| 1. |
- Norén, Bengt, 1955-, et al.
(författare)
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Absolute quantification of human liver metabolite concentrations by localized in vivo 31P NMR spectroscopy in diffuse liver disease
- 2005
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 15:1, s. 148-157
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Tidskriftsartikel (refereegranskat)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-β, 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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| 2. |
- Norén, Bengt, 1955-, et al.
(författare)
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Separation of advanced from mild fibrosis in diffuse liver disease using 31P magnetic resonance spectroscopy
- 2008
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Ingår i: European Journal of Radiology. - : Elsevier. - 0720-048X .- 1872-7727. ; 66:2, s. 313-320
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Tidskriftsartikel (refereegranskat)abstract
- 31P-MRS using DRESS was used to compare absolute liver metabolite concentrations (PME, Pi, PDE, γATP, αATP, βATP) 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 10.5 mM 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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| 3. |
- Norén, Bengt, et al.
(författare)
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Visual assessment of biliary excretion of Gd-EOB-DTPA in patients with suspected diffuse liver disease–A biopsy-verified prospective study
- 2015
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Ingår i: European Journal of Radiology Open. - : Elsevier BV. - 2352-0477. ; 2, s. 19-25
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To qualitatively evaluate late dynamic contrast phases, 10, 20 and 30. min, after administration of Gd-EOB-DTPA with regard to biliary excretion in patients presenting with elevated liver enzymes without clinical signs of cirrhosis or hepatic decompensation and to compare the visual assessment of contrast agent excretion with histo-pathological fibrosis stage, contrast uptake parameters and blood tests. Methods: 29 patients were prospectively examined using 1.5T MRI. The visually assessed presence or absence of contrast agent for each of five anatomical regions in randomly reviewed time-series was summarized on a four grade scale for each patient. The scores, including a total visual score, were related to the histo-pathological findings, the quantitative contrast agent uptake parameters, expressed as KHep or LSC_N, and blood tests. Results: No relationship between the fibrosis grade or contrast uptake parameters could be established. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found. Comparing a sub-group of cholestatic patients with fibrosis score and Gd-EOB-DTPA dynamic parameters did not add any additional significant correlation. Conclusions: No correlation between visually assessed biliary excretion of Gd-EOB-DTPA and histo-pathological or contrast uptake parameters was found. A negative correlation between the visual assessment and alkaline phosphatase (ALP) was found.
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