A quantitative image analysis using MRI for diagnosis of biliary atresia.

PURPOSE: Biliary atresia is a life-threatening disease that needs early diagnosis and management. Recently, MRI images have been used for the diagnosis of biliary atresia with improved accuracy of diagnosis when other imaging modalities such as ultrasonography are equivocal. This study aimed to evaluate the juxta-hilar extrahepatic biliary tree using MRI images to determine a quantitative value for diagnosing biliary atresia.

MATERIALS AND METHODS: This retrospective study was approved by the Ethical Committee at Mackey Memorial Hospital (IRB Number: 15MMHIS149e). Between January 2010 and December 2015, twenty-five patients with surgically confirmed biliary atresia were enrolled (age 18-65 days). Another 25 patients with clinically or surgically diagnosed idiopathic neonatal hepatitis (age 6-64 days) and 20 patients with non-hepatobiliary disease (age 6-65 days) were considered control group and normal subjects, respectively. The diameter of the enlarged, T2-hyperintense structure was measured using MRI images by two radiologists both blinded. The cut-off value for a biliary atresia diagnosis was obtained by area under the curve analysis.

RESULTS: The diameter of the T2-hyperintense structure at porta hepatis in biliary atresia (4.79 ± 1.14 mm) is larger than in idiopathic neonatal hepatitis (1.72 ± 0.42 mm) or in non-hepatobiliary disease (1.72 ± 0.35 mm) (p < 0.05). The optimum cut-off value for diagnosing biliary atresia was 3.1 mm with 98% sensitivity and 98% specificity.

CONCLUSION: The value of the enlarged, T2-hyperintense structure measured on MRI images was significantly increased in biliary atresia and may be useful in diagnosing biliary atresia.