteers at 3 Tesla for full acquisition (306 s); 2× reduced resolution (64 s) and SENSE R = 3 (56 s) scans. Water amplitudes were extracted using MRS quantitation software (TARQUIN). Intensity maps and Bland-Altman statistics were generated to assess the accuracy of the fast-MRSI techniques. RESULTS The average mean and standard deviation of differences from the full acquisition were 2.1 ± 3.2% for SENSE and 10.3 ± 10.7% for the reduced resolution technique, demonstrating that SENSE acquisition is approximately three times more accurate than the reduced resolution technique. CONCLUSION SENSE was shown to accurately reconstruct water reference data for the purposes of in vivo absolute metabolite quantification, offering significant improvement over the more commonly used reduced resolution technique.
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Affiliation(s)
- Rebecca Birch
- PSIBS Doctoral Training Centre, University of Birmingham, United Kingdom.,Department of Oncology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom
| | - Andrew C Peet
- Department of Oncology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom.,School of Cancer Sciences, University of Birmingham, United Kingdom
| | - Theodoros N Arvanitis
- Department of Oncology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom.,Institute of Digital Healthcare, WMG, University of Warwick, Coventry, United Kingdom
| | - Martin Wilson
- Department of Oncology, Birmingham Children's Hospital NHS Foundation Trust, Birmingham, United Kingdom.,School of Cancer Sciences, University of Birmingham, United Kingdom
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199
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Wilson M, Gill SK, MacPherson L, English M, Arvanitis TN, Peet AC. Noninvasive detection of glutamate predicts survival in pediatric medulloblastoma. Clin Cancer Res 2014; 20:4532-9. [PMID: 24947932 DOI: 10.1158/1078-0432.ccr-13-2320] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE Medulloblastoma is the most common malignant brain tumor occurring in childhood and is a significant cause of morbidity and mortality in pediatric oncology. More intense treatment strategies are recommended for patients displaying high-risk factors; however, considerable variation in outcome remains, indicating a need for improved predictive markers. In this study, 1H magnetic resonance spectroscopy (MRS) was used to investigate noninvasive molecular biomarkers of survival in medulloblastoma. EXPERIMENTAL DESIGN MRS was performed on a series of 35 biopsy-confirmed medulloblastoma cases. One case was excluded because of poor quality MRS. The prognostic value of MRS detectable biomarkers was investigated using Cox regression, retrospectively (N=15). A subsequent validation analysis (N=19) was also performed to reduce the chance of type I errors. Where available, high-resolution ex vivo MRS of biopsy tissue was used to confirm biomarker assignments. RESULTS The retrospective analysis revealed that creatine, glutamate, and glycine were markers of survival (P<0.01). The validation analysis showed that glutamate was a robust marker, with a hazard ration (HR) of 8.0 for the full dataset (P=0.0003, N=34). A good correlation between in vivo and ex vivo MRS glutamate/total-choline was found (P=0.001), validating the in vivo assignment. Ex vivo glutamate/total-choline was also associated with survival (P<0.01). CONCLUSION The identification of glutamate as a predictive biomarker of survival in pediatric medulloblastoma provides a clinically viable risk factor and highlights the importance of more detailed studies into the metabolism of this disease. Noninvasive biomarker detection using MRS may offer improved disease monitoring and potential for widespread use following multicenter validation.
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Affiliation(s)
- Martin Wilson
- School of Cancer Sciences, University of Birmingham, Birmingham; Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and
| | - Simrandip K Gill
- School of Cancer Sciences, University of Birmingham, Birmingham; Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and
| | - Lesley MacPherson
- Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and
| | - Martin English
- Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and
| | - Theodoros N Arvanitis
- Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and Institute of Digital Healthcare, WMG, University of Warwick, Coventry, United Kingdom
| | - Andrew C Peet
- School of Cancer Sciences, University of Birmingham, Birmingham; Birmingham Children's Hospital NHS Foundation Trust, Birmingham; and
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Skiöld B, Wu Q, Hooper SB, Davis PG, McIntyre R, Tolcos M, Pearson J, Vreys R, Egan GF, Barton SK, Cheong JLY, Polglase GR. Early detection of ventilation-induced brain injury using magnetic resonance spectroscopy and diffusion tensor imaging: an in vivo study in preterm lambs. PLoS One 2014; 9:e95804. [PMID: 24759765 PMCID: PMC3997476 DOI: 10.1371/journal.pone.0095804] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 03/31/2014] [Indexed: 11/18/2022] Open
Abstract
Background and Aim High tidal volume (VT) ventilation during resuscitation of preterm lambs results in brain injury evident histologically within hours after birth. We aimed to investigate whether magnetic resonance spectroscopy (MRS) and/or diffusion tensor imaging (DTI) can be used for early in vivo detection of ventilation-induced brain injury in preterm lambs. Methods Newborn lambs (0.85 gestation) were stabilized with a “protective ventilation” strategy (PROT, n = 7: prophylactic Curosurf, sustained inflation, VT 7 mL/kg, positive end expiratory pressure (PEEP) 5 cmH2O) or an initial 15 minutes of “injurious ventilation” (INJ, n = 10: VT 12 mL/kg, no PEEP, late Curosurf) followed by PROT ventilation for the remainder of the experiment. At 1 hour, lambs underwent structural magnetic resonance imaging (Siemens, 3 Tesla). For measures of mean/axial/radial diffusivity (MD, AD, RD) and fractional anisotropy (FA), 30 direction DTI was performed. Regions of interests encompassed the thalamus, internal capsule, periventricular white matter and the cerebellar vermis. MRS was performed using a localized single-voxel (15×15×20 mm3, echo time 270 ms) encompassing suptratentorial deep nuclear grey matter and central white matter. Peak-area ratios for lactate (Lac) relative to N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were calculated. Groups were compared using 2-way RM-ANOVA, Mann-Whitney U-test and Spearman's correlations. Results No cerebral injury was seen on structural MR images. Lambs in the INJ group had higher mean FA and lower mean RD in the thalamus compared to PROT lambs, but not in the other regions of interest. Peak-area lactate ratios >1.0 was only seen in INJ lambs. A trend of higher mean peak-area ratios for Lac/Cr and Lac/Cho was seen, which correlated with lower pH in both groups. Conclusion Acute changes in brain diffusion measures and metabolite peak-area ratios were observed after injurious ventilation. Early MRS/DTI is able to detect the initiation of ventilation-induced brain injury.
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Affiliation(s)
- Béatrice Skiöld
- Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia
- * E-mail:
| | - Qizhu Wu
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
- CSIRO Materials Science and Engineering, Clayton, Victoria, Australia
| | - Stuart B. Hooper
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
| | - Peter G. Davis
- Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia
| | - Richard McIntyre
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Mary Tolcos
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - James Pearson
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Ruth Vreys
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Gary F. Egan
- Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Samantha K. Barton
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
| | - Jeanie L. Y. Cheong
- Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia
- Victorian Infant Brain Studies, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Melbourne, Victoria, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Monash Institute of Medical Research, Monash University, Clayton, Victoria, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
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