title: Ultrasonographic findings of type IIIa biliary atresia.
abstract: OBJECTIVE
  To describe the ultrasonographic (US) findings of type IIIa biliary atresia.
  
  
  METHODS
  We retrospectively reviewed a medical database of patients pathologically confirmed to have biliary atresia, Kasai type IIIa, between January 2002 and May 2013 (n=18). We evaluated US findings including the visible common bile duct (CBD), triangular cord thickness, gallbladder size and shape, and subcapsular flow on color Doppler US; laboratory data; and pathological hepatic fibrosis grades. We divided them into two groups-those with visible (group A) and invisible (group B) CBD on US-and compared all parameters between the two groups.
  
  
  RESULTS
  CBD was visible on US in five cases (27.8%; group A) and invisible in 13 cases (72.2%; group B). US was performed at an earlier age in group A than in group B (median, 27 days vs. 60 days; P=0.027) with the maximal age of 51 days. A comparison of the US findings revealed that the triangular cord thickness was smaller (4.1 mm vs. 4.9 mm; P=0.004) and the gallbladder length was larger (20.0 mm vs. 11.7 mm; P=0.021) in group A. The gallbladder shape did not differ between the two groups, and the subcapsular flow was positive in all cases of both groups. There was no significant difference in the laboratory data between the two groups. Upon pathological analysis, group A showed low-grade and group B showed low- to high-grade hepatic fibrosis.
  
  
  CONCLUSIONS
  When CBD is visible on US in patients diagnosed with type IIIa biliary atresia, other US features could have a false negative status. A subcapsular flow on the color Doppler US would be noted in the type IIIa biliary atresia patients.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seung-Seob
authors.identifier: 0000-0001-6071-306X
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Myung-Joon
authors.identifier: 0000-0002-4608-0275
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Mi-Jung
authors.identifier: 0000-0003-3244-9171
authors.initials: MJ
authors.lastname: Lee
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Choon-Sik
authors.identifier: 0000-0003-2010-6710
authors.initials: CS
authors.lastname: Yoon
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seok Joo
authors.identifier: 0000-0001-5224-1437
authors.initials: SJ
authors.lastname: Han
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hong
authors.identifier: 0000-0002-3660-7483
authors.initials: H
authors.lastname: Koh
keywords: Biliary atresia; Common bile duct; Ultrasonography