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Armbruster R, Wilson N, Elliott MA, Liu F, Benyard B, Jacobs P, Swain A, Nanga RPR, Reddy R. Repeatability of Lac+ measurements in healthy human brain at 3 T. NMR IN BIOMEDICINE 2024:e5158. [PMID: 38584133 DOI: 10.1002/nbm.5158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 03/04/2024] [Accepted: 03/11/2024] [Indexed: 04/09/2024]
Abstract
PURPOSE In vivo quantification of lactate has numerous applications in studying the pathology of both cerebral and musculoskeletal systems. Due to its low concentration (~0.5-1 mM), and overlap with lipid signals, traditional 1H MR spectra acquired in vivo using a small voxel and short echo time often result in an inadequate signal to detect and resolve the lactate peak, especially in healthy human volunteers. METHODS In this study, using a semi-LASER acquisition with long echo time (TE = 288 ms) and large voxel size (80 × 70 × 20 mm3), we clearly visualize the combined signal of lactate and threonine. Therefore, we call the signal at 1.33 ppm Lac+ and quantify Lac+ concentration from water suppressed spectra in healthy human brains in vivo. Four participants (22-37 years old; mean age = 28 ± 5.4; three male, one female) were scanned on four separate days, and on each day four measurements were taken. Intra-day values are calculated for each participant by comparing the four measurements on a single day. Inter-day values were calculated using the mean intra-day measurements. RESULTS The mean intra-participant Lac+ concentration, standard deviation (SD), and coefficient of variation (CV) ranged from 0.49 to 0.61 mM, 0.02 to 0.07 mM, and 4% to 13%, respectively, across four volunteers. The inter-participant Lac+ concentration, SD, and CV was 0.53 mM, ±0.06 mM, and 11%. CONCLUSION Repeatability is shown in Lac+ measurement in healthy human brain using a long echo time semi-LASER sequence with a large voxel in about 3.5 min at 3 T.
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Affiliation(s)
- Ryan Armbruster
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Neil Wilson
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mark A Elliott
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Fang Liu
- Department of Biostatistics, Epidemiology, and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Blake Benyard
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul Jacobs
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anshuman Swain
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ravi Prakash Reddy Nanga
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ravinder Reddy
- Center for Advanced Metabolic Imaging in Precision Medicine, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Moore JE, Robison RK, Hu J, Sengupta ST, Mahdi OS, Anderson AW, Luo LY, Mohler AC, Merrell RT, Choi C. Optimization of the flip angles of narrow-band editing pulses in J-difference edited MRS of lactate at 3T. Magn Reson Med 2024; 91:886-895. [PMID: 38010083 PMCID: PMC10929535 DOI: 10.1002/mrm.29933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE Application of highly selective editing RF pulses provides a means of minimizing co-editing of contaminants in J-difference MRS (MEGA), but it causes reduction in editing yield. We examined the flip angles (FAs) of narrow-band editing pulses to maximize the lactate edited signal with minimal co-editing of threonine. METHODS The effect of editing-pulse FA on the editing performance was examined, with numerical and phantom analyses, for bandwidths of 17.6-300 Hz in MEGA-PRESS editing of lactate at 3T. The FA and envelope of 46 ms Gaussian editing pulses were tailored to maximize the lactate edited signal at 1.3 ppm and minimize co-editing of threonine. The optimized editing-pulse FA MEGA scheme was tested in brain tumor patients. RESULTS Simulation and phantom data indicated that the optimum FA of MEGA editing pulses is progressively larger than 180° as the editing-pulse bandwidth decreases. For 46 ms long 17.6 Hz bandwidth Gaussian pulses and other given sequence parameters, the lactate edited signal was maximum at the first and second editing-pulse FAs of 241° and 249°, respectively. The edit-on and difference-edited lactate peak areas of the optimized FA MEGA were greater by 43% and 25% compared to the 180°-FA MEGA, respectively. In-vivo data confirmed the simulation and phantom results. The lesions of the brain tumor patients showed elevated lactate and physiological levels of threonine. CONCLUSION The lactate MEGA editing yield is significantly increased with editing-pulse FA much larger than 180° when the editing-pulse bandwidth is comparable to the lactate quartet frequency width.
