Pseudo Gallbladder sign in biliary atresia—an imaging pitfall

Abstract

BackgroundUltrasound (US) is used to identify causes of neonatal cholestasis. We describe a potential sonographic pitfall, the “pseudo gallbladder,” in biliary atresia (BA).ObjectiveTo describe the Pseudo Gallbladder sign (PsGB sign).Materials and methodsSonograms/clinical records of 20 confirmed BA infants and 20 non-BA cases were reviewed retrospectively. For the BA group, preoperative sonography and surgical and pathological findings were examined. For the non-BA group, sonographic features and pathological findings were examined. The PsGB sign is defined as a fluid-filled structure, located in the expected region of the gallbladder, measuring ≤ 15 mm in length but without a well-defined or normal-appearing gallbladder wall.ResultsA recognizable gallbladder and normal gallbladder wall were present in all non-BA infants. However, none of the BA infants had a sonographically normal gallbladder. Seventy-three percent of BA patients had a PsGB, and in 27% no gallbladder or gallbladder-like structure was detected.ConclusionA gallbladder-like structure in BA is common and can be misinterpreted as a normal gallbladder, delaying diagnosis and therapy. Recognition of this imaging pitfall, described here as the pseudo gallbladder sign, will help avoid this error.

Ultrasonographic findings of type IIIa biliary atresia

“…Recently, several studies have also demonstrated that the small size and the abnormal morphology of the gallbladder on US were useful in distinguishing biliary atresia from neonatal hepatitis [1,18,30-32]. According to our results, the gallbladder length was significantly greater in group A than in group B.…”

“…Further, many previous studies have reported several US findings to diagnose biliary atresia, including a triangular cord sign, abnormal gallbladder length and shape, invisible common bile duct (CBD), and subcapsular flow on color Doppler US [1,18- 32]. However, some patients show equivocal US findings, requiring additional invasive diagnostic methods or leading to a delayed diagnosis.…”

Ultrasound for the Diagnosis of Biliary Atresia: A Meta-Analysis

“…Thirty-six of the 59 relevant articles were excluded (24 articles that did not satisfy eligibility or methods criteria, six case reports, four articles in languages other than English, and two letters to the editor). Thus, 23 articles fulfilled all inclusion criteria and were selected for data extraction and analysis [10,11,15,16,18,19,21,22,24,25,27,29,30,[35][36][37][38][39][40][41][42][43][44] (Fig. 1).…”

“…Twenty studies used gallbladder abnormalities for diagnosis [10,11,15,18,19,21,22,24,29,30,[35][36][37][38][39][40][41][42][43][44]. One study combined abnormalities with the triangular cord sign, so we could not extract valid data for analysis [39].…”

“…3A), and AUC of 0.97 (95% CI, 0.95-0.98) for the diagnosis of biliary atresia [10,11,15,16,19,21,22,24,25,27,29,30,35,36,37,38,39,40,42,43] (Fig. 3B).…”