Nghiên cứu giá trị siêu âm trong chẩn đoán teo mật bẩm sinh ở trẻ < 4 tháng

Value of Ultrasound in diagnosis of biliary atresia in infants younger than 4 months old

SUMMARY

Purpose: To evaluate prospectively the value of ultrasonography (US) in the diagnosis of biliary atresia (BA), with surgery as the reference standard.

Material and Methods: 98 fasting infants (< 4 months old) with jaundice, acholic stools and conjugated hyperbilirubinemia underwent detailed US studies performed by an experienced pediatric radiologist with a 5MHz curvilinear transducer and a 7.5MHz linear-array transducer. The following features were prospectively recorded: gallbladder morphology, size and contraction, triangular cord sign. The radiologist was blinded to results of other investigations. Sensitivity, specificity, and positive and negative predictive values were calculated for each US variable. BA and non-BA groups were compared by means of the Fisher exact test for categorical variables and an unpaired t test for continuous variables.

Result: Forty infants had surgically confirmed BA, and 58 had other documented causes of neonatal jaundice; the mean ages at US assessment were 57 and 58 days, respectively (P>0,5). Seven US features showed a significant difference between BA and non-BA groups (P< 0,01, Fisher exact test). The features with the greatest individual sensitivity and specificity, respectively, in the diagnosis of BA were triangular cord sign (87,5% and 94,8%), abnormal gallbladder wall (87,5% and 89,6%) and no contraction (90,6% and 89,6%).The gallbladder was significantly smaller in infants with BA than in those without BA (15,4mm vs 22,5 mm in length, P <0,01).

Conclusion: US is valuable in diagnosis of biliary atresia if patients fast enough. Multiple US features should be used to increase the accuracy of the diagnosis

Abbreviation: US: Ultrasound

BA: Biliary Atresia

TC: Triangular Cord

Key word: Billiary atresia, Triangle Cord