Dataset Information

Phosphodiester content measured in human liver by in vivo ³¹ P MR spectroscopy at 7 tesla.

ABSTRACT:

Purpose

Phosphorus (³¹ P) metabolites are emerging liver disease biomarkers. Of particular interest are phosphomonoester and phosphodiester (PDE) "peaks" that comprise multiple overlapping resonances in ³¹ P 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 T₁ s. Ten volunteers and 11 patients with liver cirrhosis were scanned at 7T. Liver spectra were acquired in 28?min using a 16-channel ³¹ P array and 3D chemical shift imaging. Concentrations were calculated using ?-adenosine-triphosphate (?-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: ?-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?ConclusionWe report human in vivo hepatic T₁ s 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.

SUBMITTER: Purvis LAB

PROVIDER: S-EPMC5697655 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature

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Phosphodiester content measured in human liver by in vivo <sup>31</sup> P MR spectroscopy at 7 tesla.

Purvis Lucian A B LAB Clarke William T WT Valkovič Ladislav L Levick Christina C Pavlides Michael M Barnes Eleanor E Cobbold Jeremy F JF Robson Matthew D MD Rodgers Christopher T CT

Magnetic resonance in medicine 20170228 6

<h4>Purpose</h4>Phosphorus (<sup>31</sup> P) metabolites are emerging liver disease biomarkers. Of particular interest are phosphomonoester and phosphodiester (PDE) "peaks" that comprise multiple overlapping resonances in <sup>31</sup> P spectra. This study investigates the effect of improved spectral resolution at 7 Tesla (T) on quantifying hepatic metabolites in cirrhosis.<h4>Methods</h4>Five volunteers were scanned to determine metabolite T<sub>1</sub> s. Ten volunteers and 11 patients with l ...[more]

PMID: 28244131

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Project description:BackgroundPrevious in vivo proton MR spectroscopy (MRS) studies have demonstrated the possibility of quantifying amide groups of conjugated bile acids (NHCBA), olefinic lipids and cholesterol (OLC), choline-containing phospholipids (CCPLs), taurine and glycine conjugated bile acids (TCBA, GCBA), methylene group of lipids (ML), and methyl groups of bile acids, lipids, and cholesterol (BALC1.0, BALC0.9, and TBAC) in the gallbladder, which may be useful for the study of cholestatic diseases and cholangiopathies. However, these studies were performed at 1.5T and 3T, and higher magnetic fields may offer improved spectral resolution and signal intensity.PurposeTo develop a method for gallbladder MRS at 7T.Study typeRetrospective, technical development.PopulationTen healthy subjects (five males and five females), two patients with primary biliary cholangitis (PBC) (one male and one female), and one patient with primary sclerosing cholangitis (PSC) (female).Field strength/sequenceFree-breathing single-voxel MRS with a modified stimulated echo acquisition mode (STEAM) sequence at 7T.AssessmentPostprocessing was based on the T2 relaxation of water in the gallbladder and in the liver. Concentrations of biliary components were calculated using water signal. All data were corrected for T2 relaxation times measured in healthy subjects.Statistical testsThe range of T2 relaxation time and concentration per bile component, and the resulting mean and standard deviation, were calculated.ResultsThe concentrations of gallbladder components in healthy subjects were: NHCBA: 93 ± 66 mM, OLC: 154 ± 124 mM, CCPL: 42 ± 17 mM, TCBA: 48 ± 35 mM, GCBA: 67 ± 32 mM, ML: 740 ± 391 mM, BALC1.0: 175 ± 92 mM, BALC0.9: 260 ± 138 mM, and TBAC: 153 ± 90 mM. Mean concentrations of all bile components were found to be lower in patients.Data conclusionThis work provides a protocol for designing future MRS investigations of the bile system in vivo.Evidence level2 TECHNICAL EFFICACY STAGE: 1.

Project description:Background Stiffness thresholds for liver MR elastography in children vary between studies and may differ from thresholds in adults. Normative liver stiffness data are needed to optimize diagnostic thresholds for children. Purpose To determine normal liver stiffness, and associated normal ranges for children, as measured with MR elastography across vendors and field strengths. Materials and Methods This was a prospective multicenter cohort study (ClinicalTrials.gov identifier: NCT03235414). Volunteers aged 7-17.9 years without a known history of liver disease were recruited at four sites for a research MRI and blood draw between February 2018 and October 2019. MRI was performed on three vendor platforms and at two field strengths (1.5 T and 3.0 T). All MRI scans were centrally analyzed; stiffness, proton density fat fraction (PDFF), and R2* values were expressed as means of means. Mean and 95% confidence intervals (CIs) for liver stiffness were calculated. Pearson correlation coefficient (r), two-sample t test, or analysis of variance was used to assess univariable associations. Results Seventy-one volunteers had complete data and no documented exclusion criterion (median age, 12 years; interquartile range [IQR], 10-15 years; 39 female participants). Median body mass index percentile was 54% (IQR, 32.5%-69.5%). Mean liver stiffness was 2.1 kPa (95% CI: 2.0, 2.2 kPa) with mean ± 1.96 kPa standard deviation of 1.5-2.8 kPa. Median liver PDFF was 2.0% (IQR, 1.7%-2.6%). There was no association between liver stiffness and any patient variable or MRI scanner factor. Conclusion Mean liver stiffness measured with MR elastography in children without liver disease was 2.1 kPa (similar to that in adults). The 95th percentile of normal liver stiffness was 2.8 kPa. Liver stiffness was independent of sex, age, or body mass index and did not vary with MRI scanner vendor or field strength. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Yin in this issue.

Dataset Information

Phosphodiester content measured in human liver by in vivo ³¹ P MR spectroscopy at 7 tesla.

Purpose

Methods

Results

Publications

Phosphodiester content measured in human liver by in vivo <sup>31</sup> P MR spectroscopy at 7 tesla.

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Dataset Information

Phosphodiester content measured in human liver by in vivo 31 P MR spectroscopy at 7 tesla.

Purpose

Methods

Results

Publications

Phosphodiester content measured in human liver by in vivo <sup>31</sup> P MR spectroscopy at 7 tesla.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Phosphodiester content measured in human liver by in vivo ³¹ P MR spectroscopy at 7 tesla.