The Study Of Magnetic Resonance Imaging On Congenital Biliary Atresia

Object:To explore the Magnetic Resonance(MR) imaging features associated with biliary atresia (BA) and to evaluate the accuracy of MRI in the diagnosis of BA and helping to distinguish it from infantile hepatitis syndrome(IHS) by application of Logistic regression and receiver operating characteristic (ROC) curve.Patients and methods:Review the MR images owned by51infants suffering biliary atresia diagnosed by operation from January2009to June2012, then pick up61infants’MR images who were suffering IHS diagnosed by clinical follow-up until jaundice resolved. After analyzing the MRI findings with logistic stepwise regression, we screened multiple diagnostic parameters for BA and established a mathematical model for diagnosis. Then we assessed the diagnostic efficacy of the model and calculated the diagnostic cut-off points for BA using the ROC curve. MR imaging analysis included abnormalities of intra-and extrahepatic bile ducts, periportal abnormal signal, length of gallbladder, changes of liver and spleen in volume, triangle sign and pyoperitoneum, By testing of the table rank sum test, we can find out if there is significant difference between the MRC findings of the two groups.Results:(1) MR features of BA:small gallbladder, intrahepatic or hilar periportal thickening, triangle sign in the porta hepatis, nonvisualization of extrahepatic bile ducts, hepatosplenomegaly, pyoperitoneum.There is statistical difference between the two groups except intrahepatic periportal thickening(p=0.612).(2) Logistic regression using multivariate analysis the features mentioned above the establishment of the regression equation P=1/[1+e-(-30.255-4.576X1+5.89X2+0.225X3+1.473X4+9.36X5)].(X1=gallbladder length, X2=hilar periportal thickening, X3=liver transverse diameter, X4=extrahepatic bile ducts uncertain, X5=nonvisualization of extrahepatic bile ducts) to produce a predictive balue pre.(3) Pre, liver transverse diameter, extrahepatic bile ducts, hilar periportal thickening, gallbladder length in the are under the ROCcurve are:0.995,0.856,0.922,0.839and0.839.Pre largest are undue the curve.(4) According to ROC curve analysis, critical point of Pre, liver transverse diameter, gallbladder length, in BA clinical diagnosis are0.701,121.35mm,22.95mm.(5) By ROC curve analysis and Youden’s index of the largest cut-off poit for clinical diagnosis as a critical point in the Pre, liver transverse diameter, extrahepatic bile ducts, gallbladder length and hilar periportal thickening predict BA sensitivity and specificity are94.1%,100%;64.7%,92.8%;88.2%,91.3%;78.4%,79.7%,82.4%,85.5%.(6) Combined the features of MRI predict the diagnosis of BA maximum performancersensitivity, specificity, and missed diagnosis rate, misdiagnosis rate, positive predictive value, negative predictive value and accuracy are as follows:94.1%,100%,4.9%,0%,94.1%,98.6%,96.7%. Conclusion:1. Liver transverse diameter, extrahepatic bile ducts, gallbladder length and hilar periportal thickening of MRI on the indentification of BA from IHS are valuable.2. The model of logistic regression is helpful to improve the diagnostic efficacy of MRI for BA, Diagnostic value of combined features is better than a single feature of MRI.