Value of 2-point Dixon water-only Look-Locker T1 mapping on the assessment of liver fibrosis in chronic liver disease with hepatic steatosis

OBJECTIVES: To evaluate the influence of fat on the assessment of liver fibrosis in chronic liver disease using 2-point Dixon water-only Look-Locker T1 mapping by comparing the water-only derived sequence (W-Dixon) with in-phase (IP) and opposed-phase (OP)-based sequences. METHODS: A 2.89-T MRI examination included 2D 2-point Dixon Look-Locker T1 mapping and proton density fat fraction (PDFF) mapping. The correlations between liver T1 values and PDFF were assessed using the Spearman correlation coefficient. T1 values on each T1 map were compared among 3 FIB-4 index range groups (FIB-4 < 1.3, 1.3-2.67, > 2.67) in patients with and without hepatic steatosis using one-way analysis of variance and the Kruskal-Wallis test. RESULTS: A total of 204 patients with chronic liver disease were retrospectively evaluated. T1 values on IP or OP images were significantly correlated with PDFF (r = -0.373, 0.220), while no significant correlation was found between T1 values on W-Dixon images and PDFF (r = -0.071). In patients without hepatic steatosis, T1 values on each T1 map in the FIB-4 > 2.67 group were significantly higher than in the FIB-4 1.3-2.67 group (P < .01). Conversely, in patients with hepatic steatosis, only the W-Dixon sequence statistically differentiated the FIB-4 > 2.67 group from the FIB-4 1.3-2.67 group based on T1 values (P < .05). CONCLUSIONS: The assessment of liver fibrosis based on T1 values obtained by Dixon water-only T1 mapping was less influenced by the presence of fat. ADVANCES IN KNOWLEDGE: Two-point Dixon water-only Look-Locker T1 mapping minimizes the confounding effect of fat, enabling proper assessment of liver fibrosis in steatotic chronic liver disease.