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Pfleger L, Gajdošík M, Wolf P, Smajis S, Fellinger P, Kuehne A, Krumpolec P, Trattnig S, Winhofer Y, Krebs M, Krššák M, Chmelík M. Absolute Quantification of Phosphor-Containing Metabolites in the Liver Using 31 P MRSI and Hepatic Lipid Volume Correction at 7T Suggests No Dependence on Body Mass Index or Age. J Magn Reson Imaging 2018; 49:597-607. [PMID: 30291654 PMCID: PMC6586048 DOI: 10.1002/jmri.26225] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 01/07/2023] Open
Abstract
Background Hepatic disorders are often associated with changes in the concentration of phosphorus‐31 (31P) metabolites. Absolute quantification offers a way to assess those metabolites directly but introduces obstacles, especially at higher field strengths (B0 ≥ 7T). Purpose To introduce a feasible method for in vivo absolute quantification of hepatic 31P metabolites and assess its clinical value by probing differences related to volunteers' age and body mass index (BMI). Study Type Prospective cohort. Subjects/Phantoms Four healthy volunteers included in the reproducibility study and 19 healthy subjects arranged into three subgroups according to BMI and age. Phantoms containing 31P solution for correction and validation. Field Strength/Sequence Phase‐encoded 3D pulse‐acquire chemical shift imaging for 31P and single‐volume 1H spectroscopy to assess the hepatocellular lipid content at 7T. Assessment A phantom replacement method was used. Spectra located in the liver with sufficient signal‐to‐noise ratio and no contamination from muscle tissue, were used to calculate following metabolite concentrations: adenosine triphosphates (γ‐ and α‐ATP); glycerophosphocholine (GPC); glycerophosphoethanolamine (GPE); inorganic phosphate (Pi); phosphocholine (PC); phosphoethanolamine (PE); uridine diphosphate‐glucose (UDPG); nicotinamide adenine dinucleotide‐phosphate (NADH); and phosphatidylcholine (PtdC). Correction for hepatic lipid volume fraction (HLVF) was performed. Statistical Tests Differences assessed by analysis of variance with Bonferroni correction for multiple comparison and with a Student's t‐test when appropriate. Results The concentrations for the young lean group corrected for HLVF were 2.56 ± 0.10 mM for γ‐ATP (mean ± standard deviation), α‐ATP: 2.42 ± 0.15 mM, GPC: 3.31 ± 0.27 mM, GPE: 3.38 ± 0.87 mM, Pi: 1.42 ± 0.20 mM, PC: 1.47 ± 0.24 mM, PE: 1.61 ± 0.20 mM, UDPG: 0.74 ± 0.17 mM, NADH: 1.21 ± 0.38 mM, and PtdC: 0.43 ± 0.10 mM. Differences found in ATP levels between lean and overweight volunteers vanished after HLVF correction. Data Conclusion Exploiting the excellent spectral resolution at 7T and using the phantom replacement method, we were able to quantify up to 10 31P‐containing hepatic metabolites. The combination of 31P magnetic resonance spectroscopy imaging data acquisition and HLVF correction was not able to show a possible dependence of 31P metabolite concentrations on BMI or age, in the small healthy population used in this study. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:597–607.
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Affiliation(s)
- Lorenz Pfleger
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Martin Gajdošík
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
- Medical University of Vienna, Department of Biomedical Imaging and Image‐guided Therapy, High Field MR CenterViennaAustria
| | - Peter Wolf
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Sabina Smajis
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Paul Fellinger
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Andre Kuehne
- MRI.TOOLS GmbHBerlinGermany
- Medical University of Vienna, Center for Medical Physics and Biomedical EngineeringViennaAustria
| | - Patrik Krumpolec
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
- Slovak Academy of Sciences, Biomedical Research Center, Institute of Experimental EndocrinologyBratislavaSlovakia
| | - Siegfried Trattnig
- Medical University of Vienna, Department of Biomedical Imaging and Image‐guided Therapy, High Field MR CenterViennaAustria
- Medical University of Vienna, Christian Doppler Laboratory for Clinical Molecular Imaging, MOLIMAViennaAustria
| | - Yvonne Winhofer
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Michael Krebs
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
| | - Martin Krššák
- Medical University of Vienna, Department of Internal Medicine III, Division of Endocrinology and MetabolismViennaAustria
- Medical University of Vienna, Department of Biomedical Imaging and Image‐guided Therapy, High Field MR CenterViennaAustria
- Medical University of Vienna, Christian Doppler Laboratory for Clinical Molecular Imaging, MOLIMAViennaAustria
| | - Marek Chmelík
- Medical University of Vienna, Department of Biomedical Imaging and Image‐guided Therapy, High Field MR CenterViennaAustria
- Medical University of Vienna, Christian Doppler Laboratory for Clinical Molecular Imaging, MOLIMAViennaAustria
- Karl Landsteiner Institute for Clinical Molecular MRViennaAustria
- University of PrešovFaculty of HealthcarePrešovSlovakia
- General Hospital of Levoča, Radiology DepartmentLevočaSlovakia