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Affiliation(s)
- Jason E. Moore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ryan K. Robison
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Philips, Nashville, TN, USA
| | - Jie Hu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Saikat T. Sengupta
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Olaimatu S. Mahdi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Adam W. Anderson
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Leo Y. Luo
- Department of Radiation Oncology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alexander C. Mohler
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ryan T. Merrell
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Changho Choi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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Robison RK, Haynes JR, Ganji SK, Nockowski CP, Kovacs Z, Pham W, Morgan VL, Smith SA, Thompson RC, Omary RA, Gore JC, Choi C. J-Difference editing (MEGA) of lactate in the human brain at 3T. Magn Reson Med 2023; 90:852-862. [PMID: 37154389 PMCID: PMC10901256 DOI: 10.1002/mrm.29693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/10/2023]
Abstract
PURPOSE The need to detect and quantify brain lactate accurately by MRS has stimulated the development of editing sequences based on J coupling effects. In J-difference editing of lactate, threonine can be co-edited and it contaminates lactate estimates due to the spectral proximity of the coupling partners of their methyl protons. We therefore implemented narrow-band editing 180° pulses (E180) in MEGA-PRESS acquisitions to resolve separately the 1.3-ppm resonances of lactate and threonine. METHODS Two 45.3-ms rectangular E180 pulses, which had negligible effects 0.15-ppm away from the carrier frequency, were implemented in a MEGA-PRESS sequence with TE 139 ms. Three acquisitions were designed to selectively edit lactate and threonine, in which the E180 pulses were tuned to 4.1 ppm, 4.25 ppm, and a frequency far off resonance. Editing performance was validated with numerical analyses and acquisitions from phantoms. The narrow-band E180 MEGA and another MEGA-PRESS sequence with broad-band E180 pulses were evaluated in six healthy subjects. RESULTS The 45.3-ms E180 MEGA offered a difference-edited lactate signal with lower intensity and reduced contamination from threonine compared to the broad-band E180 MEGA. The 45.3 ms E180 pulse had MEGA editing effects over a frequency range larger than seen in the singlet-resonance inversion profile. Lactate and threonine in healthy brain were both estimated to be 0.4 ± 0.1 mM, with reference to N-acetylaspartate at 12 mM. CONCLUSION Narrow-band E180 MEGA editing minimizes threonine contamination of lactate spectra and may improve the ability to detect modest changes in lactate levels.
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Affiliation(s)
- Ryan K Robison
- Philips, Nashville, Tennessee, USA
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Justin R Haynes
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Sandeep K Ganji
- Philips, Rochester, Minnesota, USA
- Mayo Clinic, Rochester, Minnesota, USA
| | - Charles P Nockowski
- Philips, Nashville, Tennessee, USA
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Wellington Pham
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Victoria L Morgan
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Seth A Smith
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
| | - Reid C Thompson
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Reed A Omary
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA
| | - Changho Choi
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Ganji SK, An Z, Tiwari V, Chang Y, Patel TR, Maher EA, Choi C. Optimization of spectrally selective 180° radiofrequency pulse timings in J-difference editing (MEGA) of lactate. Magn Reson Med 2022; 87:1150-1164. [PMID: 34657302 PMCID: PMC8776585 DOI: 10.1002/mrm.29051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/24/2021] [Accepted: 09/29/2021] [Indexed: 11/08/2022]
Abstract
PURPOSE J-Difference editing (MEGA) provides an effective spectroscopic means of selectively measuring low-concentration metabolites having weakly coupled spins. The fractional inphase and antiphase coherences are determined by the radiofrequency (RF) pulses and inter-RF pulse intervals of the sequence. We examined the timings of the spectrally selective editing 180° pulses (E180) in MEGA-PRESS to maximize the edited signal amplitude in lactate at 3T. METHODS The time evolution of the lactate spin coherences was analytically and numerically calculated for non-volume localized and single-voxel localized MEGA sequences. Single-voxel localized MEGA-PRESS simulations and phantom experiments were conducted for echo time (TE) 60-160 ms and for all possible integer-millisecond timings of the E180 pulses. Optimized E180 timings of 144, 103, and 109 ms TEs, tailored with simulation and phantom data, were tested in brain tumor patients in vivo. Lactate signals, broadened to singlet linewidths (~6 Hz), were compared between simulation, phantom, and in vivo data. RESULTS Theoretical and experimental data indicated consistently that the MEGA-edited signal amplitude and width are sensitive to the E180 timings. In volume-localized MEGA, the lactate peak amplitudes in E180-on and difference spectra were maximized at specific E180 timings for individual TEs, largely due to the chemical-shift displacement effects. The E180 timings for maximum lactate peak amplitude were different from those of maximum inphase coherence in in vivo linewidth situations. CONCLUSION In in vivo MEGA editing, the E180 pulse timings can be effectively used for manipulating the inphase and antiphase coherences and increasing the edited signal amplitude, following TE optimization.
