Objective To investigate the value of 3.0 T MRI in-phase/opposed-phase (IP-OP) imaging features in the quantitative assessment of hepatic steatosis after liver transplantation.

Methods Clinical data of 115 patients who underwent liver transplantation and completed MRI IP-OP examination and liver biopsy within 3 months were retrospectively collected. According to the gold standard of pathological results, patients were divided into the steatosis group (n=18) and the non-steatosis group (n=97). The relative signal intensity of hepatic parenchyma was measured on MRI IP-OP sequences, and the hepatic fat fraction (HFF) was calculated. Differences in clinical data and imaging features between the two groups were compared, and the efficacy of HFF in the diagnosis of graft hepatic steatosis was evaluated using the receiver operating characteristic (ROC) curve.

Results Among the 115 recipients, 18 cases were diagnosed with hepatic steatosis by liver biopsy, including 13 cases of mild steatosis, 3 cases of moderate steatosis and 2 cases of severe steatosis. Compared with the non-steatosis group, the steatosis group had a lower proportion of hepatitis B virus (HBV)-related hepatocellular carcinoma, higher proportions of HBV-related liver failure and alcoholic liver cirrhosis, and higher platelet levels (all P<0.05). There were statistically significant differences in hepatic imaging features between the two groups (all P<0.05). The ROC curve showed that the area under the curve (AUC) of the quantitative value calculated by IP-OP in the diagnosis of graft hepatic steatosis was 0.925 (95% confidence interval 0.870-0.980).

Conclusions 3.0 T MRI IP-OP sequence may accurately and non-invasively quantitatively assess the severity of hepatic steatosis after liver transplantation, which is of great value for the early detection of graft hepatic steatosis and the guidance of clinical intervention.