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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: 19] [Impact Index Per Article: 2.7] [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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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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Bashir A, Gropler R, Ackerman J. Absolute Quantification of Human Liver Phosphorus-Containing Metabolites In Vivo Using an Inhomogeneous Spoiling Magnetic Field Gradient. PLoS One 2015; 10:e0143239. [PMID: 26633549 PMCID: PMC4669158 DOI: 10.1371/journal.pone.0143239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/01/2015] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Absolute concentrations of high-energy phosphorus (31P) metabolites in liver provide more important insight into physiologic status of liver disease compared to resonance integral ratios. A simple method for measuring absolute concentrations of 31P metabolites in human liver is described. The approach uses surface spoiling inhomogeneous magnetic field gradient to select signal from liver tissue. The technique avoids issues caused by respiratory motion, chemical shift dispersion associated with linear magnetic field gradients, and increased tissue heat deposition due to radiofrequency absorption, especially at high field strength. METHODS A method to localize signal from liver was demonstrated using superficial and highly non-uniform magnetic field gradients, which eliminate signal(s) from surface tissue(s) located between the liver and RF coil. A double standard method was implemented to determine absolute 31P metabolite concentrations in vivo. 8 healthy individuals were examined in a 3 T MR scanner. RESULTS Concentrations of metabolites measured in eight healthy individuals are: γ-adenosine triphosphate (ATP) = 2.44 ± 0.21 (mean ± sd) mmol/l of wet tissue volume, α-ATP = 3.2 ± 0.63 mmol/l, β-ATP = 2.98 ± 0.45 mmol/l, inorganic phosphates (Pi) = 1.87 ± 0.25 mmol/l, phosphodiesters (PDE) = 10.62 ± 2.20 mmol/l and phosphomonoesters (PME) = 2.12 ± 0.51 mmol/l. All are in good agreement with literature values. CONCLUSIONS The technique offers robust and fast means to localize signal from liver tissue, allows absolute metabolite concentration determination, and avoids problems associated with constant field gradient (linear field variation) localization methods.
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Affiliation(s)
- Adil Bashir
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Robert Gropler
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Joseph Ackerman
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Chemistry, Washington University, St. Louis, Missouri, United States of America
- * E-mail:
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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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Laufs A, Livingstone R, Nowotny B, Nowotny P, Wickrath F, Giani G, Bunke J, Roden M, Hwang JH. Quantitative liver 31
P magnetic resonance spectroscopy at 3T on a clinical scanner. Magn Reson Med 2013; 71:1670-5. [DOI: 10.1002/mrm.24835] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 05/10/2013] [Accepted: 05/10/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Alessandra Laufs
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
| | - Roshan Livingstone
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
| | - Bettina Nowotny
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
| | - Peter Nowotny
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
| | - Frithjof Wickrath
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
| | - Guido Giani
- Institute for Biometry and Epidemiology; German Diabetes Center; Düsseldorf Germany
| | - Jürgen Bunke
- Clinical Science, Philips Healthcare; Hamburg Germany
| | - Michael Roden
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
- Department of Metabolic Diseases; University Clinics, Heinrich-Heine University; Düsseldorf Germany
| | - Jong-Hee Hwang
- Institute of Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
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Panda A, Jones S, Stark H, Raghavan RS, Sandrasegaran K, Bansal N, Dydak U. Phosphorus liver MRSI at 3 T using a novel dual-tuned eight-channel ³¹P/¹H H coil. Magn Reson Med 2012; 68:1346-56. [PMID: 22287206 DOI: 10.1002/mrm.24164] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 12/11/2022]
Abstract
Although phosphorus-31 (³¹P) magnetic resonance spectroscopy holds potential as noninvasive tool to monitor treatment response of liver malignancies, the lack of appropriate coils has so far restricted its use to liver lesions close to the surface. A novel eight-channel phased-array dual-tuned ³¹P/¹H coil that can assess ³¹P metabolism in deeper liver tissue as well is presented in this article. Analysis of its performance demonstrates that this coil can provide good sensitivity across a width of 20 cm, thereby enabling magnetic resonance spectroscopic imaging (MRSI) scans that can fully cover axial views of the abdomen in lean subjects. In vivo results and reproducibility of ³¹P MRSI at 3 T of axial slices covering the full depth of the liver are shown in healthy volunteers. To minimize intrasubject and intersubject data variability, spectra are corrected for coil sensitivities. Methods to maximize the reproducibility of coil placement and spectroscopic planning are discussed. The phosphomonoesters/phosphodiesters ratio calculated in healthy volunteers has an average intrasubject variation of 23% averaged over voxels selected from the entire liver. Finally, the feasibility of using the coil in the clinic is shown by preliminary ³¹P liver MRSI data obtained from a patient with hepatocellular carcinoma.