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Affiliation(s)
- Sandeep K. Ganji
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas,Philips Healthcare, Andover, Massachusetts, USA
| | - Zhongxu An
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Vivek Tiwari
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Yongmin Chang
- Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | - Toral R. Patel
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elizabeth A. Maher
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Annette G. Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas,Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Choi IY, Andronesi OC, Barker P, Bogner W, Edden RAE, Kaiser LG, Lee P, Marjańska M, Terpstra M, de Graaf RA. Spectral editing in 1 H magnetic resonance spectroscopy: Experts' consensus recommendations. NMR IN BIOMEDICINE 2021; 34:e4411. [PMID: 32946145 PMCID: PMC8557623 DOI: 10.1002/nbm.4411] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 05/08/2023]
Abstract
Spectral editing in in vivo 1 H-MRS provides an effective means to measure low-concentration metabolite signals that cannot be reliably measured by conventional MRS techniques due to signal overlap, for example, γ-aminobutyric acid, glutathione and D-2-hydroxyglutarate. Spectral editing strategies utilize known J-coupling relationships within the metabolite of interest to discriminate their resonances from overlying signals. This consensus recommendation paper provides a brief overview of commonly used homonuclear editing techniques and considerations for data acquisition, processing and quantification. Also, we have listed the experts' recommendations for minimum requirements to achieve adequate spectral editing and reliable quantification. These include selecting the right editing sequence, dealing with frequency drift, handling unwanted coedited resonances, spectral fitting of edited spectra, setting up multicenter clinical trials and recommending sequence parameters to be reported in publications.
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Affiliation(s)
- In-Young Choi
- Department of Neurology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, Kansas
| | - Ovidiu C Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Peter Barker
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, F. M. Kirby Center for Functional MRI, Kennedy Krieger Institute, Baltimore, Maryland
| | - Wolfgang Bogner
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Richard A E Edden
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, F. M. Kirby Center for Functional MRI, Kennedy Krieger Institute, Baltimore, Maryland
| | - Lana G Kaiser
- Henry H. Wheeler, Jr. Brain Imaging Center, University of California, Berkeley, California
| | - Phil Lee
- Department of Radiology, Hoglund Biomedical Imaging Center, University of Kansas Medical Center, Kansas City, Kansas
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota
| | - Melissa Terpstra
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, Minnesota
| | - Robin A de Graaf
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut
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6
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Dacko M, Lange T. Flexible MEGA editing scheme with asymmetric adiabatic pulses applied for T 2 measurement of lactate in human brain. Magn Reson Med 2020; 85:1160-1174. [PMID: 32975334 DOI: 10.1002/mrm.28500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 11/09/2022]
Abstract
PURPOSE A flexible MEGA editing scheme which decouples the editing efficiency from TE is proposed and the utility of asymmetric adiabatic pulses for this new technique is explored. It is demonstrated that the method enables robust T 2 measurement of lactate in healthy human brain. METHODS The proposed variation of the MEGA scheme applies editing pulses in both acquired spectra, ensuring that the difference in J-evolution of the target resonance leads to maximal signal yield in the difference spectrum for arbitrary TE. A MEGA-sLASER sequence is augmented with asymmetric adiabatic editing pulses for enhanced flexibility and immunity to B 1 + miscalibration and inhomogeneities. The technique is validated and optimized for flexible lactate editing via a simple analytical model, numerical simulations and in vitro experiments. The T 2 relaxation constant of lactate is determined in vivo via multiple-TE measurements with the proposed method and a dedicated postprocessing and quantification approach. RESULTS Asymmetric adiabatic editing pulses improve robustness and facilitate efficient J-editing in sequences or protocols with strong timing constraints. Single voxel measurements using the proposed MEGA scheme in the occipital cortex of six healthy subjects yield a relaxation constant of T 2 = 171 ± 19 ms for the methyl resonance of lactate at a field strength of 3T. CONCLUSIONS The proposed MEGA editing scheme allows for novel kinds of J-editing experiments and promises to be an asset to robust T 2 measurement of lactate and potentially other J-coupled metabolites in vivo.
