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Lopez Kolkovsky AL, Carlier PG, Marty B, Meyerspeer M. Interleaved and simultaneous multi-nuclear magnetic resonance in vivo. Review of principles, applications and potential. NMR IN BIOMEDICINE 2022; 35:e4735. [PMID: 35352440 PMCID: PMC9542607 DOI: 10.1002/nbm.4735] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/03/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Magnetic resonance signals from different nuclei can be excited or received at the same time,rendering simultaneous or rapidly interleaved multi-nuclear acquisitions feasible. The advan-tages are a reduction of total scan time compared to sequential multi-nuclear acquisitions or that additional information from heteronuclear data is obtained at thesame time and anatomical position. Information content can be qualitatively increased by delivering a more comprehensive MR-based picture of a transient state (such as an exercise bout). Also, combiningnon-proton MR acquisitions with 1 Hinformation (e.g., dynamic shim updates and motion correction) can be used to improve data quality during long scans and benefits image coregistration. This work reviews the literature on interleaved and simultaneous multi-nuclear MRI and MRS in vivo. Prominent use cases for this methodology in clinical and research applications are brain and muscle, but studies have also been carried out in other targets, including the lung, knee, breast and heart. Simultaneous multi-nuclear measurements in the liver and kidney have also been performed, but exclusively in rodents. In this review, a consistent nomenclature is proposed, to help clarify the terminology used for this principle throughout the literature on in-vivo MR. An overview covers the basic principles, the technical requirements on the MR scanner and the implementations realised either by MR system vendors or research groups, from the early days until today. Considerations regarding the multi-tuned RF coils required and heteronuclear polarisation interactions are briefly discussed, and fields for future in-vivo applications for interleaved multi-nuclear MR pulse sequences are identified.
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Affiliation(s)
- Alfredo L. Lopez Kolkovsky
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Pierre G. Carlier
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Benjamin Marty
- NMR Laboratory, Neuromuscular Investigation CenterInstitute of MyologyParisFrance
- NMR laboratoryCEA, DRF, IBFJParisFrance
| | - Martin Meyerspeer
- High‐Field MR Center, Center for Medical Physics and Biomedical EngineeringMedical University of ViennaViennaAustria
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Hatton SL, Pandey MK. Fat and Protein Combat Triggers Immunological Weapons of Innate and Adaptive Immune Systems to Launch Neuroinflammation in Parkinson's Disease. Int J Mol Sci 2022; 23:1089. [PMID: 35163013 PMCID: PMC8835271 DOI: 10.3390/ijms23031089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 01/27/2023] Open
Abstract
Parkinson's disease (PD) is the second-most common neurodegenerative disease in the world, affecting up to 10 million people. This disease mainly happens due to the loss of dopaminergic neurons accountable for memory and motor function. Partial glucocerebrosidase enzyme deficiency and the resultant excess accumulation of glycosphingolipids and alpha-synuclein (α-syn) aggregation have been linked to predominant risk factors that lead to neurodegeneration and memory and motor defects in PD, with known and unknown causes. An increasing body of evidence uncovers the role of several other lipids and their association with α-syn aggregation, which activates the innate and adaptive immune system and sparks brain inflammation in PD. Here, we review the emerging role of a number of lipids, i.e., triglyceride (TG), diglycerides (DG), glycerophosphoethanolamines (GPE), polyunsaturated fatty acids (PUFA), sphingolipids, gangliosides, glycerophospholipids (GPL), and cholesterols, and their connection with α-syn aggregation as well as the induction of innate and adaptive immune reactions that trigger neuroinflammation in PD.
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Affiliation(s)
- Shelby Loraine Hatton
- Cincinnati Children’s Hospital Medical Center, Division of Human Genetics, 3333 Burnet Avenue, Cincinnati, OH 45229, USA;
| | - Manoj Kumar Pandey
- Cincinnati Children’s Hospital Medical Center, Division of Human Genetics, 3333 Burnet Avenue, Cincinnati, OH 45229, USA;
- Department of Pediatrics, Division of Human Genetics, College of Medicine, University of Cincinnati, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
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Zhang IW, Curto A, López-Vicario C, Casulleras M, Duran-Güell M, Flores-Costa R, Colsch B, Aguilar F, Aransay AM, Lozano JJ, Hernández-Tejero M, Toapanta D, Fernández J, Arroyo V, Clària J. Mitochondrial dysfunction governs immunometabolism in leukocytes of patients with acute-on-chronic liver failure. J Hepatol 2022; 76:93-106. [PMID: 34450236 DOI: 10.1016/j.jhep.2021.08.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 08/04/2021] [Accepted: 08/04/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND & AIMS Patients with acute-on-chronic liver failure (ACLF) present a systemic hyperinflammatory response associated with increased circulating levels of small-molecule metabolites. To investigate whether these alterations reflect inadequate cell energy output, we assessed mitochondrial morphology and central metabolic pathways with emphasis on the tricarboxylic acid (TCA) cycle in peripheral leukocytes from patients with acutely decompensated (AD) cirrhosis, with and without ACLF. METHODS The study included samples from patients with AD cirrhosis (108 without and 128 with ACLF) and 41 healthy individuals. Leukocyte mitochondrial ultrastructure was visualized by transmission electron microscopy and cytosolic and mitochondrial metabolic fluxes were determined by assessing NADH/FADH2 production from various substrates. Plasma GDF15 and FGF21 were determined by Luminex and acylcarnitines by LC-MS/MS. Gene expression was analyzed by RNA-sequencing and PCR-based glucose metabolism profiler array. RESULTS Mitochondrial ultrastructure in patients with advanced cirrhosis was distinguished by cristae rarefication and swelling. The number of mitochondria per leukocyte was higher in patients, accompanied by a reduction in their size. Increased FGF21 and C6:0- and C8:0-carnitine predicted mortality whereas GDF15 strongly correlated with a gene set signature related to leukocyte activation. Metabolic flux analyses revealed increased energy production in mononuclear leukocytes from patients with preferential involvement of extra-mitochondrial pathways, supported by upregulated expression of genes encoding enzymes of the glycolytic and pentose phosphate pathways. In patients with ACLF, mitochondrial function analysis uncovered break-points in the TCA cycle at the isocitrate dehydrogenase and succinate dehydrogenase level, which were bridged by anaplerotic reactions involving glutaminolysis and nucleoside metabolism. CONCLUSIONS Our findings provide evidence at the cellular, organelle and biochemical levels that severe mitochondrial dysfunction governs immunometabolism in leukocytes from patients with AD cirrhosis and ACLF. LAY SUMMARY Patients at advanced stages of liver disease have dismal prognosis due to vital organ failures and the lack of treatment options. In this study, we report that the functioning of mitochondria, which are known as the cell powerhouse, is severely impaired in leukocytes of these patients, probably as a consequence of intense inflammation. Mitochondrial dysfunction is therefore a hallmark of advanced liver disease.
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Affiliation(s)
- Ingrid W Zhang
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Anna Curto
- European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Cristina López-Vicario
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Mireia Casulleras
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Marta Duran-Güell
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Roger Flores-Costa
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Benoit Colsch
- Laboratoire d'Etude du Metabolisme des Medicaments, CEA, INRA, Universite Paris Saclay, MetaboHUB, F-91191 Gif-sur-Yvette, France
| | - Ferran Aguilar
- European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Ana M Aransay
- CIC bioGUNE, Parque Tecnológico de Bizkaia, Derio, Bizkaia, Spain; CIBERehd, Barcelona, Spain
| | | | | | - David Toapanta
- Liver ICU, Liver Unit, Hospital Clínic-IDIBAPS, Barcelona, Spain
| | - Javier Fernández
- European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain; CIBERehd, Barcelona, Spain; Liver ICU, Liver Unit, Hospital Clínic-IDIBAPS, Barcelona, Spain
| | - Vicente Arroyo
- European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain
| | - Joan Clària
- Biochemistry and Molecular Genetics Service, Hospital Clínic-IDIBAPS, Barcelona, Spain; European Foundation for the Study of Chronic Liver Failure (EF Clif) and Grifols Chair, Barcelona, Spain; CIBERehd, Barcelona, Spain; Department of Biomedical Sciences, University of Barcelona, Barcelona, Spain.