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Affiliation(s)
- Anshuman Panda
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
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Sijens PE. Parametric exploration of the liver by magnetic resonance methods. Eur Radiol 2009; 19:2594-607. [PMID: 19504103 PMCID: PMC2762052 DOI: 10.1007/s00330-009-1470-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 04/24/2009] [Accepted: 04/30/2009] [Indexed: 12/16/2022]
Abstract
MRI, as a completely noninvasive technique, can provide quantitative assessment of perfusion, diffusion, viscoelasticity and metabolism, yielding diverse information about liver function. Furthermore, pathological accumulations of iron and lipids can be quantified. Perfusion MRI with various contrast agents is commonly used for the detection and characterization of focal liver disease and the quantification of blood flow parameters. An extended new application is the evaluation of the therapeutic effect of antiangiogenic drugs on liver tumours. Novel, but already widespread, is a histologically validated relaxometry method using five gradient echo sequences for quantifying liver iron content elevation, a measure of inflammation, liver disease and cancer. Because of the high perfusion fraction in the liver, the apparent diffusion coefficients strongly depend on the gradient factors used in diffusion-weighted MRI. While complicating analysis, this offers the opportunity to study perfusion without contrast injection. Another novel method, MR elastography, has already been established as the only technique able to stage fibrosis or diagnose mild disease. Liver fat content is accurately determined with multivoxel MR spectroscopy (MRS) or by faster MRI methods that are, despite their widespread use, prone to systematic error. Focal liver disease characterisation will be of great benefit once multivoxel methods with fat suppression are implemented in proton MRS, in particular on high-field MR systems providing gains in signal-to-noise ratio and spectral resolution.
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Affiliation(s)
- Paul E Sijens
- Radiology, University Medical Center Groningen and University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
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Szendroedi J, Chmelik M, Schmid AI, Nowotny P, Brehm A, Krssak M, Moser E, Roden M. Abnormal hepatic energy homeostasis in type 2 diabetes. Hepatology 2009; 50:1079-86. [PMID: 19637187 DOI: 10.1002/hep.23093] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
UNLABELLED Increased hepatocellular lipids relate to insulin resistance and are typical for individuals with type 2 diabetes mellitus (T2DM). Steatosis and T2DM have been further associated with impaired muscular adenosine triphosphate (ATP) turnover indicating reduced mitochondrial fitness. Thus, we tested the hypothesis that hepatic energy metabolism could be impaired even in metabolically well-controlled T2DM. We measured hepatic lipid volume fraction (HLVF) and absolute concentrations of gammaATP, inorganic phosphate (Pi), phosphomonoesters and phosphodiesters using noninvasive (1)H/ (31)P magnetic resonance spectroscopy in individuals with T2DM (58 +/- 6 years, 27 +/- 3 kg/m (2)), and age-matched and body mass index-matched (mCON; 61 +/- 4 years, 26 +/- 4 kg/m (2)) and young lean humans (yCON; 25 +/- 3 years, 22 +/- 2 kg/m (2), P < 0.005, P < 0.05 versus T2DM and mCON). Insulin-mediated whole-body glucose disposal (M) and endogenous glucose production (iEGP) were assessed during euglycemic-hyperinsulinemic clamps. Individuals with T2DM had 26% and 23% lower gammaATP (1.68 +/- 0.11; 2.26 +/- 0.20; 2.20 +/- 0.09 mmol/L; P < 0.05) than mCON and yCON individuals, respectively. Further, they had 28% and 31% lower Pi than did individuals from the mCON and yCON groups (0.96 +/- 0.06; 1.33 +/- 0.13; 1.41 +/- 0.07 mmol/L; P < 0.05). Phosphomonoesters, phosphodiesters, and liver aminotransferases did not differ between groups. HLVF was not different between those from the T2DM and mCON groups, but higher (P = 0.002) than in those from the yCON group. T2DM had 13-fold higher iEGP than mCON (P < 0.05). Even after adjustment for HLVF, hepatic ATP and Pi related negatively to hepatic insulin sensitivity (iEGP) (r =-0.665, P = 0.010, r =-0.680, P = 0.007) but not to whole-body insulin sensitivity. CONCLUSION These data suggest that impaired hepatic energy metabolism and insulin resistance could precede the development of steatosis in individuals with T2DM.
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Affiliation(s)
- Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Germany
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Yu RS, Hao L, Dong F, Mao JS, Sun JZ, Chen Y, Lin M, Wang ZK, Ding WH. Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits. World J Gastroenterol 2009; 15:2723-30. [PMID: 19522022 PMCID: PMC2695887 DOI: 10.3748/wjg.15.2723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy (31P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of 31P MRS in acute hepatic radiation injury.