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Affiliation(s)
- Michael Dacko
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Lange
- Center for Diagnostic and Therapeutic Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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7
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Pang R, Martinello KA, Meehan C, Avdic-Belltheus A, Lingam I, Sokolska M, Mutshiya T, Bainbridge A, Golay X, Robertson NJ. Proton Magnetic Resonance Spectroscopy Lactate/N-Acetylaspartate Within 48 h Predicts Cell Death Following Varied Neuroprotective Interventions in a Piglet Model of Hypoxia-Ischemia With and Without Inflammation-Sensitization. Front Neurol 2020; 11:883. [PMID: 33013626 PMCID: PMC7500093 DOI: 10.3389/fneur.2020.00883] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 07/10/2020] [Indexed: 12/24/2022] Open
Abstract
Despite therapeutic hypothermia, survivors of neonatal encephalopathy have high rates of adverse outcome. Early surrogate outcome measures are needed to speed up the translation of neuroprotection trials. Thalamic lactate (Lac)/N-acetylaspartate (NAA) peak area ratio acquired with proton (1H) magnetic resonance spectroscopy (MRS) accurately predicts 2-year neurodevelopmental outcome. We assessed the relationship between MR biomarkers acquired at 24-48 h following injury with cell death and neuroinflammation in a piglet model following various neuroprotective interventions. Sixty-seven piglets with hypoxia-ischemia, hypoxia alone, or lipopolysaccharide (LPS) sensitization were included, and neuroprotective interventions were therapeutic hypothermia, melatonin, and magnesium. MRS and diffusion-weighted imaging (DWI) were acquired at 24 and 48 h. At 48 h, experiments were terminated, and immunohistochemistry was assessed. There was a correlation between Lac/NAA and overall cell death [terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)] [mean Lac/NAA basal ganglia and thalamus (BGT) voxel r = 0.722, white matter (WM) voxel r = 0.784, p < 0.01] and microglial activation [ionized calcium-binding adapter molecule 1 (Iba1)] (BGT r = -0.786, WM r = -0.632, p < 0.01). Correlation with marker of caspase-dependent apoptosis [cleaved caspase 3 (CC3)] was lower (BGT r = -0.636, WM r = -0.495, p < 0.01). Relation between DWI and TUNEL was less robust (mean diffusivity BGT r = -0.615, fractional anisotropy BGT r = 0.523). Overall, Lac/NAA correlated best with cell death and microglial activation. These data align with clinical studies demonstrating Lac/NAA superiority as an outcome predictor in neonatal encephalopathy (NE) and support its use in preclinical and clinical neuroprotection studies.
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Affiliation(s)
- Raymand Pang
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Kathryn A. Martinello
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Christopher Meehan
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Adnan Avdic-Belltheus
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Ingran Lingam
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Magda Sokolska
- Medical Physics and Engineering, University College London NHS Foundation Trust, London, United Kingdom
| | - Tatenda Mutshiya
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Alan Bainbridge
- Medical Physics and Engineering, University College London NHS Foundation Trust, London, United Kingdom
| | - Xavier Golay
- Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom
| | - Nicola J. Robertson
- Department of Neonatology, Institute for Women's Health, University College London, London, United Kingdom
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Dacko M, Lange T. Improved detection of lactate and β-hydroxybutyrate using MEGA-sLASER at 3 T. NMR IN BIOMEDICINE 2019; 32:e4100. [PMID: 31038254 DOI: 10.1002/nbm.4100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 02/28/2019] [Accepted: 03/12/2019] [Indexed: 06/09/2023]
Abstract
Lactate and β-hydroxybutyrate are important MRS-visible biomarkers for the energy metabolism of the human brain. A major obstacle for their unambiguous detection and quantification in vivo is their inherently low concentration and spectral overlap with resonances from lipids and macromolecules. In this work, we demonstrate the improved detectability of lactate and β-hydroxybutyrate with MEGA-sLASER compared to MEGA-PRESS at the clinical field strength of 3 T. The method is validated by numerical simulations, in vitro measurements and in vivo experiments on healthy subjects. It is demonstrated that MEGA-sLASER offers an SNR increase of approximately 70% for lactate and β-hydroxybutyrate detection compared to MEGA-PRESS in various brain regions. This increased SNR translates into reduced Cramér-Rao lower bounds for quantification and enables a more robust detection of subtle changes in the (brain) energy metabolism. The sensitivity of the method for detection of β-hydroxybutyrate concentration changes is demonstrated through measurements before and during a ketogenic diet while the sensitivity for detection of lactate concentration changes is shown by measurements before and after an intensive anaerobic exercise.
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Affiliation(s)
- Michael Dacko
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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9
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Tiwari V, An Z, Ganji SK, Baxter J, Patel TR, Pan E, Mickey BE, Maher EA, Pinho MC, Choi C. Measurement of glycine in healthy and tumorous brain by triple-refocusing MRS at 3 T in vivo. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3747. [PMID: 28548710 PMCID: PMC5557683 DOI: 10.1002/nbm.3747] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 05/21/2023]
Abstract
Glycine (Gly) has been implicated in several neurological disorders, including malignant brain tumors. The precise measurement of Gly is challenging largely as a result of the spectral overlap with myo-inositol (mI). We report a new triple-refocusing sequence for the reliable co-detection of Gly and mI at 3 T and for the evaluation of Gly in healthy and tumorous brain. The sequence parameters were optimized with density-matrix simulations and phantom validation. With a total TE of 134 ms, the sequence gave complete suppression of the mI signal between 3.5 and 3.6 ppm and, consequently, well-defined Gly (3.55 ppm) and mI (3.64 ppm) peaks. In vivo 1 H magnetic resonance spectroscopy (MRS) data were acquired from the gray matter (GM)-dominant medial occipital and white matter (WM)-dominant left parietal regions in six healthy subjects, and analyzed with LCModel using in-house-calculated basis spectra. Tissue segmentation was performed to obtain the GM and WM contents within the MRS voxels. Metabolites were quantified with reference to GM-rich medial occipital total creatine at 8 mM. The Gly and mI concentrations were estimated to be 0.63 ± 0.05 and 8.6 ± 0.6 mM for the medial occipital and 0.34 ± 0.05 and 5.3 ± 0.8 mM for the left parietal regions, respectively. From linear regression of the metabolite estimates versus fractional GM content, the concentration ratios between pure GM and pure WM were estimated to be 2.6 and 2.1 for Gly and mI, respectively. Clinical application of the optimized sequence was performed in four subjects with brain tumor. The Gly levels in tumors were higher than those of healthy brain. Gly elevation was more extensive in a post-contrast enhancing region than in a non-enhancing region. The data indicate that the optimized triple-refocusing sequence may provide reliable co-detection of Gly and mI, and alterations of Gly in brain tumors can be precisely evaluated.