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Purvis LAB, Clarke WT, Valkovič L, Levick C, Pavlides M, Barnes E, Cobbold JF, Robson MD, Rodgers CT. Phosphodiester content measured in human liver by in vivo 31 P MR spectroscopy at 7 tesla. Magn Reson Med 2017; 78:2095-2105. [PMID: 28244131 PMCID: PMC5697655 DOI: 10.1002/mrm.26635] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 01/13/2017] [Accepted: 01/17/2017] [Indexed: 12/19/2022]
Abstract
Purpose Phosphorus (31P) metabolites are emerging liver disease biomarkers. Of particular interest are phosphomonoester and phosphodiester (PDE) “peaks” that comprise multiple overlapping resonances in 31P spectra. This study investigates the effect of improved spectral resolution at 7 Tesla (T) on quantifying hepatic metabolites in cirrhosis. Methods Five volunteers were scanned to determine metabolite T1s. Ten volunteers and 11 patients with liver cirrhosis were scanned at 7T. Liver spectra were acquired in 28 min using a 16‐channel 31P array and 3D chemical shift imaging. Concentrations were calculated using γ‐adenosine‐triphosphate (γ‐ATP) = 2.65 mmol/L wet tissue. Results T1 means ± standard deviations: phosphatidylcholine 1.05 ± 0.28 s, nicotinamide‐adenine‐dinucleotide (NAD+) 2.0 ± 1.0 s, uridine‐diphosphoglucose (UDPG) 3.3 ± 1.4 s. Concentrations in healthy volunteers: α‐ATP 2.74 ± 0.11 mmol/L wet tissue, inorganic phosphate 2.23 ± 0.20 mmol/L wet tissue, glycerophosphocholine 2.34 ± 0.46 mmol/L wet tissue, glycerophosphoethanolamine 1.50 ± 0.28 mmol/L wet tissue, phosphocholine 1.06 ± 0.16 mmol/L wet tissue, phosphoethanolamine 0.77 ± 0.14 mmol/L wet tissue, NAD+ 2.37 ± 0.14 mmol/L wet tissue, UDPG 2.00 ± 0.22 mmol/L wet tissue, phosphatidylcholine 1.38 ± 0.31 mmol/L wet tissue. Inorganic phosphate and phosphatidylcholine concentrations were significantly lower in patients; glycerophosphoethanolamine concentrations were significantly higher (P < 0.05). Conclusion We report human in vivo hepatic T1s for phosphatidylcholine, NAD+, and UDPG for the first time at 7T. Our protocol allows high signal‐to‐noise, repeatable measurement of metabolite concentrations in human liver. The splitting of PDE into its constituent peaks at 7T may allow more insight into changes in metabolism. Magn Reson Med 78:2095–2105, 2017. © 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)
- Lucian A B Purvis
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom
| | - William T Clarke
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom
| | - Ladislav Valkovič
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom.,Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Christina Levick
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom
| | - Michael Pavlides
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom.,Translational Gastroenterology Unit, University of Oxford, United Kingdom
| | - Eleanor Barnes
- Translational Gastroenterology Unit, University of Oxford, United Kingdom
| | - Jeremy F Cobbold
- Translational Gastroenterology Unit, University of Oxford, United Kingdom
| | - Matthew D Robson
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom
| | - Christopher T Rodgers
- Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Level 0, John Radcliffe Hospital, Oxford, United Kingdom
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Carlbom L, Weis J, Johansson L, Korsgren O, Ahlström H. Pre-transplantation 31P-magnetic resonance spectroscopy for quality assessment of human pancreatic grafts - A feasibility study. Magn Reson Imaging 2017; 39:98-102. [PMID: 28188872 DOI: 10.1016/j.mri.2017.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/14/2017] [Accepted: 02/07/2017] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To investigate the feasibility of using 31P-MRS for objective non-invasive quality assessment of human pancreas grafts prior to transplantation or islet isolation. MATERIALS AND METHODS Pancreata from 5 human donors, 3 males and 2 females, aged 49-78years, with body mass index (BMI) 22-31kg/m2, were included. Pancreata were perfused with histidine-tryptophan-ketoglutarate solution during procurement and stored in hypothermic condition (4°C) for 21-44h. During the period of hypothermic storage repeated spectra were obtained for each graft by 31P-MRS (1.5Tesla) to measure the cold ischemia time (CIT) dependent changes of the phosphorous metabolites adenosine triphosphate (ATP), phosphomonoesters (PME), phosphodiesters (PDE) and inorganic phosphate (Pi), in the grafts. Graft temperature was measured immediately before and after MR-examination. Reference spectrum for non-viable tissue was obtained after graft exposure to room temperature. RESULTS PME/Pi, PDE/Pi and ATP/Pi spectral intensities ratios decreased with increasing CIT, reflecting the decreased viability of the grafts. PME/Pi ratio was the most discriminatory variable at prolonged CIT. 31P-MRS could be performed without significantly increasing graft temperature. CONCLUSIONS 31P-MRS may provide quantitative parameters for evaluating graft viability ex vivo, and is a promising tool for objective non-invasive assessment of the quality of human pancreas grafts prior to transplantation or islet isolation.
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Affiliation(s)
- Lina Carlbom
- Department of Surgical Sciences, Uppsala University, Sweden..
| | - Jan Weis
- Department of Surgical Sciences, Uppsala University, Sweden
| | - Lars Johansson
- Department of Surgical Sciences, Uppsala University, Sweden
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Sweden
| | - Håkan Ahlström
- Department of Surgical Sciences, Uppsala University, Sweden
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Valkovič L, Chmelík M, Krššák M. In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism. Anal Biochem 2017; 529:193-215. [PMID: 28119063 PMCID: PMC5478074 DOI: 10.1016/j.ab.2017.01.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 01/18/2023]
Abstract
In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.
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Affiliation(s)
- Ladislav Valkovič
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Oxford, United Kingdom; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia.
| | - Marek Chmelík
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Institute for Clinical Molecular MRI in Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria
| | - Martin Krššák
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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van der Kemp WJM, Stehouwer BL, Runge JH, Wijnen JP, Nederveen AJ, Luijten PR, Klomp DWJ. Glycerophosphocholine and Glycerophosphoethanolamine Are Not the Main Sources of the In Vivo (31)P MRS Phosphodiester Signals from Healthy Fibroglandular Breast Tissue at 7 T. Front Oncol 2016; 6:29. [PMID: 26913240 PMCID: PMC4753293 DOI: 10.3389/fonc.2016.00029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/28/2016] [Indexed: 11/13/2022] Open
Abstract
PURPOSE The identification of the phosphodiester (PDE) (31)P MR signals in the healthy human breast at ultra-high field. METHODS In vivo (31)P MRS measurements at 7 T of the PDE signals in the breast were performed investigating the chemical shifts, the transverse- and the longitudinal relaxation times. Chemical shifts and transverse relaxation times were compared with non-ambiguous PDE signals from the liver. RESULTS The chemical shifts of the PDE signals are shifted -0.5 ppm with respect to glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE), and the transverse and longitudinal relaxation times for these signals are a factor 3 to 4 shorter than expected for aqueous GPC and GPE. CONCLUSION The available experimental evidence suggests that GPC and GPE are not the main source of the PDE signals measured in fibroglandular breast tissue at 7 T. These signals may predominantly originate from mobile phospholipids.
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Affiliation(s)
| | | | - Jurgen H Runge
- Radiology, Academic Medical Center , Amsterdam , Netherlands
| | - Jannie P Wijnen
- Radiology, University Medical Center Utrecht , Utrecht , Netherlands
| | | | - Peter R Luijten
- Radiology, University Medical Center Utrecht , Utrecht , Netherlands
| | - Dennis W J Klomp
- Radiology, University Medical Center Utrecht , Utrecht , Netherlands
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Tognarelli JM, Dawood M, Shariff MI, Grover VP, Crossey MM, Cox IJ, Taylor-Robinson SD, McPhail MJ. Magnetic Resonance Spectroscopy: Principles and Techniques: Lessons for Clinicians. J Clin Exp Hepatol 2015; 5:320-8. [PMID: 26900274 PMCID: PMC4723643 DOI: 10.1016/j.jceh.2015.10.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/26/2015] [Indexed: 12/12/2022] Open
Abstract
Magnetic resonance spectroscopy (MRS) provides a non-invasive 'window' on biochemical processes within the body. Its use is no longer restricted to the field of research, with applications in clinical practice increasingly common. MRS can be conducted at high magnetic field strengths (typically 11-14 T) on body fluids, cell extracts and tissue samples, with new developments in whole-body magnetic resonance imaging (MRI) allowing clinical MRS at the end of a standard MRI examination, obtaining functional information in addition to anatomical information. We discuss the background physics the busy clinician needs to know before considering using the technique as an investigative tool. Some potential applications of hepatic and cerebral MRS in chronic liver disease are also discussed.