METHODS: A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models. Blood biochemical tests, 31P MRS and pathological examinations were carried out 24 h after irradiation. The degree of injury was evaluated according to LDS and pathology. Ten healthy rabbits served as controls. The MR examination was performed on a 1.5 T imager using a 1H/31P surface coil by the 2D chemical shift imaging technique. The relative quantities of phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. The data were statistically analyzed.
RESULTS: (1) Relative quantification of phosphorus metabolites: (a) ATP: there were significant differences (P < 0.05) (LDS-groups: control group vs mild group vs moderate group vs severe group, 1.83 ± 0.33 vs 1.55 ± 0.24 vs 1.27 ± 0.09 vs 0.98 ± 0.18; pathological groups: control group vs mild group vs moderate group vs severe group, 1.83 ± 0.33 vs 1.58 ± 0.25 vs 1.32 ± 0.07 vs 1.02 ± 0.18) of ATP relative quantification among control group, mild injured group, moderate injured group, and severe injured group according to both LDS grading and pathological grading, respectively, and it decreased progressively with the increased degree of injury (r = -0.723, P = 0.000). (b) PME and Pi; the relative quantification of PME and Pi decreased significantly in the severe injured group, and the difference between the control group and severe injured group was significant (P < 0.05) (PME: LDS-control group vs LDS-severe group, 0.86 ± 0.23 vs 0.58 ± 0.22, P = 0.031; pathological control group vs pathological severe group, 0.86 ± 0.23 vs 0.60 ± 0.21, P = 0.037; Pi: LDS-control group vs LDS-severe group, 0.74 ± 0.18 vs 0.43 ± 0.14, P = 0.013; pathological control group vs pathological severe group, 0.74 ± 0.18 vs 0.43 ± 0.14, P = 0.005) according to LDS grading and pathological grading, respectively. (c) PDE; there were no significant differences among groups according to LDS grading, and no significant differences between the control group and experimental groups according to pathological grading. (2) The ratio of relative quantification of phosphorus metabolites: significant differences (P < 0.05) (LDS-moderate group and LDS-severe group vs LDS-control group and LDS-mild group, 1.94 ± 0.50 and 1.96 ± 0.72 vs 1.43 ± 0.31 and 1.40 ± 0.38) were only found in PDE/ATP between the moderate injured group, the severe injured group and the control group, the mild injured group. No significant difference was found in other ratios of relative quantification of phosphorus metabolites.
CONCLUSION: 31P MRS is a useful method to evaluate early acute hepatic radiation injury. The relative quantification of hepatic ATP levels, which can reflect the pathological severity of acute hepatic radiation injury, is correlated with LDS.
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Chmelík M, Schmid AI, Gruber S, Szendroedi J, Krššák M, Trattnig S, Moser E, Roden M. Three-dimensional high-resolution magnetic resonance spectroscopic imaging for absolute quantification of31P metabolites in human liver. Magn Reson Med 2008; 60:796-802. [DOI: 10.1002/mrm.21762] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Solga SF, Horska A, Hemker S, Crawford S, Diggs C, Diehl AM, Brancati FL, Clark JM. Hepatic fat and adenosine triphosphate measurement in overweight and obese adults using 1H and 31P magnetic resonance spectroscopy. Liver Int 2008; 28:675-81. [PMID: 18331237 PMCID: PMC3096527 DOI: 10.1111/j.1478-3231.2008.01705.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND/AIMS Magnetic resonance spectroscopy (MRS) measures hepatic fat and adenosine triphosphate (ATP), but magnetic resonance studies are challenging in obese subjects. We aimed to evaluate the inter- and intrarater reliability and stability of hepatic fat and ATP measurements in a cohort of overweight and obese adults. METHODS We measured hepatic fat and ATP using proton MRS ((1)H MRS) and phosphorus MRS ((31)P MRS) at baseline in adults enrolled in the Action for Health in Diabetes (Look AHEAD) clinical trial at one site. Using logistic regression, we determined factors associated with successful MRS data acquisition. We calculated the intra- and inter-rater reliability for hepatic fat and ATP based on 20 scans analysed twice by two readers. We also calculated the stability of these measures three times on five healthy volunteers. RESULTS Of 244 participants recruited into our ancillary study, 185 agreed to MRS. We obtained usable hepatic fat data from 151 (82%) and ATP data from 105 (58%). Obesity was the strongest predictor of failed data acquisition; every unit increase in the body mass index reduced the likelihood of successful fat data by 11% and ATP data by 14%. The inter- and intrarater reliability were excellent for fat (intraclass correlation coefficient=0.99), but substantially more variable for ATP. Fat measures appeared relatively stable, but this was less true for ATP. CONCLUSIONS Obesity can hinder (1)H and (31)P MRS data acquisition and subsequent analysis. This impact was greater for hepatic ATP than hepatic fat.