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Affiliation(s)
- Vivek Tiwari
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Zhongxu An
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sandeep K. Ganji
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jeannie Baxter
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Toral R. Patel
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Edward Pan
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Bruce E. Mickey
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Annette Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elizabeth A. Maher
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Annette Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Marco C. Pinho
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Correspondence to: Changho Choi, PhD, Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, Texas 75390-8542,
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10
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Magnetic Resonance Spectroscopy and its Clinical Applications: A Review. J Med Imaging Radiat Sci 2017; 48:233-253. [PMID: 31047406 DOI: 10.1016/j.jmir.2017.06.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/30/2017] [Accepted: 06/22/2017] [Indexed: 12/25/2022]
Abstract
In vivo NMR spectroscopy is known as magnetic resonance spectroscopy (MRS). MRS has been applied as both a research and a clinical tool in order to detect visible or nonvisible abnormalities. The adaptability of MRS allows a technique that can probe a wide variety of metabolic uses across different tissues. Although MRS is mostly applied for brain tissue, it can be used for detection, localization, staging, tumour aggressiveness evaluation, and tumour response assessment of breast, prostate, hepatic, and other cancers. In this article, the medical applications of MRS in the brain, including tumours, neural and psychiatric disorder studies, breast, prostate, hepatic, gastrointestinal, and genitourinary investigations have been reviewed.
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11
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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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12
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Payne GS, Harris LM, Cairns GS, Messiou C, deSouza NM, Macdonald A, Saran F, Leach MO. Validating a robust double-quantum-filtered (1) H MRS lactate measurement method in high-grade brain tumours. NMR IN BIOMEDICINE 2016; 29:1420-6. [PMID: 27514007 PMCID: PMC5042032 DOI: 10.1002/nbm.3587] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 06/23/2016] [Accepted: 06/23/2016] [Indexed: 05/23/2023]
Abstract
(1) H MRS measurements of lactate are often confounded by overlapping lipid signals. Double-quantum (DQ) filtering eliminates lipid signals and permits single-shot measurements, which avoid subtraction artefacts in moving tissues. This study evaluated a single-voxel-localized DQ filtering method qualitatively and quantitatively for measuring lactate concentrations in the presence of lipid, using high-grade brain tumours in which the results could be compared with standard acquisition as a reference. Paired standard acquisition and DQ-filtered (1) H MR spectra were acquired at 3T from patients receiving treatment for glioblastoma, using fLASER (localization by adiabatic selective refocusing using frequency offset corrected inversion pulses) single-voxel localization. Data were acquired from 2 × 2 × 2 cm(3) voxels, with a repetition time of 1 s and 128 averages (standard acquisition) or 256 averages (DQ-filtered acquisition), requiring 2.15 and 4.3 min respectively. Of 37 evaluated data pairs, 20 cases (54%) had measureable lactate (fitted Cramér-Rao lower bounds ≤ 20%) in either the DQ-filtered or the standard acquisition spectra. The measured DQ-filtered lactate signal was consistently downfield of lipid (1.33 ± 0.03 ppm vs 1.22 ± 0.08 ppm; p = 0.002), showing that it was not caused by lipid breakthrough, and that it matched the lactate signal seen in standard measurements (1.36 ± 0.02 ppm). In the absence of lipid, similar lactate concentrations were measured by the two methods (mean ratio DQ filtered/standard acquisition = 1.10 ± 0.21). In 7/20 cases with measurable lactate, signal was not measureable in the standard acquisition owing to lipid overlap but was quantified in the DQ-filtered acquisition. Conversely, lactate was undetected in seven DQ-filtered acquisitions but visible using the standard acquisition. In conclusion, the DQ filtering method has proven robust in eliminating lipid and permits uncontaminated measurement of lactate. This is important validation prior to use in tissues outside the brain, which contain large amounts of lipid and which are often susceptible to motion.
