Three main non-invasive imaging methods are routinely used for the assessment of liver fibrosis and steatosis in patients with nonalcoholic fatty liver disease (NAFLD): the vibration-controlled transient elastography (VCTE) using the FibroScan device, the magnetic resonance imaging (MRI) based on proton density fat fraction (PDFF), and the magnetic resonance elastography (MRE). The purpose of our study is to evaluate the efficiency of the VCTE findings compared to the two others methods, and to analyze the impact of hepatic iron overload on these comparisons.
A clinical study was performed on 94 patients with NAFLD in the radiology department of ACRIM-Polyclinic Saint-Côme (France). The study also included 17 patients with hemochromatosis, measured from MRI. The liver tissues of all the patients were evaluated with 1) VCTE (including the controlled attenuation (CAP) and stiffness parameters), 2) MRI (fat fraction parameter), and 3) MRE (stiffness parameter) techniques. The performance of VCTE was assessed by estimating the area under the ROC curve (AUC) for patients without or with hemochromatosis. Spearman's correlation was used for the comparison of VCTE measurements to MRI and MRE.
VCTE-based stiffness and CAP were significantly correlated with PDFF and MRE measurements ( ) for the subgroup without hemochromatosis. The correlations failed for the subgroup with hemochromatosis.
VCTE and CAP measurements were not correlated with those from MR PDFF and MRE for patients with hemochromatosis. VCTE, PDFF and MRE modalities don't give concordant results for patients with hemochromatosis.Le texte complet de cet article est disponible en PDF.
Complementary imaging modalities are key to evaluate liver fibrosis and steatosis.
Hepatic iron overload is a limitation for US and MR elastographies measurements.
Adaptation of liver MRI protocol to provide quantitative cartography of iron.
Radiologist's awareness on the effect of iron level on the diagnostic result.
Keywords : Attenuation, Fat, Imaging techniques (elastography, US, MRI), Iron, Liver, Stiffness