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Affiliation(s)
- Steven F. Solga
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University, Baltimore, MD, USA
| | - Alena Horska
- Russel H. Morgan Department of Radiology and Radiologic Science, Johns Hopkins University, Baltimore, MD, USA
| | - Susanne Hemker
- Russel H. Morgan Department of Radiology and Radiologic Science, Johns Hopkins University, Baltimore, MD, USA
| | - Stephen Crawford
- Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
| | - Charalett Diggs
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University, Baltimore, MD, USA
| | - Anna Mae Diehl
- Department of Medicine, Duke University, Durham, NC, USA
| | - Frederick L. Brancati
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University, Baltimore, MD, USA,Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
| | - Jeanne M. Clark
- Department of Medicine, Division of Gastroenterology, Johns Hopkins University, Baltimore, MD, USA,Department of Epidemiology, Johns Hopkins University, Baltimore, MD, USA
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13
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Noren B, Dahlqvist O, Lundberg P, Almer S, Kechagias S, Ekstedt M, Franzén L, Wirell S, Smedby O. Separation of advanced from mild fibrosis in diffuse liver disease using 31P magnetic resonance spectroscopy. Eur J Radiol 2007; 66:313-20. [PMID: 17646074 DOI: 10.1016/j.ejrad.2007.06.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 05/08/2007] [Accepted: 06/04/2007] [Indexed: 12/12/2022]
Abstract
31P-MRS using DRESS was used to compare absolute liver metabolite concentrations (PME, Pi, PDE, gammaATP, alphaATP, betaATP) in two distinct groups of patients with chronic diffuse liver disorders, one group with steatosis (NAFLD) and none to moderate inflammation (n=13), and one group with severe fibrosis or cirrhosis (n=16). All patients underwent liver biopsy and extensive biochemical evaluation. A control group (n=13) was also included. Absolute concentrations and the anabolic charge, AC=[PME]/([PME]+[PDE]), were calculated. Comparing the control and cirrhosis groups, lower concentrations of PDE (p=0.025) and a higher AC (p<0.001) were found in the cirrhosis group. Also compared to the NAFLD group, the cirrhosis group had lower concentrations of PDE (p=0.01) and a higher AC (p=0.009). No significant differences were found between the control and NAFLD group. When the MRS findings were related to the fibrosis stage obtained at biopsy, there were significant differences in PDE between stage F0-1 and stage F4 and in AC between stage F0-1 and stage F2-3. Using a PDE concentration of 10.5mM as a cut-off value to discriminate between mild, F0-2, and advanced, F3-4, fibrosis the sensitivity and specificity were 81% and 69%, respectively. An AC cut-off value of 0.27 showed a sensitivity of 93% and a specificity of 54%. In conclusion, the results suggest that PDE is a marker of liver fibrosis, and that AC is a potentially clinically useful parameter in discriminating mild fibrosis from advanced.
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Affiliation(s)
- Bengt Noren
- Department of Radiology, Linköping University, SE-581 85 Linköping, Sweden
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14
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Sijens PE, Smit GP, Borgdorff MAJ, Kappert P, Oudkerk M. Multiple voxel 1H MR spectroscopy of phosphorylase-b kinase deficient patients (GSD IXa) showing an accumulation of fat in the liver that resolves with aging. J Hepatol 2006; 45:851-5. [PMID: 17005290 DOI: 10.1016/j.jhep.2006.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 06/06/2006] [Accepted: 06/28/2006] [Indexed: 01/19/2023]
Abstract
BACKGROUND/AIMS Phosphorylase-b deficient patients suffer from glycogen storage disease (GSD IXa) leading to liver enlargement which usually resolves during puberty and adolescence. This pathology has not yet been documented by (1)H MR spectroscopy (MRS) investigation. METHODS MRS of eight GSD IXa patients was performed in this study to assess whether or not liver fat content is elevated in GSD IXa and decreases with aging. An improvement in our MRS method compared with previous liver fat MRS studies is that we measured a plane of liver voxels at once rather than a single MRS voxel, yielding a reliable determination of liver fat content. RESULTS Fat contents of 3.4-10% were observed in young GSD IXa patients, as compared with 0.5-0.9% in controls, these dropped to control levels in patients past age 40 (r = -0.82; P < 0.01). CONCLUSIONS Liver fat content is increased in glycogen storage disease (GSD IXa) and normalizes with ageing. Assessing liver fat levels in this population is a novel and interesting concept. This could potentially enhance the understanding of liver function in that 20% of the population who has increased liver fat.
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Affiliation(s)
- Paul E Sijens
- Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, The Netherlands.