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Key Words
- CPMG, Carr-Purcell-Meiboom-Gill sequence
- CSI, chemical shift imaging
- FID, free induction decay
- K, Kelvin
- KEGG, Kyoto Encyclopedia for Genes and Genomes
- MR, magnetic resonance
- MRI, magnetic resonance imaging
- MRS, magnetic resonance spectroscopy
- MSEA, metabolite set enrichment analysis
- NMR, nuclear magnetic resonance
- NOESY, nuclear Overhauser enhancement spectroscopy
- PC, principal components
- PCA, principal components analysis
- PLS-DA, partial least squared discriminant analysis
- PRESS, point-resolved spectroscopy
- STEAM, stimulated echo acquisition mode
- T, Tesla
- T1, spin-lattice relaxation
- T2, spin-spin relaxation
- TE, echo time
- TMAO, trimethylamine N-oxide
- TR, repetition time
- magnetic resonance imaging
- magnetic resonance spectroscopy
- metabolomics
- nuclear magnetic resonance
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Affiliation(s)
- Joshua M. Tognarelli
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
- Address for correspondence: Joshua Tognarelli, Liver Unit, Department of Medicine, 10th Floor QEQM Wing, St Mary's Hospital, Imperial College London, Praed Street, London W2 1NY, United Kingdom. Tel.: +44 207 886 6454; fax: +44 207 402 2796.Liver Unit, Department of Medicine, 10th Floor QEQM Wing, St Mary's Hospital, Imperial College LondonPraed StreetLondonW2 1NYUnited Kingdom
| | - Mahvish Dawood
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mohamed I.F. Shariff
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Vijay P.B. Grover
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mary M.E. Crossey
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - I. Jane Cox
- The Foundation for Liver Research, Institute of Hepatology, 69-75 Chenies Mews, London WC1E 6HX, United Kingdom
| | - Simon D. Taylor-Robinson
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mark J.W. McPhail
- Liver Unit, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
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Chmelík M, Valkovič L, Wolf P, Bogner W, Gajdošík M, Halilbasic E, Gruber S, Trauner M, Krebs M, Trattnig S, Krššák M. Phosphatidylcholine contributes to in vivo (31)P MRS signal from the human liver. Eur Radiol 2015; 25:2059-66. [PMID: 25576233 DOI: 10.1007/s00330-014-3578-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/13/2014] [Accepted: 12/18/2014] [Indexed: 12/15/2022]
Abstract
OBJECTIVES To demonstrate the overlap of the hepatic and bile phosphorus ((31)P) magnetic resonance (MR) spectra and provide evidence of phosphatidylcholine (PtdC) contribution to the in vivo hepatic (31)P MRS phosphodiester (PDE) signal, suggested in previous reports to be phosphoenolpyruvate (PEP). METHODS Phantom measurements to assess the chemical shifts of PEP and PtdC signals were performed at 7 T. A retrospective analysis of hepatic 3D (31)P MR spectroscopic imaging (MRSI) data from 18 and five volunteers at 3 T and 7 T, respectively, was performed. Axial images were inspected for the presence of gallbladder, and PDE signals in representative spectra were quantified. RESULTS Phantom experiments demonstrated the strong pH-dependence of the PEP chemical shift and proved the overlap of PtdC and PEP (~2 ppm relative to phosphocreatine) at hepatic pH. Gallbladder was covered in seven of 23 in vivo 3D-MRSI datasets. The PDE(gall)/γ-ATP(liver) ratio was 4.8-fold higher (p = 0.001) in the gallbladder (PDE(gall)/γ-ATP(liver) = 3.61 ± 0.79) than in the liver (PDE(liver)/γ-ATP(liver) = 0.75 ± 0.15). In vivo 7 T (31)P MRSI allowed good separation of PDE components. The gallbladder is a strong source of contamination in adjacent (31)P MR hepatic spectra due to biliary phosphatidylcholine. CONCLUSIONS In vivo (31)P MR hepatic signal at 2.06 ppm may represent both phosphatidylcholine and phosphoenolpyruvate, with a higher phosphatidylcholine contribution due to its higher concentration. KEY POINTS • In vivo (31)P MRS from the gallbladder shows a dominant biliary phosphatidylcholine signal at 2.06 ppm. • Intrahepatic (31)P MRS signal at 2.06 ppm may represent both intrahepatic phosphatidylcholine and phosphoenolpyruvate. • In vivo (31)P MRS has the potential to monitor hepatic phosphatidylcholine.
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Affiliation(s)
- Marek Chmelík
- MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
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Chmelik M, Považan M, Krššák M, Gruber S, Tkačov M, Trattnig S, Bogner W. In vivo (31)P magnetic resonance spectroscopy of the human liver at 7 T: an initial experience. NMR IN BIOMEDICINE 2014; 27:478-85. [PMID: 24615903 DOI: 10.1002/nbm.3084] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 12/11/2013] [Accepted: 01/07/2014] [Indexed: 05/12/2023]
Abstract
Phosphorus ((31) P) MRS is a powerful tool for the non-invasive investigation of human liver metabolism. Four in vivo (31) P localization approaches (single voxel image selected in vivo spectroscopy (3D-ISIS), slab selective 1D-ISIS, 2D chemical shift imaging (CSI), and 3D-CSI) with different voxel volumes and acquisition times were demonstrated in nine healthy volunteers. Localization techniques provided comparable signal-to-noise ratios normalized for voxel volume and acquisition time differences, Cramer-Rao lower bounds (8.7 ± 3.3%1D-ISIS , 7.6 ± 2.5%3D-ISIS , 8.6 ± 4.2%2D-CSI , 10.3 ± 2.7%3D-CSI ), and linewidths (50 ± 24 Hz1D-ISIS , 34 ± 10 Hz3D-ISIS , 33 ± 10 Hz2D-CSI , 34 ± 11 Hz3D-CSI ). Longitudinal (T1 ) relaxation times of human liver metabolites at 7 T were assessed by 1D-ISIS inversion recovery in the same volunteers (n = 9). T1 relaxation times of hepatic (31) P metabolites at 7 T were the following: phosphorylethanolamine - 4.41 ± 1.55 s; phosphorylcholine - 3.74 ± 1.31 s; inorganic phosphate - 0.70 ± 0.33 s; glycerol 3-phosphorylethanolamine - 6.19 ± 0.91 s; glycerol 3-phosphorylcholine - 5.94 ± 0.73 s; γ-adenosine triphosphate (ATP) - 0.50 ± 0.08 s; α-ATP - 0.46 ± 0.07 s; β-ATP - 0.56 ± 0.07 s. The improved spectral resolution at 7 T enabled separation of resonances in the phosphomonoester and phosphodiester spectral region as well as nicotinamide adenine dinucleotide and uridine diphosphoglucose signals. An additional resonance at 2.06 ppm previously assigned to phosphoenolpyruvate or phosphatidylcholine is also detectable. These are the first (31) P metabolite relaxation time measurements at 7 T in human liver, and they will help in the exploration of new, exciting questions in metabolic research with 7 T MR.
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Affiliation(s)
- Marek Chmelik
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
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11
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Non-alcoholic fatty liver disease: spectral patterns observed from an in vivo phosphorus magnetic resonance spectroscopy study. J Hepatol 2014; 60:809-15. [PMID: 24291241 DOI: 10.1016/j.jhep.2013.11.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 11/10/2013] [Accepted: 11/19/2013] [Indexed: 01/28/2023]
Abstract
BACKGROUND & AIMS Liver biopsy is the gold standard for diagnosing non-alcoholic fatty liver disease (NAFLD) but with practical constraints. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) allows in vivo assessment of hepatocellular metabolism and has shown potential for biochemical differentiation in diffuse liver disease. Our aims were to describe spectroscopic signatures in biopsy-proven NAFLD and to determine diagnostic performance of (31)P-MRS for non-alcoholic steatohepatitis (NASH). METHODS (31)P-MRS was performed in 151 subjects, comprised of healthy controls (n=19) and NAFLD patients with non-NASH (n=37) and NASH (n=95). Signal intensity ratios for phosphomonoesters (PME) including phosphoethanolamine (PE), phosphodiesters (PDE) including glycerophosphocholine (GPC), total nucleotide triphosphate (NTP) including α-NTP, and inorganic phosphate (Pi), expressed relative to total phosphate (TP) or [PME+PDE] and converted to percentage, were obtained. RESULTS Compared to controls, both NAFLD groups had increased PDE/TP (p<0.001) and decreased Pi/TP (p=0.011). Non-NASH patients showed decreased PE/[PME+PDE] (p=0.048), increased GPC/[PME+PDE] (p<0.001), and normal NTP/TP and α-NTP/TP. Whereas, NASH patients had normal PE/[PME+PDE] and GPC/[PME+PDE], but decreased NTP/TP (p=0.004) and α-NTP/TP (p<0.001). The latter was significantly different between non-NASH and NASH (p=0.047) and selected as discriminating parameter, with area under the receiver-operating characteristics curve of 0.71 (95% confidence interval, 0.62-0.79). An α-NTP/TP cutoff of 16.36% gave 91% sensitivity and cutoff of 10.57% gave 91% specificity for NASH. CONCLUSIONS (31)P-MRS shows distinct biochemical changes in different NAFLD states, and has fair diagnostic accuracy for NASH.
