Abstract: Objective Analysis of ultrasound imaging features of biliary atresia and hepatitis in infants.
Methods Retrospective analysis of the preoperative sonographic features of 38 cases of biliary atresia（BA）confirmed by surgery in our hospital from June 2016 to October 2019 and 26 cases of infant hepatitis（IHS）discharged from hospital Image analysis for comparison.
Results Thirty-eight children were confirmed by pathology after operation，aged 31d to 90d.Twenty-six IHS children aged 19d to 8 months.Of the two groups，the gallbladder structure of the children in the BA group was mostly abnormal，IHS the children were mostly normal，and the difference was statistically significant（P<0.05）.Comparison of gallbladder size between the two groups was statistically significant（P<0.05）.Compared gallbladder shrinkage rate，the difference was statistically significant（P<0.05）.Based on the ultrasound The image showed that the outer diameter of the common bile duct was widened and hypoechoic in 28 of the 38 BA children，but there were no other abnormalities.In 24 of the 26 IHS children，the outer diameter of the common bile duct was not widened and hypoechoic，and the color blood flow signal of the lymphatic portal was CDFI.Of the 38 children BA 29 showed that the lumen closure at the confluence of left and right hepatic ducts was fibrous stripe-like ，3 had hepatic portal cysts，and the rest had normal structure;26 HIS had tubular structure at the hepatic portal.There were 35 BA cases of edema in the catchment area of the liver（widening of the Greenson sheath）and no edema in the other 3 cases;5 of the HIS cases showed widening of the Greenson sheath.The echo of the vascular wall in the liver was enhanced in the rest of the children.All the 38 children with BA had different degree of liver enlargement.Fifteen of HIS children had slightly larger livers.
Conclusion Ultrasonography has the advantages of convenience，good visualization，strong reproducibility，and dynamics.It can be used as the first choice for the differential diagnosis of BA and IHS.

Key words: ultrasound identification, infant hepatitis, biliary atresia