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Dezortova M, Taimr P, Skoch A, Spicak J, Hajek M. Etiology and functional status of liver cirrhosis by 31P MR spectroscopy. World J Gastroenterol 2006; 11:6926-31. [PMID: 16437594 PMCID: PMC4717032 DOI: 10.3748/wjg.v11.i44.6926] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To assess the functional status and etiology of liver cirrhosis by quantitative (31)P magnetic resonance spectroscopy (MRS). METHODS A total of 80 patients with liver cirrhosis of different etiology and functional status described by Child-Pugh score were examined and compared to 11 healthy volunteers. MR examination was performed on a 1.5 T imager using a (1)H/(31)P surface coil by the 2D chemical shift imaging technique. Absolute concentrations of phosphomonoesters (PME), phosphodiesters (PDE), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. RESULTS MRS changes reflected the degree of liver dysfunction in all the patients as well as in individual etiological groups. The most important change was a decrease of PDE. It was possible to distinguish alcoholic, viral and cholestatic etiologies based on MR spectra. Alcoholic and viral etiology differed in PDE (alcoholic, viral, controls: 6.5+/-2.3, 6.5+/-3.1, 10.8+/-2.7 mmol/L, P<0.001) and ATP (alcoholic, viral, controls: 2.9+/-0.8, 2.8+/-0.9, 3.7+/-1.0 mmol/L, P<0.01) from the control group. Unlike viral etiology, patients with alcoholic etiology also differed in Pi (alcoholic, controls: 1.2+/-0.4, 1.6+/-0.6 mmol/L, P<0.05) from controls. No significant changes were found in patients with cholestatic disease and controls; nevertheless, this group differed from both alcoholic and viral groups (cholestatic, alcoholic, viral: 9.4+/-2.7, 6.5+/-2.3, 6.5+/-3.1 mmol/L, P<0.005) in PDE. CONCLUSION (31)P MRS can significantly help in non-invasive separation of different etiological groups leading to liver cirrhosis. In addition, MRS changes reflect functional liver injury.
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Affiliation(s)
- Monika Dezortova
- MR-Unit, Department of Diagnostic and Interventional Radiology; Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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16
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Hamilton G, Allsop JM, Patel N, Forton DM, Thomas HC, O'Sullivan CPA, Hajnal JV, Taylor-Robinson SD. Variations due to analysis technique in intracellular pH measurements in simulated and in vivo31P MR spectra of the human brain. J Magn Reson Imaging 2006; 23:459-64. [PMID: 16506142 DOI: 10.1002/jmri.20524] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To investigate variation in pH generated by different analysis techniques and to find the most robust method, 31P MR brain spectra were acquired in vivo. Three different methods were used to measure the chemical shift of inorganic phosphate (Pi) relative to phosphocreatine (PCr). MATERIALS AND METHODS Eight healthy volunteers were scanned four times, and manual measurement of the chemical shift in a frequency domain spectrum using the manufacturer's software was compared with values produced by a frequency-domain analysis method (NMR1) and a prior-knowledge-based time-domain technique (MRUI). To explain the in vivo data, simulations of brain spectra, modified in ways typical of real variations in vivo, were produced and the pH was measured using manual measurement and MRUI. RESULTS Different measurement techniques produced systematically different pH values, with manual measurement producing the lowest variability (manual measurement: pH = 6.999, CoV = 0.297; NMR1: pH = 7.042, CoV = 0.501; MRUI: pH = 7.036, CoV = 0.606). While MRUI more accurately measured the pH of unaltered simulations, it was systematically affected by altering the simulated spectra. Manual measurement was unaffected. CONCLUSION Manual measurement produces the most consistent pH value, and there is no benefit in using more complex automated spectral fitting methods to measure the pH.
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Affiliation(s)
- Gavin Hamilton
- Robert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College London, London, United Kingdom.
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17
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Abstract
Hepatic phosphorus magnetic resonance spectroscopy (31P MRS) offers the exciting potential of studying metabolic processes in the human liver in vivo. Many investigators have utilized 31P MRS to research a broad range of metabolic questions, and there is outstanding potential for this imaging modality in the future. However, at times it is difficult to appreciate this potential because most published series have been small, and comparisons between studies are difficult. Indeed, the published literature contains significant variation in data acquisition and data analysis techniques and, perhaps most importantly, the interpretation of the data itself. As MR technology continues to evolve and more studies are being performed, perhaps a greater consensus of study techniques and endpoints will emerge. This review summarizes the present literature on human hepatic 31P MRS.
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Affiliation(s)
- Steven F Solga
- Division of Gastroenterology, Johns Hopkins University, Baltimore, MD 21205, USA.