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Jiang T, Liu S, Xiao X, Tao X, Liu G, Wang J. RETRACTED ARTICLE: Diagnosis of rejection after liver transplantation: use of phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS). Abdom Radiol (NY) 2012; 37:788-94. [PMID: 23166917 DOI: 10.1007/s00261-008-9451-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND In vivo hepatic phosphorus-31 magnetic resonance spectroscopy (31)P-MRS) provides non-invasive information about phospholipid metabolism. AIMS To delineate (31)P-MRS abnormalities in patients with chronic rejection and to characterize spectral changes by pathology. PATIENTS AND METHODS Sixty-six liver transplant recipients (18 with chronic rejection and 48 with normal graft function) and 38 controls (23 healthy volunteers and fifteen patients with biliary duct stricture) were studied with in vivo (31)P-MRS. All the data and peak values were calibrated and calculated by the software of spectroscopy analysis GE, and the pH values were calculated by the Malloy's formula, then the peak area ratios and altitudes of metabolites relative to adenosine triphosphate (β-ATP)and phosphate (Pi) were measured. RESULTS (a) The peak area ratios and altitudes of PME and PDE in biliary duct stricture group and chronic rejection group were higher than those of healthy volunteer group and normal graft function group. Patients with chronic rejection had significant differences in the peak area ratios of PME: β-ATP (P < 0.05) and PDE: β-ATP (P < 0.05) and in the altitudes of PME: β-ATP (P < 0.05) as compared with the other groups. (b) The ratios of β-ATP/Pi decreased in biliary duct stricture group, while they increased in chronic rejection group. There was no difference between the four groups. There were similar changes in the ratios of PME/Pi, but there was significant difference between the chronic rejection group and the other three groups. (c) pH values increased in biliary duct stricture group and chronic rejection group, though the difference was not significant with the healthy control group. (d) Histological specimens showed focal loss of hepatocytes, degeneration, and hepatocytic atrophy. CONCLUSIONS (31)P-MRS imaging is valuable in detecting the metabolism of the liver after transplantation, and suggests that further investigation of alterations in the phospholipid metabolism may be a useful future direction of research.
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Affiliation(s)
- Tao Jiang
- Department of Radiology, Changzheng Hospital, The Second Military Medical University, Feng Yang Road 415, Shanghai, China
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13
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Solanky BS, Sanchez-Canon GJ, Cobbold JFL, Taylor-Robinson SD, Bell JD, Scudamore CL, Ross E, Holder JC, So PW, Cox IJ. Metabolic profiling of the rat liver after chronic ingestion of alpha-naphthylisothiocyanate using in vivo and ex vivo magnetic resonance spectroscopy. Toxicol Sci 2012; 126:306-16. [PMID: 22262563 DOI: 10.1093/toxsci/kfs019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Certain human diseases affecting the biliary tree can be modeled in rats by ingestion of the hepatobiliary toxin alpha-naphthylisothiocyanate (ANIT). Phosphorus magnetic resonance spectroscopy (MRS) allows the noninvasive monitoring of cell dynamics through detection of phosphodiesters (PDE) and phosphomonoesters (PME). Hepatic (31)P MRS techniques were therefore used to study the toxic effects of low-dose chronic ANIT ingestion, with a view toward providing biomarkers sensitive to hepatobiliary dysfunction and cholestatic liver injury. Rats were fed an ANIT supplemented diet at three doses (ANIT_0.05%, ANIT_0.04%, and ANIT_0.025%) for 2 weeks. Data from in vivo MRS were compared with results from pair-fed controls (PFCs). Blood and tissue samples were collected at 2 weeks for clinical chemistry, histology, and (1)H magic angle spinning MRS. Increases in PDE, relative to total phosphorus (tPh), were detected in both the ANIT_0.05% and ANIT_0.04% groups (0.07 ± 0.01 and 0.08 ± 0.01, respectively) relative to PFC groups (0.03 ± 0.01 and 0.05 ± 0.01, respectively). An increase in PME/tPh was observed in the ANIT_0.05% group only (0.17 ± 0.02) relative to PFC_0.05% (0.12 ± 0.01). Ex vivo (1)H MRS findings supported this, wherein measured phosphocholines (PCs) were increased in ANIT_0.05% and ANIT_0.04% groups. Increases in relative total choline (tCho) distinguished the ANIT_0.05% group from the ANIT_0.04% group. Markers of hepatotoxicity such as raised total bilirubin and alkaline phosphatase were found at all ANIT doses. Histological findings included a dose-related increase in both severity of biliary hyperplasia and focal hepatocellular necrosis. Here, we found that ANIT-induced moderate hepatobiliary dysfunction was associated with a relative increase in phosphodiesters in vivo and PCs ex vivo. Raised PME/tPh in vivo and tCho ex vivo were also present at high doses corresponding to a higher incidence of marked biliary hyperplasia and moderate hepatocellular necrosis.
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Affiliation(s)
- Bhavana S Solanky
- Imaging Sciences Department, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK.
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Hecht EM, Lee RF, Taouli B, Sodickson DK. Perspectives on body MR imaging at ultrahigh field. Magn Reson Imaging Clin N Am 2008; 15:449-65, viii. [PMID: 17893062 DOI: 10.1016/j.mric.2007.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
As investigators consider approaching the challenge of MR imaging at field strengths above 3T, do they follow the same paradigm, and continue to work around the same problems they have encountered thus far at 3T, or do they explore other ways of answering the clinical questions more effectively and more comprehensively? The most immediate problems of imaging at ultrahigh field strength are not unfamiliar, as many of them are still pressing issues at 3T: radiofrequency coils, B1 homogeneity, specific absorption rate, safety, B0 field homogeneity, alterations in tissue contrast, and chemical shift. In this article, these issues are briefly reviewed in terms of how they may affect image quality at field strengths beyond 3T. The authors propose various approaches to overcoming the challenges, and discuss potential applications of ultrahigh field MR imaging as it applies to specific abdominal, pelvic, peripheral vascular, and breast imaging protocols.
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Affiliation(s)
- Elizabeth M Hecht
- Department of Radiology, New York University School of Medicine, 560 First Avenue, New York, NY 10016, USA.
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15
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Lim AKP, Patel N, Hamilton G, Mylvahan K, Kuo YT, Goldin RD, Taylor-Robinson SD. 31P MR Spectroscopy in Assessment of Response to Antiviral Therapy for Hepatitis C Virus–Related Liver Disease. AJR Am J Roentgenol 2007; 189:819-23. [PMID: 17885051 DOI: 10.2214/ajr.07.2418] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE An increase in the ratio of phosphomonoester (PME) to phosphodiester (PDE) during 31P MR spectroscopy of the liver has been observed with increasing severity of hepatitis C-related liver disease. The purpose of this study was to investigate the utility of 31P MR spectroscopy as a biomarker of response to interferon and ribavirin treatment. SUBJECTS AND METHODS Forty-seven patients with biopsy-proven hepatitis C undergoing viral eradication treatment with interferon and ribavirin underwent hepatic 31P MR spectroscopy at 1.5 T (voxel size, 70 x 70 x 70 mm; TR, 10,000; number of signals averaged, 48). All underwent baseline imaging before treatment and repeated imaging at 6-month intervals after the start of treatment. RESULTS All patients underwent follow-up imaging 6 months after the start of treatment; 25 patients, 12 months; and 10 patients, 18 months after the start of treatment. According to the Ishak histologic scoring system, nine patients had mild hepatitis; 30 patients, moderate to severe hepatitis; and eight patients, cirrhosis. Thirty-two patients responded to antiviral treatment. Among these patients, 25 had a decrease in PME/PDE ratio on follow-up imaging. Among responders the mean baseline PME/PDE ratio decreased from 0.27 +/- 0.02 (standard error) to 0.16 +/- 0.01 after treatment (paired Student's t test, p < 0.001). Among the 15 virologic nonresponders, the ratios were similar in six patients; six other patients had an increase on follow-up imaging. In the latter nonresponder group, the mean baseline PME/PDE ratio was 0.21 +/- 0.03 compared with 0.31 +/- 0.08 after treatment (paired Student's t test, p =0.24). CONCLUSION The in vivo hepatic PME/PDE ratio decreased in patients with hepatitis C who responded to antiviral treatment and remained similar or increased in patients without a virologic response. These results suggest that PME and PDE can be used as biomarkers in a noninvasive test of response to treatment.
