Inter- and intra-reader agreement for gadoxetic acid–enhanced MRI parameter readings in patients with chronic liver diseases

OBJECTIVES: To examine inter- and intra-observer agreement for four simple hepatobiliary phase (HBP)–based scores on gadoxetic acid (GA)–enhanced MRI and their correlation with liver function in patients with mixed chronic liver disease (CLD). METHODS: This single-center, retrospective study included 287 patients (62% male, 38% female, mean age 53.5 ± 13.7 years) with mixed CLD (20.9% hepatitis C, 19.2% alcoholic liver disease, 8% hepatitis B) who underwent GA-enhanced MRI of the liver for clinical care between 2010 and 2015. Relative liver enhancement (RLE), contrast uptake index (CUI), hepatic uptake index (HUI), and liver-to-spleen contrast index (LSI) were calculated by two radiologists independently using unenhanced and GA-enhanced HPB (obtained 20 min after GA administration) images; 50 patients selected at random were reviewed twice by one reader to assess intra-observer reliability. Agreement was assessed by intraclass correlation coefficient (ICC). The albumin-bilirubin (ALBI) score, the model of end-stage liver disease (MELD), and the Child-Turcotte-Pugh (CTP) score were calculated as standards of reference for hepatic function. RESULTS: Intra-observer ICCs ranged from 0.814 (0.668–0.896) for CUI to 0.969 (0.945–0.983) for RLE. Inter-observer ICCs ranged from 0.777 (0.605–0.874) for HUI to 0.979 (0.963–0.988) for RLE. All HBP-based scores correlated significantly (all p < 0.001) with the ALBI, MELD, and CTP scores and were able to discriminate patients with a MELD score ≥ 15 versus ≤ 14, with area under the curve values ranging from 0.760 for RLE to 0.782 for HUI. CONCLUSION: GA-enhanced, MRI-derived, HBP-based parameters showed excellent inter- and intra-observer agreement. All HBP-based parameters correlated with clinical and laboratory scores of hepatic dysfunction, with no significant differences between each other. KEY POINTS: • Radiological parameters that quantify the hepatic uptake of gadoxetic acid are highly reproducible. • These parameters can be used interchangeably because they correlate with each other and with scores of hepatic dysfunction. • Assessment of these parameters may be helpful in monitoring disease progression. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00330-019-06182-z) contains supplementary material, which is available to authorized users.