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Affiliation(s)
- G S Payne
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK.
| | - L M Harris
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - G S Cairns
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - C Messiou
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - N M deSouza
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - A Macdonald
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - F Saran
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
| | - M O Leach
- MRI Unit, Royal Marsden Hospital, Sutton, Surrey, UK
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13
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Holbach M, Lambert J, Johst S, Ladd ME, Suter D. Optimized selective lactate excitation with a refocused multiple-quantum filter. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 255:34-38. [PMID: 25909643 DOI: 10.1016/j.jmr.2015.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 02/20/2015] [Accepted: 03/09/2015] [Indexed: 06/04/2023]
Abstract
Selective detection of lactate signals in in vivo MR spectroscopy with spectral editing techniques is necessary in situations where strong lipid or signals from other molecules overlap the desired lactate resonance in the spectrum. Several pulse sequences have been proposed for this task. The double-quantum filter SSel-MQC provides very good lipid and water signal suppression in a single scan. As a major drawback, it suffers from significant signal loss due to incomplete refocussing in situations where long evolution periods are required. Here we present a refocused version of the SSel-MQC technique that uses only one additional refocussing pulse and regains the full refocused lactate signal at the end of the sequence.
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Affiliation(s)
- Mirjam Holbach
- Experimental Physics III, TU Dortmund University, 44227 Dortmund, Germany.
| | - Jörg Lambert
- Leibniz Institut für Analytische Wissenschaften - ISAS e.V., 44139 Dortmund, Germany
| | - Sören Johst
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, 45141 Essen, Germany
| | - Mark E Ladd
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, 45141 Essen, Germany; Medical Physics in Radiology, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Dieter Suter
- Experimental Physics III, TU Dortmund University, 44227 Dortmund, Germany
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14
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Madan A, Ganji SK, An Z, Choe KS, Pinho MC, Bachoo RM, Maher EM, Choi C. Proton T2 measurement and quantification of lactate in brain tumors by MRS at 3 Tesla in vivo. Magn Reson Med 2014; 73:2094-9. [PMID: 25046359 DOI: 10.1002/mrm.25352] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/11/2014] [Accepted: 06/14/2014] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate the T2 relaxation time of lactate (Lac) in brain tumors and the correlation of the T2 and concentration with tumor grades. METHODS Eight pairs of the subecho time sets of point-resolved spectroscopy were selected between 58 and 268 ms, with numerical and phantom analyses, for Lac T2 measurement. In vivo spectra were acquired from 24 subjects with gliomas (13 low grade and 11 high grade) and analyzed with LCModel using numerically-calculated basis spectra. The metabolite T2 relaxation time was obtained from monoexponential fitting of the multi-echo time (TE) signal estimates versus TE. The metabolite concentration was estimated from the zero-TE extrapolation of the T2 fits. RESULTS The Lac T2 was estimated to be approximately 240 ms, without a significant difference between low and high grade tumors. The Lac concentration was estimated to be 4.1 ± 3.4 and 7.0 ± 4.7 mM for low and high grades respectively, but the difference was not significant. CONCLUSION The Lac T2 was similar among gliomas regardless of their tumor grades. This suggests that the T2 value from this study may be applicable to obtain the T2 relaxation-free estimates of Lac in a subset of brain tumors.
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Affiliation(s)
- Akshay Madan
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sandeep K Ganji
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Zhongxu An
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kevin S Choe
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Marco C Pinho
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Robert M Bachoo
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Annette Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elizabeth M Maher
- Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Annette Strauss Center for Neuro-Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Harold C. Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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15
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Holbach M, Lambert J, Suter D. Optimized multiple-quantum filter for robust selective excitation of metabolite signals. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 243:8-16. [PMID: 24705532 DOI: 10.1016/j.jmr.2014.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/30/2014] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
The selective excitation of metabolite signals in vivo requires the use of specially adapted pulse techniques, in particular when the signals are weak and the resonances overlap with those of unwanted molecules. Several pulse sequences have been proposed for this spectral editing task. However, their performance is strongly degraded by unavoidable experimental imperfections. Here, we show that optimal control theory can be used to generate pulses and sequences that perform almost ideally over a range of rf field strengths and frequency offsets that can be chosen according to the specifics of the spectrometer or scanner being used. We demonstrate this scheme by applying it to lactate editing. In addition to the robust excitation, we also have designed the pulses to minimize the signal of unwanted molecular species.
