Identification of abdominal MRI features associated with histopathological severity and treatment response in autoimmune hepatitis.

To identify abdominal contrast magnetic resonance imaging (MRI) features associated with histopathological severity, and treatment response in autoimmune hepatitis (AIH).

Patients and methods: AIH patients who had abdominal contrast MRI within 3 months of liver biopsy were retrospectively enrolled. Histopathological severity, liver volume, MRI features, laboratory tests, and treatment response were collected. MRI and serum models were constructed through stepwise univariate and multivariate logistic regression for diagnosing severe histopathology and predicting insufficient response (IR).

Results: One hundred AIH patients were included (median age: 57.0 years, 79.0% female). For diagnosing severe portal inflammation, reticular fibrosis and volume ratio of segment V-VIII to total liver (SV-SVIII/TLV) achieved an area under the receiver operating characteristic curve (AUROC) of 0.765 (95% CI 0.670-0.860). Severe confluent necrosis was modeled using hepatic fissure widening, reticular fibrosis, and volume ratio of segment I-III to segments IV-VIII, achieving an AUROC of 0.796 (95% CI 0.708-0.885). Severe histological activity was modeled using ascites, and SV-SVIII/TLV achieved an AUROC of 0.748 (95% CI 0.649-0.847). To diagnose cirrhosis, ascites, reticular fibrosis, and the volume ratio of segment I to the total liver were employed, yielding an AUROC of 0.833 (95% CI 0.716-0.949); IR (transaminases and/or immunoglobulin G remaining unnormal after 6 months of immunosuppressive treatment) was modeled using ascites, gallbladder wall edema, and transient hepatic attenuation difference, achieving an AUROC of 0.796 (95% CI 0.691-0.902).

Conclusion: The MRI models demonstrated relatively good performance in evaluating histopathological severity and treatment response. Combining MRI and serum models could enhance diagnostic and prognostic efficacy.

Key points: Question Abdominal contrast MRI may help clinicians better evaluate the histopathological severity and treatment response of autoimmune hepatitis (AIH), but there is currently limited research. Findings Models based on MRI features perform well in diagnosing severe portal inflammation, confluent necrosis, histological activity, and cirrhosis, as well as predicting insufficient response. Clinical relevance Abdominal contrast MRI, combined with serological parameters, provides a new and stronger noninvasive method for clinically assessing AIH progression and treatment.