Pseudo gallbladder sign in biliary atresia--an imaging pitfall

Impact of gallbladder hypoplasia on hilar hepatic ducts in biliary atresia

BACKGROUND

Biliary atresia (BA) is an intractable disease of unknown cause that develops in the neonatal period. It causes jaundice and liver damage due to the destruction of extrahepatic biliary tracts,. We have found that heterozygous knockout mice of the SRY related HMG-box 17 (Sox17) gene, a master regulator of stem/progenitor cells in the gallbladder wall, exhibit a condition like BA. However, the precise contribution of hypoplastic gallbladder wall to the pathogenesis of hepatobiliary disease in Sox17 heterozygous embryos and human BA remains unclear.

METHODS

We employed cholangiography and histological analyses in the mouse BA model. Furthermore, we conducted a retrospective analysis of human BA.

RESULTS

We show that gallbladder wall hypoplasia causes abnormal multiple connections between the hilar hepatic bile ducts and the gallbladder-cystic duct in Sox17 heterozygous embryos. These multiple hilar extrahepatic ducts fuse with the developing intrahepatic duct walls and pull them out of the liver parenchyma, resulting in abnormal intrahepatic duct network and severe cholestasis. In human BA with gallbladder wall hypoplasia (i.e., abnormally reduced expression of SOX17), we also identify a strong association between reduced gallbladder width (a morphometric parameter indicating gallbladder wall hypoplasia) and severe liver injury at the time of the Kasai surgery, like the Sox17-mutant mouse model.

CONCLUSIONS

Together with the close correlation between gallbladder wall hypoplasia and liver damage in both mouse and human cases, these findings provide an insight into the critical role of SOX17-positive gallbladder walls in establishing functional bile duct networks in the hepatic hilus of neonates.

Interpretable artificial intelligence-based app assists inexperienced radiologists in diagnosing biliary atresia from sonographic gallbladder images

BACKGROUND

A previously trained deep learning-based smartphone app provides an artificial intelligence solution to help diagnose biliary atresia from sonographic gallbladder images, but it might be impractical to launch it in real clinical settings. This study aimed to redevelop a new model using original sonographic images and their derived smartphone photos and then test the new model's performance in assisting radiologists with different experiences to detect biliary atresia in real-world mimic settings.

METHODS

A new model was first trained retrospectively using 3659 original sonographic gallbladder images and their derived 51,226 smartphone photos and tested on 11,410 external validation smartphone photos. Afterward, the new model was tested in 333 prospectively collected sonographic gallbladder videos from 207 infants by 14 inexperienced radiologists (9 juniors and 5 seniors) and 4 experienced pediatric radiologists in real-world mimic settings. Diagnostic performance was expressed as the area under the receiver operating characteristic curve (AUC).

RESULTS

The new model outperformed the previously published model in diagnosing BA on the external validation set (AUC 0.924 vs 0.908, P = 0.004) with higher consistency (kappa value 0.708 vs 0.609). When tested in real-world mimic settings using 333 sonographic gallbladder videos, the new model performed comparable to experienced pediatric radiologists (average AUC 0.860 vs 0.876) and outperformed junior radiologists (average AUC 0.838 vs 0.773) and senior radiologists (average AUC 0.829 vs 0.749). Furthermore, the new model could aid both junior and senior radiologists to improve their diagnostic performances, with the average AUC increasing from 0.773 to 0.835 for junior radiologists and from 0.749 to 0.805 for senior radiologists.

CONCLUSIONS

The interpretable app-based model showed robust and satisfactory performance in diagnosing biliary atresia, and it could aid radiologists with limited experiences to improve their diagnostic performances in real-world mimic settings.

Prediction of Fetal Biliary Atresia Based on Second and Third-Trimester Ultrasound Characteristics

OBJECTIVE

 To explore the diagnostic performance of prenatal ultrasound in the prediction of biliary atresia (BA).

METHODS

 We prospectively collected cases of suspected biliary abnormalities in the 2^nd trimester of pregnancy and performed a series (at least 3) of prenatal ultrasound examinations in the 2^nd and 3^rd trimester. The presence of the gallbladder was examined each time, and its size and shape were assessed if the gallbladder was visible. The existence of other abnormalities was carefully evaluated. Neonatal ultrasound examination was conducted within 1 month after birth, and clinical data were followed-up for 6 months after birth.

RESULTS

 Among the 41 895 patients, 298 were suspected to have biliary abnormalities, while 82 patients were excluded due to loss to follow-up or induced labor caused by other abnormalities. A total of 216 patients were included in this study, and 15 were diagnosed with BA. We summarized the ultrasound findings of the gallbladders and defined a high-risk gallbladder for the prenatal diagnosis of BA. This was demonstrated to have the best diagnostic performance as a single parameter, with an area under the curve of 0.914 (95 %CI: 0.869-0.948). In addition, higher incidences of biliary cysts, right hepatic artery dilation, echogenic bowel, and ascites were observed in BA fetuses. Logistic regression analysis showed that the combination of 5 parameters had better diagnostic performance, with an area under the curve of 0.995 (95 %CI: 0.973-0.999).

CONCLUSION

 The fetal gallbladder was found to be a critical feature for the identification of BA. Concomitant abnormalities could be helpful to improve the accuracy of the diagnosis.