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Affiliation(s)
- Adrian K P Lim
- Department of Imaging Sciences, Faculty of Medicine, Imperial College London, Robert Steiner MRI Unit, MRC Clinical Sciences Centre, Hammersmith Hospital, Du Cane Rd., London W12 0HS, United Kingdom.
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Cox IJ, Sharif A, Cobbold JFL, Thomas HC, Taylor-Robinson SD. Current and future applications of in vitro magnetic resonance spectroscopy in hepatobiliary disease. World J Gastroenterol 2006; 12:4773-83. [PMID: 16937457 PMCID: PMC4087609 DOI: 10.3748/wjg.v12.i30.4773] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Nuclear magnetic resonance spectroscopy allows the study of cellular biochemistry and metabolism, both in the whole body in vivo and at higher magnetic field strengths in vitro. Since the technique is non-invasive and non-selective, magnetic resonance spectroscopy methodologies have been widely applied in biochemistry and medicine. In vitro magnetic resonance spectroscopy studies of cells, body fluids and tissues have been used in medical biochemistry to investigate pathophysiological processes and more recently, the technique has been used by physicians to determine disease abnormalities in vivo. This highlighted topic illustrates the potential of in vitro magnetic resonance spectroscopy in studying the hepatobiliary system. The role of in vitro proton and phosphorus magnetic resonance spectroscopy in the study of malignant and non-malignant liver disease and bile composition studies are discussed, particularly with reference to correlative in vivo whole-body magnetic resonance spectroscopy applications. In summary, magnetic resonance spectroscopy techniques can provide non-invasive biochemical information on disease severity and pointers to underlying pathophysiological processes. Magnetic resonance spectroscopy holds potential promise as a screening tool for disease biomarkers, as well as assessing therapeutic response.
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Affiliation(s)
- I Jane Cox
- Imaging Sciences Department, Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
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McKenzie EJ, Jackson M, Sun J, Volotovskyy V, Gruwel MLH. Monitoring the development of hepatocellular carcinoma in woodchucks using 31P-MRS. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2005; 18:201-5. [PMID: 16133593 DOI: 10.1007/s10334-005-0120-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2005] [Revised: 07/17/2005] [Accepted: 07/18/2005] [Indexed: 01/03/2023]
Abstract
The woodchuck is one of the only lab animal models of chronic viral hepatitis infection and the development of hepatocellular carcinoma. Using this model, changes in tissue energetics in the liver due to the development of hepatocellular carcinoma can be monitored by repeated magnetic resonance imaging and localized phosphorus spectroscopy. Age- and sex-matched control (n=5) and chronically infected (n=5) adult woodchucks were imaged four times in a six-month period in a 7-T horizontal-bore magnet. Using a custom-built doubly tunable quadrature volume coil, sagittal and axial FLASH images (128 x 128, slice thickness = 5 mm, TR/TE=1000/4.1, 8 averages) were acquired to locate the largest portion of the liver with the least amount of signal contamination from surrounding abdominal muscle. Two-dimensional 31P chemical-shift imaging (2D-CSI) was acquired (16 x 16 data matrix, 24 x 24 x 2 cm3, 1024 data points, 16 averages) for all animals. The extent of liver injury was determined using serum gamma glutamyltransferase (GGT). The livers of infected woodchucks showed a significant increase (p=0.01) in phosphomonoesters (PME):beta-adenosine triphosphate (NTP). Chronically infected woodchucks had higher levels of serum GGT compared to uninfected woodchucks (p=0.002). An increase in the PME:beta-NTP ratio indicates cellular proliferation within the malignant tumor.
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Affiliation(s)
- E J McKenzie
- National Research Council, Institute for Biodiagnostics, 435 Ellice Ave., Winnipeg, MB, R3B 1Y6, Canada.
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Khan SA, Cox IJ, Thillainayagam AV, Bansi DS, Thomas HC, Taylor-Robinson SD. Proton and phosphorus-31 nuclear magnetic resonance spectroscopy of human bile in hepatopancreaticobiliary cancer. Eur J Gastroenterol Hepatol 2005; 17:733-8. [PMID: 15947550 DOI: 10.1097/00042737-200507000-00007] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Hepatopancreaticobiliary cancers can be difficult to diagnose. Nuclear magnetic resonance (NMR) spectroscopy provides non-invasive information on phospholipid metabolism, and previous studies of liver tissue have highlighted changes in phospholipids in malignancy. We hypothesised that in-vitro NMR spectroscopy of human bile may provide independent diagnostic indices in cancer management through an assessment of the phospholipid content. DESIGN AND METHODS Bile samples from 24 patients were collected at endoscopic retrograde cholangiopancreatography and from one subject at cholecystectomy. Thirteen patients had cancer: pancreatic carcinoma (eight), cholangiocarcinoma (three) and metastatic liver disease (two). The remaining 12 patients had non-malignant pathology. In-vitro proton (H) and phosphorus-31 (P) NMR spectra were obtained from all samples using an 11.7 Tesla NMR spectroscopy system. RESULTS Complementary information was obtained from the H and P NMR spectra. Signals were assigned to phosphatidylcholine in both H and P NMR spectra. Phosphatidylcholine levels were significantly reduced in the bile from cancer patients when compared with bile from non-cancer patients (P=0.007). CONCLUSION These preliminary studies suggest that H and P NMR spectroscopy of bile may be used to detect differences in phospholipid content between cancer and non-cancer patients. This may have implications for the development of novel diagnostic strategies in hepatopancreaticobiliary cancers. Further larger-scale studies are warranted.
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Affiliation(s)
- Shahid A Khan
- Liver Unit, Division of Medicine, St Mary's Hospital Campus, Imperial College London, London, UK.
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Müllenbach R, Bennett A, Tetlow N, Patel N, Hamilton G, Cheng F, Chambers J, Howard R, Taylor-Robinson SD, Williamson C. ATP8B1 mutations in British cases with intrahepatic cholestasis of pregnancy. Gut 2005; 54:829-34. [PMID: 15888793 PMCID: PMC1774530 DOI: 10.1136/gut.2004.058115] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Intrahepatic cholestasis of pregnancy (ICP) affects approximately 0.7% of pregnancies in the UK and is associated with prematurity, fetal distress, and intrauterine death. Homozygous mutations in the ATP8B1 gene cause cholestasis with a normal serum gamma-glutamyl transpeptidase (gamma-GT), and have been reported in two forms of cholestasis: progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis (BRIC). AIMS To establish whether mutations in ATP8B1 are associated with ICP in British cases PATIENTS Sixteen well phenotyped women with ICP without raised gamma-GT were selected for sequence analysis. Subsequently, 182 patients and 120 controls were examined for the presence of the variants detected. METHODS All coding exons were sequenced in 16 cases. Eight ICP cases, including two women carrying a mutation, were investigated using in vivo hepatic (31)P magnetic resonance spectroscopy (MRS) RESULTS: Two heterozygous ATP8B1 transitions (208G>A and 2599C>T) that resulted in amino acid substitutions were identified; 208G>A was identified in three cases. MRS revealed an increased phosphodiester signal (Mann-Whitney U test, p = 0.03) and a decreased phosphomonoester/phosphodiester ratio (p = 0.04) in ICP cases compared with controls. CONCLUSIONS We were able to demonstrate ATP8B1 mutations in ICP. MRS studies suggest that susceptibility to ICP is associated with a relative rise in biliary phospholipid. These data also suggest that MRS may be used for non-invasive assessment of the liver and biliary constituents in cholestasis.