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18
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Norén B, Lundberg P, Ressner M, Wirell S, Almer S, Smedby O. Absolute quantification of human liver metabolite concentrations by localized in vivo 31P NMR spectroscopy in diffuse liver disease. Eur Radiol 2004; 15:148-57. [PMID: 15351899 DOI: 10.1007/s00330-004-2434-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 06/04/2004] [Accepted: 06/28/2004] [Indexed: 12/13/2022]
Abstract
Phosphorus-31 NMR spectroscopy using slice selection (DRESS) was used to investigate the absolute concentrations of metabolites in the human liver. Absolute concentrations provide more specific biochemical information compared to spectrum integral ratios. Nine patients with histopathologically proven diffuse liver disease and 12 healthy individuals were examined in a 1.5-T MR scanner (GE Signa LX Echospeed plus). The metabolite concentration quantification procedures included: (1) determination of optimal depth for the in vivo measurements, (2) mapping the detection coil characteristics, (3) calculation of selected slice and liver volume ratios using simple segmentation procedures and (4) spectral analysis in the time domain. The patients had significantly lower concentrations of phosphodiesters (PDE), 6.3+/-3.9 mM, and ATP-beta, 3.6+/-1.1 mM, (P<0.05) compared with the control group (10.0+/-4.2 mM and 4.2+/-0.3 mM, respectively). The concentrations of phosphomonoesters (PME) were higher in the patient group, although this was not significant. Constructing an anabolic charge (AC) based on absolute concentrations, [PME]/([PME] + [PDE]), the patients had a significantly larger AC than the control subjects, 0.29 vs. 0.16 (P<0.005). Absolute concentration measurements of phosphorus metabolites in the liver are feasible using a slice selective sequence, and the technique demonstrates significant differences between patients and healthy subjects.
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Affiliation(s)
- Bengt Norén
- Depatment of Radiology/IMV, Linköping University, 581-85 Linköping, Sweden
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Hamilton G, Patel N, Forton DM, Hajnal JV, Taylor-Robinson SD. Prior knowledge for time domain quantification of in vivo brain or liver 31P MR spectra. NMR IN BIOMEDICINE 2003; 16:168-176. [PMID: 12884361 DOI: 10.1002/nbm.821] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Prior knowledge is required when quantifying in vivo (31)P magnetic resonance spectra from the brain or liver. The prior knowledge system we have used models both the phosphomonoester and phosphodiester resonances as two peaks of equal linewidth and fixed relative chemical shift. The analysis of the data is carried out in the time domain, which allows the broad component of the spectra to be modelled. This prior knowledge method has been tested for analysis of in vivo (31)P MR spectra from the liver and brain and gives results consistent with other methods that are also used to analyse the spectra, but with reduced variability. This technique may be utilized for studies requiring serial MR spectroscopy examinations, before and after patient treatment.
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Affiliation(s)
- Gavin Hamilton
- Robert Steiner MR Unit, Imaging Sciences Department, MRC Clinical Sciences Centre Imperial College London, London, UK.
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20
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Leij-Halfwerk S, Agteresch HJ, Sijens PE, Dagnelie PC. Adenosine triphosphate infusion increases liver energy status in advanced lung cancer patients: an in vivo 31P magnetic resonance spectroscopy study. Hepatology 2002; 35:421-4. [PMID: 11826418 DOI: 10.1053/jhep.2002.31318] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
We recently observed inhibition of weight loss in patients with advanced nonsmall-cell lung cancer after intravenous infusion of ATP. Because liver ATP levels were found to be decreased in lung cancer patients with weight loss, the present 31P magnetic resonance spectroscopy (MRS) study was aimed at investigating whether ATP infusion restores liver energy status in these patients. Nine patients with advanced nonsmall-cell lung cancer (stage IIIB/IV) were studied 1 week before (baseline) and at 22 to 24 hours of continuous ATP infusion (37-75 microg/kg/min). Localized hepatic 31P MR spectra (repetition time 15 seconds), obtained in the overnight-fasted state, were analyzed for ATP and P(i) content. Ten healthy subjects (without ATP infusion) served as control. Liver ATP levels in lung cancer patients increased from 8.8 +/- 0.7% (relative to total MR-detectable phosphate; mean +/- SE) at baseline to 12.2 +/- 0.9% during ATP infusion (P <.05), i.e., a level similar to that in healthy subjects (11.9 +/- 0.9%). The increase in ATP level during ATP infusion was most prominent in patients with > or = 5% weight loss (baseline: 7.9 +/- 0.7%, during ATP infusion: 12.8 +/- 1.0%, P < 0.01). In conclusion, ATP infusion restores hepatic energy levels in patients with advanced lung cancer, especially in weight-losing patients. These changes may contribute to the previously reported beneficial effects of ATP infusion on the nutritional status of lung cancer patients.
