MR imaging of biliary cysts in children with biliary atresia: clinical associations and pathologic correlation.

ABSTRACT

OBJECTIVE: We used MR imaging to determine the prevalence of biliary cysts in children with end-stage biliary atresia and evaluated the association of cysts with cholangitis, choleretic therapy, portoenterostomy, biochemical abnormalities, and MR findings of end-stage liver disease. The MR features of these cysts were correlated with their gross and histopathologic appearances. MATERIALS AND METHODS: We retrospectively reviewed 48 MR studies, clinical history, and laboratory data of 44 consecutive children with biliary atresia. RESULTS: MR images showed cysts in eight patients (18%). Cysts were statistically (p < .04) more common in patients who had a history of cholangitis, but were not associated with choleretic therapy or portoenterostomy surgery. Cysts were not statistically correlated with abnormalities in hepatic biochemical function or MR features of end-stage liver disease. Four livers with cysts were available for histopathologic study. Cysts were filled with bile, and most had an epithelial lining, consistent with a biliary origin. The epithelium was frequently ulcerated, accompanied by periportal extravasation of bile and inflammation. These findings suggest chronic obstruction with microscopic perforation. CONCLUSION: Biliary cysts are common in biliary atresia and may be related to previous episodes of cholangitis with attendant obstruction of biliary radicles. The presence of these cysts did not correlate with hepatic function, portoenterostomy surgery, or the extent of liver disease.