Liver MRI susceptibility-weighted imaging (SWI) and T2* mapping in the presence of steatosis and fibrosis

Abstract Purpose To show that both susceptibility-weighted imaging (SWI) and T2*-mapping are dependent on liver steatosis, which should be taken into account when using these parameters to grade liver fibrosis and cirrhosis. Methods In this prospective study, a total of 174 patients without focal liver disease underwent multiparametric MRI at 3 T including SWI, T1- and T2* mapping, proton density fat fraction (PDFF) quantification and MR elastography. SWI, T2* and T1 were measured in the liver (4 locations), as well as in paraspinal muscles, to calculate the liver-to-muscle ratio (LMR). Liver and LMR values were compared among patients with different steatosis grades (PDFF  20%), patients with normal, slightly increased and increased liver stiffness ( 3.5 kPa, respectively). ANOVA with Bonferroni-corrected post hoc tests as well as a multivariate analysis were used to compare values among groups and parameters. Results SWI and T2* both differed significantly among groups with different steatosis grades (p  Conclusion SWI and T2*-mapping are strongly dependent on the liver steatosis grades. Nevertheless, both parameters are useful predictors for liver fibrosis when using a multiparametric approach.