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Affiliation(s)
- Susanne Leij-Halfwerk
- Institute of Internal Medicine II, Erasmus University Medical Center Rotterdam, The Netherlands
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21
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Tosner Z, Dezortová M, Tintĕra J, Hájek M. Application of two-dimensional CSI for absolute quantification of phosphorus metabolites in the human liver. MAGMA (NEW YORK, N.Y.) 2001; 13:40-6. [PMID: 11410395 DOI: 10.1007/bf02668649] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
There have recently been a number of studies dealing with the absolute quantification of concentrations of MR-visible phosphorus compounds in different tissues. The use of absolute values rather than intensity ratios may furnish additional information about metabolic changes associated with different diseases. The purpose of this study was to develop a general procedure for measuring molar metabolite concentrations and to apply it with respect to the evaluation of human liver 31P-MRS data measured using a standard slice-selective two-dimensional CSI sequence and commercial 1H/31P surface coil. The experimental determination of all surface coil-related factors influencing signal intensity was undertaken using a gradient echo imaging technique that can be adapted to commercial systems. The resulting values for healthy volunteers (N = 9) showed concentrations of PME = 2.8 +/- 1.3 mM, PDE = 9.9 +/- 2.7 mM, P(i) = 1.7+/-0.7 mM, and ATP = 3.6 +/- 0.9 mM in the human liver. The data are quite consistent with published findings.
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Affiliation(s)
- Z Tosner
- MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Vídenská 1958/9, 140 21 4, Prague, Czech Republic
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22
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Leij-Halfwerk S, Dagneli PC, Kappert P, Oudkerk M, Sijens PE. Decreased energy and phosphorylation status in the liver of lung cancer patients with weight loss. J Hepatol 2000; 32:887-92. [PMID: 10898308 DOI: 10.1016/s0168-8278(00)80092-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
BACKGROUND/AIMS Altered energy status has been reported in the liver of tumour-bearing animals, but data on energy status in humans are scarce. Therefore, bioenergetics in tumour-free liver of lung cancer patients were monitored using 31P magnetic resonance spectroscopy (MRS) with infusion of L-alanine as a gluconeogenic challenge. METHODS Twenty-one overnight-fasted lung cancer patients without liver metastases, with (CaWL) or without weight loss (CaWS), and 12 healthy control subjects (C) were studied. Hepatic energy status was monitored before and during an i.v. L-alanine infusion of 1.4-2.8 mmol/kg + 2.8 mmol x kg(-1) x h(-1) for 90 min by 31p MR spectroscopy. RESULTS Baseline levels of ATP in WL lung cancer patients, expressed relative to total MR-detectable phosphate, were reduced (CaWL, 9.5+/-0.9% vs. CaWS, 12.6+/-0.8% and C, 12.4+/-0.8%; p<0.05) and inversely correlated with the degree of weight loss in lung cancer patients (r=-0.46, p=0.03). Pi/ATP ratios were increased (p<0.05), indicating reduced liver phosphorylation status. During L-alanine infusion, ATP levels decreased in all groups (p<0.05); in CaWL, ATP levels were lower at all time-points between 0-90 min as compared to both CaWS and C (p<0.05). Pi/ATP ratios were significantly higher after 70-90 min of L-alanine infusion in CaWL compared to CaWS and C (p<0.05). CONCLUSIONS Hepatic ATP and phosphorylation status are reduced in WL lung cancer patients, in contrast to WS patients and healthy subjects, and continue to decrease during infusion of a gluconeogenic substrate, suggesting impaired energy regenerating capacity in these patients.
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Affiliation(s)
- S Leij-Halfwerk
- Institute of Internal Medicine II, Department of Diagnostic Radiology, University Hospital Rotterdam, The Netherlands
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Abstract
Magnetic resonance imaging (MRI) is a well known diagnostic tool in radiology that produces unsurpassed images of the human body, in particular of soft tissue. However, the medical community is often not aware that MRI is an important yet limited segment of magnetic resonance (MR) or nuclear magnetic resonance (NMR) as this method is called in basic science. The tremendous morphological information of MR images sometimes conceal the fact that MR signals in general contain much more information, especially on processes on the molecular level. NMR is successfully used in physics, chemistry, and biology to explore and characterize chemical reactions, molecular conformations, biochemical pathways, solid state material, and many other applications that elucidate invisible characteristics of matter and tissue. In medical applications, knowledge of the molecular background of MRI and in particular MR spectroscopy (MRS) is an inevitable basis to understand molecular phenomenon leading to macroscopic effects visible in diagnostic images or spectra. This review shall provide the necessary background to comprehend molecular aspects of magnetic resonance applications in medicine. An introduction into the physical basics aims at an understanding of some of the molecular mechanisms without extended mathematical treatment. The MR typical terminology is explained such that reading of original MR publications could be facilitated for non-MR experts. Applications in MRI and MRS are intended to illustrate the consequences of molecular effects on images and spectra.
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Affiliation(s)
- C Boesch
- Department of Clinical Research, University of Bern, Switzerland
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