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Affiliation(s)
- Mirjam Holbach
- Experimental Physics III, TU Dortmund University, 44227 Dortmund, Germany.
| | - Jörg Lambert
- Leibniz-Institut für Analytische Wissenschaften, ISAS e.V., 44139 Dortmund, Germany
| | - Dieter Suter
- Experimental Physics III, TU Dortmund University, 44227 Dortmund, Germany
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16
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Devience SJ, Walsworth RL, Rosen MS. Nuclear spin singlet states as a contrast mechanism for NMR spectroscopy. NMR IN BIOMEDICINE 2013; 26:1204-1212. [PMID: 23606451 DOI: 10.1002/nbm.2936] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 12/04/2012] [Accepted: 01/31/2013] [Indexed: 06/02/2023]
Abstract
Nuclear magnetic resonance (NMR) spectra of complex chemical mixtures often contain unresolved or hidden spectral components, especially when strong background signals overlap weaker peaks. In this article we demonstrate a quantum filter utilizing nuclear spin singlet states, which allows undesired NMR spectral background to be removed and target spectral peaks to be uncovered. The quantum filter is implemented by creating a nuclear spin singlet state with spin quantum numbers j = 0, mz = 0 in a target molecule, applying a continuous RF field to both preserve the singlet state and saturate the magnetization of undesired molecules and then mapping the target molecule singlet state back into an NMR observable state so that its spectrum can be read out unambiguously. The preparation of the target singlet state can be carefully controlled with pulse sequence parameters, so that spectral contrast can be achieved between molecules with very similar structures. We name this NMR contrast mechanism 'Suppression of Undesired Chemicals using Contrast-Enhancing Singlet States' (SUCCESS) and we demonstrate it in vitro for three target molecules relevant to neuroscience: aspartate, threonine and glutamine.
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Affiliation(s)
- Stephen J Devience
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St, Cambridge, MA, 02138, USA
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17
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McLean MA, Sun A, Bradstreet TE, Schaeffer AK, Liu H, Iannone R, Herman G, Railkar RA, Joubert I, Gillard JH, Price SJ, Griffiths JR. Repeatability of edited lactate and other metabolites in astrocytoma at 3T. J Magn Reson Imaging 2012; 36:468-75. [PMID: 22535478 DOI: 10.1002/jmri.23673] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 03/09/2012] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To assess the repeatability of measurement of lactate and other metabolites in tumors using magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS MRS with spectral editing for lactate was performed on 10 patients with astrocytoma (two Grade III, eight Grade IV) using an 8-channel receive coil at 3T. Lactate, lipid, choline, creatine, and N-acetyl aspartate (NAA) signals were measured in regions of tumor and contralateral white matter. Metabolites were quantified relative to unsuppressed water using LCModel fitting software. RESULTS The within-patient coefficients of variation were ≈16% (tumor lactate), 6%-8% (tumor choline and contralateral choline, creatine, and NAA), and 22% (tumor lipid). As expected due to their low concentration in normal tissue, lactate and lipid were not reliably detected in white matter but were found at high levels in most tumors. NAA and creatine were lower in tumors than in normal white matter, and choline varied between above- and below-normal values. No consistent short-term variation in metabolite levels was observed, despite differences in the time elapsed since administration of contrast agent. CONCLUSION MRS appears repeatable enough to provide longitudinal measures of metabolite content in tumors and contralateral tissue in the brain in vivo.
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Affiliation(s)
- Mary A McLean
- Cancer Research UK Cambridge Research Institute, Li Ka Shing Centre, Cambridge, UK.
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18
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Choi C, Ganji SK, DeBerardinis RJ, Dimitrov IE, Pascual JM, Bachoo R, Mickey BE, Malloy CR, Maher EA. Measurement of glycine in the human brain in vivo by 1H-MRS at 3 T: application in brain tumors. Magn Reson Med 2011; 66:609-18. [PMID: 21394775 DOI: 10.1002/mrm.22857] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/21/2010] [Accepted: 01/10/2011] [Indexed: 01/27/2023]
Abstract
Glycine is a key metabolic intermediate required for the synthesis of proteins, nucleic acids, and other molecules, and its detection in cancer could, therefore, provide biologically relevant information about the growth of the tumor. Here, we report measurement of glycine in human brain and gliomas by an optimized point-resolved spectroscopy sequence at 3 T. Echo time dependence of the major obstacle, myo-inositol (mI) multiplet, was investigated with numerical simulations, incorporating the 3D volume localization. The simulations indicated that a subecho pair (TE(1) , TE(2) ) = (60, 100) ms permits detection of both glycine and mI with optimum selectivity. In vivo validation of the optimized point-resolved spectroscopy was conducted on the right parietal cortex of five healthy volunteers. Metabolite signals estimated from LC Model were normalized with respect to the brain water signal, and the concentrations were evaluated assuming the total creatine concentration at 8 mM. The glycine concentration was estimated as 0.6 ± 0.1 mM (mean ± SD, n = 5), with a mean Cramér-Rao lower bound of 9 ± 1%. The point-resolved spectroscopy sequence was applied to measure the glycine levels in patients with glioblastoma multiforme. Metabolite concentrations were obtained using the water signal from the tumor mass. The study revealed that a subset of human gliomas contains glycine levels elevated 1.5-8 fold relative to normal.