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Affiliation(s)
- R Müllenbach
- Maternal and Fetal Disease Group, 3rd Floor IRDB, Imperial College London, Hammersmith Campus, Du Cane Road, London W12 0NN, UK
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20
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Chu WCW, Lam WWM, Lee KH, Yeung DKW, Sihoe J, Yeung CK. Phosphorus-31 MR Spectroscopy in Pediatric Liver Transplant Recipients: A Noninvasive Assessment of Graft Status with Correlation with Liver Function Tests and Liver Biopsy. AJR Am J Roentgenol 2005; 184:1624-9. [PMID: 15855128 DOI: 10.2214/ajr.184.5.01841624] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Noninvasive in vivo hepatic phosphorus-31 MR spectroscopy has recently been shown to provide information about hepatic functional status. We sought to show the correlation of phosphorus-31 MR spectroscopy with blood biochemistry and liver biopsy results in pediatric patients after liver transplantation. MATERIALS AND METHODS Eleven pediatric transplant recipients (eight with good graft function, two with chronic hepatitis, and one with acute rejection) and four healthy control subjects were studied with in vivo 31P MR spectroscopy. Ratios of phosphomonoesters (PME) to total phosphorus (TP), phosphodiester (PDE) to TP, nucleotide triphosphates (NTP), inorganic phosphate (Pi), and intracellular acid-base status (pH) were measured. Liver function test (n = 11) and biopsy (n = 3) results were obtained for correlation with spectroscopic findings. RESULTS The eight patients with good graft function displayed spectral profiles similar to those of the healthy subjects, and no significant difference in the metabolic ratios of these patients compared with the control subjects was detected. Three patients with abnormal liver function and biopsy-proven hepatic complications showed elevated PME/TP ratios when compared with those of both the control subjects and the group with good graft function. CONCLUSION Phosphorus-31 MR spectroscopy is a feasible technique for the noninvasive assessment of host-related complications in pediatric patients after liver transplantation. Our preliminary data suggest that the technique may be integrated with MRI for the investigation of impaired liver function in transplant recipients when neither a biliary complication nor a vascular complication is identified.
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Affiliation(s)
- Winnie C W Chu
- Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Ngan Shing St., Shatin, Hong Kong SAR, China.
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Khan SA, Cox IJ, Hamilton G, Thomas HC, Taylor-Robinson SD. In vivo and in vitro nuclear magnetic resonance spectroscopy as a tool for investigating hepatobiliary disease: a review of H and P MRS applications. Liver Int 2005; 25:273-81. [PMID: 15780050 DOI: 10.1111/j.1478-3231.2005.01090.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a non-invasive technique, which allows the study of cellular biochemistry and metabolism. It is a diverse research tool, widely used by biochemists to investigate pathophysiological processes in vitro and, more recently, by physicians to determine disease abnormalities in vivo. This article reviews the basics of the NMR phenomenon and summarises previous research on the hepatobiliary system using both laboratory-based and clinical methodologies. The role of proton and phosphorus-31 ((31)P) NMR spectroscopy in the study of malignant and non-malignant liver disease and studies of bile composition are discussed. In vivo techniques (magnetic resonance spectroscopy, MRS) can be performed as an adjunct to standard MR examination of the liver. Although still primarily a research tool, the in vivo technique provides non-invasive biochemical information on disease severity and holds promise in its use to gauge response to treatment regimens.
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Affiliation(s)
- Shahid A Khan
- Liver Unit, Department of Medicine A, St Mary's Hospital Campus, Imperial College London, 10th Floor, QEQM Building, London W2 1NY, UK.
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Thomas EL, Hamilton G, Patel N, O'Dwyer R, Doré CJ, Goldin RD, Bell JD, Taylor-Robinson SD. Hepatic triglyceride content and its relation to body adiposity: a magnetic resonance imaging and proton magnetic resonance spectroscopy study. Gut 2005; 54:122-7. [PMID: 15591516 PMCID: PMC1774370 DOI: 10.1136/gut.2003.036566] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hepatic steatosis is associated with obesity and type II diabetes. Proton magnetic resonance spectroscopy (1H MRS) is a non-invasive method for measurement of tissue fat content, including intrahepatocellular lipids (IHCL) and intramyocellular lipids (IMCL). PATIENTS AND METHODS We used 1H MRS and whole body magnetic resonance imaging (MRI) to assess the relationship between IHCL accumulation, total body adipose tissue (AT) content/distribution, and IMCL content in 11 subjects with biopsy proven hepatic steatosis and 23 normal volunteers. RESULTS IHCL signals were detectable in all subjects but were significantly greater in hepatic steatosis (geometric mean (GM) 11.5 (interquartile range (IQR) 7.0-39.0)) than in normal volunteers (GM 2.7 (IQR 0.7-9.3); p=0.02). In the study group as a whole, IHCL levels were significantly greater in overweight compared with lean subjects (body mass index (BMI) >25 kg/m2 (n=23): GM 7.7 (IQR 4.0-28.6) v BMI <25 kg/m2 (n=11): GM 1.3 (IQR 0.3-3.6; p=0.004)). There was a significant association between IHCL content and indices of overall obesity (expressed as a percentage of body weight) for total body fat (p=0.001), total subcutaneous AT (p=0.007), and central obesity (subcutaneous abdominal AT (p=0.001) and intra-abdominal AT (p=0.001)), after allowing for sex and age. No correlation between IHCL content and IMCL was observed. A significant correlation was observed between serum alanine aminotransferase and liver fat content (r=0.57, p=0.006). CONCLUSIONS Our results suggest that hepatic steatosis appears to be closely related to body adiposity, especially central obesity. MRS may be a useful method for monitoring IHCL in future interventional studies.
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Affiliation(s)
- E L Thomas
- Robert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Hammersmith Hospital, Du Cane Rd, London W12 0HS, UK
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Corbin IR, Ryner LN, Singh H, Minuk GY. Quantitative hepatic phosphorus-31 magnetic resonance spectroscopy in compensated and decompensated cirrhosis. Am J Physiol Gastrointest Liver Physiol 2004; 287:G379-84. [PMID: 15191882 DOI: 10.1152/ajpgi.00418.2003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Few studies have examined the physiological/biochemical status of hepatocytes in patients with compensated and decompensated cirrhosis in situ. Phosphorus-31 magnetic resonance spectroscopy ((31)P MRS) is a noninvasive technique that permits direct assessments of tissue bioenergetics and phospholipid metabolism. Quantitative (31)P MRS was employed to document differences in the hepatic metabolite concentrations among patients with compensated and decompensated cirrhosis as well as healthy controls. All MRS examinations were performed on a 1.5-T General Electric Signa whole body scanner. The concentration of hepatic phosphorylated metabolites among patients with compensated cirrhosis (n = 7) was similar to that among healthy controls (n = 8). However, patients with decompensated cirrhosis (n = 6) had significantly lower levels of hepatic ATP compared with patients with compensated cirrhosis and healthy controls (P < 0.02 and P < 0.009, respectively) and a higher phosphomonoester/phosphodiester ratio than controls (P < 0.003). The results of this study indicate that metabolic disturbances in hepatic energy and phospholipid metabolism exist in patients with decompensated cirrhosis that are not present in patients with compensated cirrhosis or healthy controls. These findings provide new insights into the pathophysiology of hepatic decompensation.
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Affiliation(s)
- I R Corbin
- John Buhler Research Centre, 803F-715 McDermot Ave., Winnipeg, Manitoba, Canada.
