MR imaging findings in autoimmune hepatitis: correlation with clinical staging.

Purpose: To retrospectively evaluate the morphologic and enhancement features of the liver on magnetic resonance (MR) images obtained in patients with autoimmune hepatitis (AIH) and to determine if there is a correlation between MR imaging findings and severity of clinical disease as measured with the Mayo end-stage liver disease (MELD) score.

Materials And Methods: This study was compliant with the Health Insurance Portability and Accountability Act and approved by the institutional review board. The need for informed consent was waived. Thirty-two patients (29 female and three male patients; mean age, 44 years; age range, 14-69 years) undergoing treatment for AIH underwent unenhanced and gadolinium-enhanced MR imaging. Two radiologists reviewed all cases independently to determine the presence of patchy or heterogeneous liver enhancement, biliary duct changes, lymphadenopathy, and findings of portal hypertension. Fibrosis was graded as mild, moderate, or severe reticular (corresponding to a grading scale of 1-3) or as confluent. Agreement between radiologists was assessed by using kappa coefficients. Mean MELD scores were compared across fibrosis categories by using the Kruskal-Wallis analysis of variance.

Results: Of the 32 patients, two (6%) had no imaging findings of cirrhosis. Thirty patients (94%) had reticular fibrosis with a mean grade of 1.8. Six patients had confluent fibrosis, and all six had associated reticular fibrosis. Mild intrahepatic biliary duct dilatation involving the right and left lobes was observed in four patients (12%). Lymphadenopathy was observed in 12% of patients. None of the patients had hepatocellular carcinoma. There was no significant overall association between fibrosis grade and MELD score (P = .36).

Conclusion: Although fibrosis is a common feature in AIH and is often moderate to severe, no significant correlation between fibrosis grade and MELD score was found.