Biliary Atresia: Triangular Cord Sign and 'Pseudo Gallbladder Sign' in Ultrasound Diagnosis
Clinical Context
Biliary atresia is a pediatric hepatobiliary pathology requiring timely ultrasound diagnosis, as early diagnosis is critical for treatment planning. Available literature describes characteristic imaging findings as well as imaging pitfalls of sonographic diagnosis.
Pseudo Gallbladder Sign
The pseudo gallbladder sign in biliary atresia is described as an imaging pitfall—Aziz S, Wild Y, Rosenthal P, Golstein RB. Pseudo gallbladder sign in biliary atresia—an imaging pitfall (Pediatr Radiol. 2011). The essence lies in the fact that the gallbladder may appear abnormally altered or create a false appearance on sonographic interpretation.
Another pitfall is specifically noted—gallbladder contraction in biliary atresia (gallbladder contraction in biliary atresia: a pitfall of ultrasound diagnosis—Ikeda S, Sera Y, Ohshiro H, Pediatr Radiol. 1998). This is important to consider when evaluating the gallbladder, as its appearance may be misleading.
Triangular Cord Sign
The triangular cord sign is traditionally recognized as a key sonographic sign of biliary atresia, reflecting fibrotic tissue in the hepatic hilum. Specific quantitative thresholds (cord thickness) are not provided in the available fragments—[clarify] according to the original source (Humphrey TM, Stringer MD. Biliary atresia: US diagnosis. Radiology. 2007).
Role of Elastography
Elastography is used as an adjunctive method. Literature indicates the utility of shear wave elastography for differentiating biliary atresia from neonatal hepatitis syndrome (Wang X, Qian L, Jia L et al. Utility of Shear Wave Elastography for Differentiating Biliary Atresia From Infantile Hepatitis Syndrome. J Ultrasound Med 2016). ARFI sonography was also applied when evaluating children with biliary atresia prior to liver transplantation (Hanquinet S et al., Pediatr Radiol 2016). Specific stiffness thresholds are not provided in the available fragments—[clarify].
Practical Conclusions
When biliary atresia is suspected, targeted evaluation of the hepatic hilum (triangular cord) and gallbladder status is necessary, keeping in mind interpretation pitfalls: the pseudo gallbladder sign and contracted gallbladder. Elastography serves as an adjunctive tool in differential diagnosis with neonatal hepatitis syndrome.
Frequently asked questions
What is the pseudo gallbladder sign in biliary atresia?
It is a described imaging pitfall in the literature in which the gallbladder creates a false sonographic appearance (Aziz et al., Pediatr Radiol. 2011).
Can the gallbladder contract in biliary atresia?
Yes, gallbladder contraction in biliary atresia is described as a pitfall of ultrasound diagnosis (Ikeda et al., Pediatr Radiol. 1998), which may complicate assessment.
Is elastography helpful in diagnosis?
Yes, shear wave elastography is described as useful for differentiating biliary atresia from neonatal hepatitis syndrome (Wang et al., 2016); ARFI was applied when evaluating prior to transplantation. Thresholds—[clarify].
What are the threshold values for the triangular cord sign?
Specific quantitative criteria are not provided in the available fragments—[clarify] according to the original source (Humphrey & Stringer, Radiology 2007).