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Lim AKP, Patel N, Hamilton G, Hajnal JV, Goldin RD, Taylor-Robinson SD. The relationship of in vivo 31P MR spectroscopy to histology in chronic hepatitis C. Hepatology 2003; 37:788-94. [PMID: 12668971 DOI: 10.1053/jhep.2003.50149] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Liver biopsy remains the gold standard for characterizing diffuse liver disease and is associated with significant morbidity and, rarely, mortality. Our aim was to investigate whether a noninvasive technique, in vivo phosphorus 31 ((31)P)-magnetic resonance spectroscopy (MRS), could be used to assess the severity of hepatitis C virus (HCV)-related liver disease. Fifteen healthy controls and 48 patients with biopsy-proven HCV-related liver disease were studied prospectively. Based on their histologic fibrosis (F) and necroinflammatory (NI) scores, patients were divided into mild hepatitis (F <or= 2/6, NI <or= 3/18), moderate/severe hepatitis (3 <or= F < 6 or NI >or= 4/18), and cirrhosis (F = 6/6). Hepatic (31)P MR spectra were obtained using a 1.5-T spectroscopy system. Quantitation of the (31)P signals was performed in the time domain using the Advanced MAgnetic RESonance algorithm. There was a monotonic increase in the mean +/- 1 standard error phosphomonoester (PME) to phosphodiester (PDE) ratios for the control, mild disease, moderate disease, and cirrhosis groups: 0.15 +/- 0.01, 0.18 +/- 0.02, 0.25 +/- 0.02, 0.38 +/- 0.04, respectively (ANOVA, P <.001). An 80% sensitivity and specificity was achieved when using a PME/PDE ratio less than or equal to 0.2 to denote mild hepatitis and a corresponding ratio greater than or equal to 0.3 to denote cirrhosis. No other significant spectral changes were observed. In conclusion, (31)P MRS can separate mild from moderate disease and these 2 groups from cirrhosis. The ability to differentiate these populations of patients has therapeutic implications and (31)P MRS, in some situations, would not only complement a liver biopsy but could replace it and be of particular value in assessing disease progression.
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Affiliation(s)
- Adrian K P Lim
- Robert Steiner MRI Unit, Medical Research Council Clinical Sciences Centre, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK.
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Corbin IR, Buist R, Peeling J, Zhang M, Uhanova J, Minuk GK. Utility of hepatic phosphorus-31 magnetic resonance spectroscopy in a rat model of acute liver failure. J Investig Med 2003; 51:42-9. [PMID: 12580320 DOI: 10.2310/6650.2003.33540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The ability to document the extent of hepatic injury and predict the outcome of fulminant hepatic failure would be helpful in identifying those patients who might benefit from liver transplantation. The aim of the present study was to determine whether in vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) accurately assesses the severity of liver damage and is of prognostic value in a D-galactosamine (D-galN)-induced model of acute liver failure. Adult male Sprague-Dawley rats (n = 36) received an intraperitoneal dose of D-galN (1.0 g/kg), and MRS examinations were performed at peak (48 hours) and in subsequent experiments, just prior to peak (30 hours) hepatic injury. Rats not exposed to D-galN served as controls. The concentration of hepatic phosphorylated metabolites decreased in proportion to the severity of liver injury at 48 hours. Significant correlations were detected between hepatic adenosine triphosphate (ATP) and serum aspartate aminotransferase, bilirubin, and percentage of hepatocyte necrosis identified histologically (r = -.91, -.74, and -.92, respectively; p < .001). Prior to peak hepatic injury (30 hours), 31P MRS was able to predict with 100% accuracy those rats that would survive (ATP > 2.3 mM) and those that would not (ATP < 1.5 mM). When an intermediate cutoff value of 2.0 mM was selected, ATP levels were able to correctly predict survival and death with 80% and 60% accuracy, respectively. These findings indicate that hepatic ATP levels as measured by 31P MRS provide a noninvasive indication of the severity of liver damage and serve as a useful prognostic indicator of outcome in this model of acute liver failure.
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Affiliation(s)
- Ian R Corbin
- Liver Diseases Unit, Department of Medicine, University of Manitoba, Winnipeg, MB
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Lim AKP, Hamilton G, Patel N, Bell JD, Taylor-Robinson SD. H MR spectroscopy in the evaluation of the severity of chronic liver disease. Radiology 2003; 226:288-9. [PMID: 12511705 DOI: 10.1148/radiol.2261020517] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Vejchapipat P, Proctor E, Ramsay A, Petros A, Gadian DG, Spitz L, Pierro A. Intestinal energy metabolism after ischemia-reperfusion: Effects of moderate hypothermia and perfluorocarbons. J Pediatr Surg 2002; 37:786-90. [PMID: 11987102 DOI: 10.1053/jpsu.2002.32288] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE This study investigated the roles of moderate hypothermia and extraluminal oxygenated perfluorcarbon (PFC) on intestinal metabolism after ischemia-reperfusion. METHODS A model of 30-minute intestinal ischemia followed by 60 minutes of reperfusion was used. The animals were maintained at either normothermia (36.5 to 37.5 degrees C) or moderate hypothermia (31 to 32 degrees C). Four groups of adult rats were studied (n = 8 per group): (A) sham at normothermia, (B) ischemia-reperfusion at normothermia, (C) ischemia-reperfusion at hypothermia and, (D) ischemia-reperfusion with extraluminal oxygenated PFC perfusion during ischemia at normothermia. Intestinal phosphocreatine, ATP and lactate levels were measured. Histologic changes in the intestine were evaluated. RESULTS Intestinal ischemia-reperfusion at normothermia caused a marked reduction in phosphocreatine and ATP with an increase in lactate. Moderate hypothermia exerted beneficial effects by attenuating the depletion of high-energy phosphates and the elevation of lactate. Extraluminal PFC perfusion during ischemia failed to produce a protective effect on high-energy phosphates, although it reduced lactate accumulation. Moderate hypothermia significantly decreased the degree of mucosal damage. CONCLUSIONS Whole-body moderate hypothermia protects the small intestine from reperfusion injury as measured both biochemically and histologically. Extraluminal oxygenated PFC administration during ischemia did not protect the intestine from reperfusion injury in this model.
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Mann DV, Lam WWM, Magnus Hjelm N, So NMC, Yeung DKW, Metreweli C, Lau WY. Biliary drainage for obstructive jaundice enhances hepatic energy status in humans: a 31-phosphorus magnetic resonance spectroscopy study. Gut 2002; 50:118-22. [PMID: 11772978 PMCID: PMC1773079 DOI: 10.1136/gut.50.1.118] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Biliary obstruction impairs liver function although the pathophysiological mechanism is incompletely understood. AIMS The aim of this study was to examine serial changes in liver metabolism in patients with obstructive jaundice using image guided in vivo 31-phosphorus magnetic resonance spectroscopy ((31)P MRS). This technique allows repeated and non-invasive assay of organ energy metabolism and phospholipid biochemistry. PATIENTS We studied 10 patients presenting with obstructive jaundice secondary to extrahepatic localised malignancy. There were eight men and two women, median age 72 years (range 54-94), six with cholangiocarcinoma (all Bismuth type 1) and four with carcinoma of the head of the pancreas. Ten healthy volunteers (median age 24 years (range 21-26)) were studied for comparison. METHODS Hepatic metabolism in jaundiced patients was measured by (31)P MRS at presentation and again after a one week period of biliary drainage. Conventional liver function tests were also recorded. RESULTS Compared with controls, liver spectra from jaundiced patients contained an excess of phosphomonoester (PME) metabolites (PME/total phosphate median 10.3% (interquartile range 8.7-11.5) in controls, 15.4% (13.1-17.7) in jaundiced cases; p<0.01). Biliary decompression was achieved in all patients (five with internal stents and five by external drainage catheters), and plasma biochemistry improved predictably (bilirubin 176 micromol/l (158-351) at presentation, 110 micromol/l (42-241) after drainage for one week; p<0.01). Enhancement of hepatic energy status, measured by the ratio of adenosine triphosphate (ATP) to inorganic phosphate (Pi), was observed in all cases after relief of biliary obstruction (ATP/Pi 1.4 (1.17-1.69) at presentation, 1.97 (1.4-2.48) after drainage; p<0.01) and was independent of the route of bile drainage. Hepatic phosphodiester (PDE) content was decreased after relief of obstruction (PDE/total phosphate 25.2% (20.5-27.4) at presentation, 19.8% (16.6-24.5) after drainage; p<0.01). This change was probably due to a reduction in the contribution from bile contents to this resonance as a strong PDE signal was also detectable in spectra obtained from separate bile specimens. CONCLUSIONS Obstructive jaundice produces alterations in liver phosphoester biochemistry, most likely reflecting disturbances in phospholipid metabolism. Relief of biliary obstruction is associated with a measurable increase in hepatic energy status. Bile may contribute to the phosphodiester signal of the 31-phosphorus liver spectrum and changes in these resonances must therefore be interpreted with caution and in relation to the clinical situation. Monitoring of liver metabolism by (31)P MRS may allow clinicians to refine the selection and timing of therapeutic options in jaundiced patients.