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Affiliation(s)
- Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
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Xin L, Gambarota G, Duarte JMN, Mlynárik V, Gruetter R. Direct in vivo measurement of glycine and the neurochemical profile in the rat medulla oblongata. NMR IN BIOMEDICINE 2010; 23:1097-1102. [PMID: 20963803 DOI: 10.1002/nbm.1537] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The medulla oblongata (MO) contains a high density of glycinergic synapses and a particularly high concentration of glycine. The aims of this study were to measure directly in vivo the neurochemical profile, including glycine, in MO using a spin-echo-based (1)H MRS sequence at TE = 2.8 ms and to compare it with three other brain regions (cortex, striatum and hippocampus) in the rat. Glycine was quantified in MO at TE = 2.8 ms with a Cramér-Rao lower bound (CRLB) of approximately 5%. As a result of the relatively low level of glycine in the other three regions, the measurement of glycine was performed at TE = 20 ms, which provides a favorable J-modulation of overlapping myo-inositol resonance. The other 14 metabolites composing the neurochemical profile were quantified in vivo in MO with CRLBs below 25%. Absolute concentrations of metabolites in MO, such as glutamate, glutamine, γ-aminobutyrate, taurine and glycine, were in the range of previous in vitro quantifications in tissue extracts. Compared with the other regions, MO had a three-fold higher glycine concentration, and was characterised by reduced (p < 0.001) concentrations of glutamate (-50 ± 4%), glutamine (-54 ± 3%) and taurine (-78 ± 3%). This study suggests that the functional specialisation of distinct brain regions is reflected in the neurochemical profile.
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Affiliation(s)
- Lijing Xin
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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20
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Choi C, Douglas D, Hawesa H, Jindal A, Storey C, Dimitrov I. Measurement of glycine in human prefrontal brain by point-resolved spectroscopy at 7.0 tesla in vivo. Magn Reson Med 2010; 62:1305-10. [PMID: 19780175 DOI: 10.1002/mrm.22125] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Measurement of glycine in human frontal brain by an optimized point-resolved spectroscopy sequence at 7 T is reported. Echo time dependencies of the overlapping coupled resonances of myo-inositol, free choline, and threonine were investigated with density matrix simulations, incorporating the slice-selective radiofrequency and gradient pulses. The numerical simulations indicated that the selectivity of the 3.55-ppm glycine singlet is maximized at (TE(1), TE(2)) = (101, 51) ms. Phantom experiments indicated that the myo-inositol peak amplitude between 3.5 and 3.6 ppm is reduced by a factor of 30 following the optimized point-resolved spectroscopy, as predicted by the simulation. From LCModel analyses, the glycine concentration in the medial prefrontal cortex in healthy adults was estimated, with a mean Cramér-Rao lower bound of 7 +/- 1% (mean +/- standard deviation; n = 7), to be 0.8 +/- 0.1 mM, with reference to total creatine at 8 mM.
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Affiliation(s)
- Changho Choi
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
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21
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Dong Z, Dreher W, Leibfritz D, Peterson BS. Challenges of using MR spectroscopy to detect neural progenitor cells in vivo. AJNR Am J Neuroradiol 2009; 30:1096-101. [PMID: 19357383 DOI: 10.3174/ajnr.a1557] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A recent report of detection of neural progenitor cells (NPCs) in living human brain by using in vivo proton MR spectroscopy ((1)H-MR spectroscopy) has sparked great excitement in the field of biomedicine because of its potential influence and utility in clinical neuroscience research. On the other hand, the method used and the findings described in the report also caused heated debate and controversy. In this article, we will briefly detail the reasons for the debate and controversy from the point of view of the in vivo (1)H-MR spectroscopy methodology and will propose some technical strategies in both data acquisition and data processing to improve the feasibility of detecting NPCs in future studies by using in vivo (1)H-MR spectroscopy.
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Affiliation(s)
- Z Dong
- Department of Psychiatry, Columbia University, New York, NY 10032, USA.
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22
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Marjanska M, Henry PG, Uğurbil K, Gruetter R. Editing through multiple bonds: Threonine detection. Magn Reson Med 2008; 59:245-51. [DOI: 10.1002/mrm.21492] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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Rodrigues TB, Cerdán S, García-Martín ML. A method to measure lactate recycling in cultured cells by edited 1H nuclear magnetic resonance spectroscopy. Anal Biochem 2007; 370:246-8. [PMID: 17889822 DOI: 10.1016/j.ab.2007.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 08/08/2007] [Accepted: 08/11/2007] [Indexed: 11/16/2022]
Affiliation(s)
- Tiago B Rodrigues
- Instituto de Investigaciones Biomédicas Alberto Sols, C.S.I.C./U.A.M., 28029 Madrid, Spain
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