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Affiliation(s)
- D V Mann
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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Changani KK, Jalan R, Cox IJ, Ala-Korpela M, Bhakoo K, Taylor-Robinson SD, Bell JD. Evidence for altered hepatic gluconeogenesis in patients with cirrhosis using in vivo 31-phosphorus magnetic resonance spectroscopy. Gut 2001; 49:557-64. [PMID: 11559655 PMCID: PMC1728472 DOI: 10.1136/gut.49.4.557] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND AIMS Alterations in gluconeogenesis in the diseased liver can be assessed non-invasively using magnetic resonance spectroscopy by measuring changes in phosphomonoester resonance which contains information regarding several metabolites, including the phosphorylated intermediates of the gluconeogenic pathway. METHODS 31P magnetic resonance spectroscopy was used to determine changes in phosphomonoesters following bolus infusions of 2.8 mmol/kg L-alanine in five patients with functionally compensated cirrhosis and in five patients with functionally decompensated cirrhosis. RESULTS Compared with six healthy volunteers, baseline phosphomonoester values were elevated by 35% (p<0.05) in the compensated cirrhosis group and by 57% (p<0.01) in the decompensated cirrhosis group. Following alanine infusion, phosphomonoesters in healthy volunteers increased by 46% from baseline values (p<0.01), in patients with compensated cirrhosis by 27% (p<0.02) but those with decompensated cirrhosis showed no increase from baseline. There was a reduction in the percentage of inorganic phosphate signal in all subjects. CONCLUSIONS By analysing changes in phosphomonoester and inorganic phosphate resonances it is possible to discern clear metabolic differences between healthy volunteers and patients with cirrhosis of varying severity using magnetic resonance spectroscopy. Those patients with functionally decompensated cirrhosis have higher percentage baseline phosphomonoester values but the absence of phosphomonoester elevation following L-alanine infusion suggests that they are unable to mount a significant metabolic response with a progluconeogenic stimulus.
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Affiliation(s)
- K K Changani
- Magnetic Resonance Unit, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, UK
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Vejchapipat P, Williams SR, Proctor E, Lauro V, Spitz L, Pierro A. Moderate hypothermia ameliorates liver energy failure after intestinal ischaemia-reperfusion in anaesthetised rats. J Pediatr Surg 2001; 36:269-75. [PMID: 11172414 DOI: 10.1053/jpsu.2001.20687] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND/PURPOSE Intestinal ischaemia-reperfusion (IR) can cause liver failure. The aims of this work were to study the effects of intestinal IR on liver energy metabolism and to evaluate the effects of moderate hypothermia. METHODS Intestinal IR (90-minute intestinal ischaemia plus 60-minute or 240-minute reperfusion) was achieved by clamping and unclamping the superior mesenteric artery in rats. Normothermia or moderate hypothermia (30 degrees to 33 degrees C) was maintained by adjusting the environmental temperature. The ratio of hepatic inorganic phosphate to adenosine triphosphate (ATP) was monitored continuously during intestinal IR using in vivo phosphorus ((31)P) magnetic resonance spectroscopy. Phosphorus metabolites also were measured in extracts prepared from freeze-clamped liver and intestine. RESULTS Mortality occurred exclusively during normothermic intestinal IR. A progressive increase in the hepatic inorganic phosphate to ATP ratio after normothermic intestinal IR was observed. Moderate hypothermia delayed this effect. Analysis of liver extracts confirmed above findings. However, there was no difference in intestinal phosphocreatine or ATP between normothermic and hypothermic rats undergoing intestinal IR. CONCLUSIONS Intestinal IR at normothermia was associated with liver energy failure and high mortality rate. Moderate hypothermia ameliorated liver energy failure but did not attenuate intestinal energy failure after intestinal IR. Hypothermia may prove to be useful in the management of patients with intestinal IR injuries in the future.
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Affiliation(s)
- P Vejchapipat
- Surgery Unit and RCS Unit of Biophysics, Institute of Child Health and Great Ormond Street Hospital, London, England
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Beckmann N, Hof RP, Rudin M. The role of magnetic resonance imaging and spectroscopy in transplantation: from animal models to man. NMR IN BIOMEDICINE 2000; 13:329-348. [PMID: 11002313 DOI: 10.1002/1099-1492(200010)13:6<329::aid-nbm653>3.0.co;2-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Critical success factors in solid organ and vascular transplantation are the assessment of graft status/viability as well as stringent monitoring of transplant recipients, preferentially using noninvasive techniques. This review addresses the application of magnetic resonance imaging (MRI) and spectroscopy (MRS) in the field of transplantation. The first section is devoted to the description of the main MR techniques used for monitoring the status of the graft noninvasively. Subsequently, the role of MRI/MRS in the analysis of the viability of organs for transplantation is discussed. Since chronic rejection remains a major difficulty, development of new therapies is still ongoing. Thus, the third part is devoted to the use of MRI/MRS for monitoring graft rejection in animal models of transplantation. This is followed by a discussion of clinical studies of transplantation involving MRI/MRS. Finally, a general appraisal is made on available imaging techniques for the non-invasive characterization of grafts in situ, highlighting the role of MR methods in the field of transplantation.
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Affiliation(s)
- N Beckmann
- Core Technologies Area, Novartis Pharma AG, CH-4002 Basel, Switzerland.
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Abstract
PURPOSE This study explores the effects of ischemia-reperfusion on various metabolic aspects of the small intestine. METHODS Intestinal ischemia-reperfusion was obtained by clamping and unclamping the superior mesenteric artery in adult rats. Four groups of animals were studied: (A) sham operation for 150 minutes, (B) 90-minute intestinal ischemia, (C) 150-minute intestinal ischemia, and (D) 90-minute intestinal ischemia followed by 60-minute reperfusion. Body temperature was maintained at normothermia (36.5 to 37.5 degrees C). Concentrations of intestinal glucose, succinate, lactate, amino acids, phosphocholine (PC), glycerophosphocholine (GPC), choline, and phosphoenergetics were measured using magnetic resonance spectroscopy of freeze-clamped small intestine extracts. RESULTS Intestinal ischemia (groups B and C) alone caused a significant drop in glucose and phosphoenergetics but caused an increase in amino acids, succinate, and lactate. Ischemia and ischemia-reperfusion decreased PC and GPC but increased choline. After intestinal reperfusion (group D), no recovery of phosphoenergetics was observed, but there was partial recovery of glucose, succinate, lactate, and amino acids. CONCLUSIONS There is no recovery of phosphoenergetics after 90 minutes of intestinal ischemia followed by 60 minutes of reperfusion. Partial recovery of glucose, succinate, lactate, and amino acids may reflect equilibration of these metabolites between damaged cells and extracellular fluid.
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Affiliation(s)
- P Vejchapipat
- Surgery Unit, Institute of Child Health, London, England
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Taylor-Robinson SD, Buckley C, Changani KK, Hodgson HJ, Bell JD. Cerebral proton and phosphorus-31 magnetic resonance spectroscopy in patients with subclinical hepatic encephalopathy. LIVER 1999; 19:389-98. [PMID: 10533796 DOI: 10.1111/j.1478-3231.1999.tb00067.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND/AIMS In vivo magnetic resonance spectroscopy can be used to study cerebral metabolism non-invasively. We aimed to correlate 1H and 31P magnetic resonance spectral abnormalities in the brains of patients with subclinical hepatic encephalopathy. METHODS Eighteen patients were studied at 1.5T, with combined 1H and 31P magnetic resonance spectra obtained from multiple voxels in the cerebral cortex and basal ganglia. Peak area ratios of choline, glutamine/glutamate, relative to creatine in the 1H spectra and percentage phosphomonoesters, phosphodiesters and betaNTP signals relative to total 31P signals in the 31P spectra were measured. RESULTS Six patients did not complete the full examination - 31P results are available from 12 patients only. Relative to creatine, there were reductions in choline and elevations in glutamine/glutamate, varying across the brain with choline significantly reduced in occipital cortex (p<0.05) and glutamine/glutamate most significantly elevated in temporo-parietal cortex (p<0.0001). Percentage phosphomonoester (p<0.05), phosphodiester (p<0.05) and betaNTP (p<0.005) signals were significantly decreased in basal ganglia spectra. No correlation was found between the magnitude of 1H and 31P MRS changes, except between percentage phosphodiester decrease and glutamine/glutamate to creatine increase in occipital cortex. CONCLUSION The results of this study point to a multifactorial aetiology for this condition.
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Affiliation(s)
- S D Taylor-Robinson
- MRC Clinical Sciences Centre and Department of Medicine (Medicine A), Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
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