Neonatal diagnosis of biliary atresia: a practical review and update

Biliary atresia is challenging to diagnose because many of the clinical and imaging features of this condition overlap with those of other causes of cholestasis in newborns. When jaundice persists beyond 2 weeks of age, the neonate should be evaluated for cholestasis, and biliary atresia - the most common cause of neonatal cholestasis - should be considered. It is critical to diagnose biliary atresia early because failure to treat can result in hepatic fibrosis and death in less than 1 year. In this paper, we review the current diagnostic imaging methods, differential considerations and treatment options for biliary atresia.

Latest diagnostic performance of different ultrasonic features for biliary atresia

BACKGROUND

Early diagnosis of biliary atresia (BA) is an important clinical challenge.

PURPOSE

To summarize the latest diagnostic performance of different ultrasonic (US) features for BA.

MATERIAL AND METHODS

MeSH terms "biliary atresia" and "ultrasonography" and related hyponyms were used to search PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. Eligible articles were included and data were retrieved. The methodologic quality was assessed by version 2 of the Quality Assessment of Diagnostic Accuracy Studies tool. Estimated sensitivity and specificity of each US feature were calculated by Stata 14.0.

RESULTS

Fifty eligible studies on 5622 patients were included. Respective summary sensitivity and specificity were 77% (95% CI=69-84) and 98% (95% CI=96-99) for triangular cord sign (TCS) in 32 studies, 86% (95% CI=78-92) and 86% (95% CI=72-94) for shear wave elastography (SWE) in seven studies, 75% (95% CI=65-83) and 92% (95% CI=86-95) for gallbladder and biliary system abnormality (GBA) in 25 studies, and 81% (95% CI=69-90) and 79% (95% CI=67-87) for hepatic artery (HA) enlargement in seven studies. The overall US features from 11 studies yielded a summary sensitivity of 84% (95% CI=72-92) and specificity of 86% (95% CI=77-92).

CONCLUSION

TCS and GBA were the two most widely accepted US features currently used for differential diagnosis of BA. The newly developed SWE was an objective and convenient method with good diagnostic performance. HA enlargement can be used as an auxiliary sign.

The triangular cord ratio and the presence of a cystic lesion in the triangular cord. Suggested new ultrasound findings in the early diagnosis of Biliary Atresia

BACKGROUND

In biliary atresia (BA), the ultrasonic triangular cord (TC) sign is positive at ≥ 3 mm, but sometimes there is BA even if it is ≤ 3 mm. For improving the ultrasonographic diagnosis, we have established a new evaluation, adding the ratio of the anterior/posterior thickness (TC ratio) in the hyperechoic area and the presence of a cystic lesion in the triangular cord (TCC).

METHODS

We examined 24 cases of suspected BA who demonstrated acholic stools from 2006 to 2020. We retrospectively reviewed the timing of ultrasonographic diagnosis, the gallbladder diameter, gallbladder mucosal irregularity, the TC sign, TCC, and the TC ratio.

RESULTS

In the BA group (n = 10) vs the Non-BA group (n = 14), the age at ultrasonography was 75 ± 41.7 vs. 81 ± 39.1 days (p = 0.72), the gallbladder diameter was 12.1 ± 9.7 vs. 24.2 ± 6.96 mm (p = 0.02), irregularity of gallbladder mucosa was 7 cases vs. 1 case (p < 0.01), and TC sign was 3.9 ± 1.3 vs. 2.0 ± 0.49 mm (p = 0.01), respectively. TCC was observed in 8/10 cases in the BA group and none in the Non-BA group (p < 0.01). TC ratio was 3.40 ± 0.68 (BA group) and 1.59 ± 0.41 (Non-BA group) (p < 0.01).

CONCLUSION

The ultrasonic TC ratio improves the diagnostic accuracy of BA. TCC is a specific finding in the BA group.

Practical approach to imaging diagnosis of biliary atresia, Part 1: prenatal ultrasound and magnetic resonance imaging, and postnatal ultrasound

We present a practical approach to imaging in suspected biliary atresia, an inflammatory cholangiopathy of infancy resulting in progressive fibrosis and obliteration of extrahepatic and intrahepatic bile ducts. Left untreated or with failure of the Kasai procedure, biliary atresia progresses towards biliary cirrhosis, end-stage liver failure and death by age 3. Differentiation of biliary atresia from other nonsurgical causes of neonatal cholestasis is challenging because there is no single method for diagnosing biliary atresia, and clinical, laboratory and imaging features of this disease overlap with those of other causes of neonatal cholestasis. Concerning imaging, our systematic literature review shows that ultrasonography is the main tool for pre- and neonatal diagnosis. Key prenatal features, when present, are non-visualisation of the gallbladder, cyst in the liver hilum, heterotaxy syndrome and irregular gallbladder walls. Postnatal imaging features have a very high specificity when present, but a variable sensitivity. Triangular cord sign and abnormal gallbladder have the highest sensitivity and specificity. The presence of macro- or microcyst or polysplenia syndrome is highly specific but less sensitive. The diameter of the hepatic artery and hepatic subcapsular flow are less reliable. When present in the context of acholic stools, dilated intrahepatic bile ducts rule out biliary atresia. Importantly, a normal US exam does not rule out biliary atresia. Signs of chronic hepatopathy and portal hypertension (portosystemic derivations such as patent ductus venosus, recanalised umbilical vein, splenomegaly and ascites) should be actively identified for - but are not specific for - biliary atresia.

Gallbladder wall abnormality in biliary atresia of mouse Sox17+/- neonates and human infants

Biliary atresia (BA) is characterized by the inflammation and obstruction of the extrahepatic bile ducts (EHBDs) in newborn infants. SOX17 is a master regulator of fetal EHBD formation. In mouse Sox17+/- BA models, SOX17 reduction causes cell-autonomous epithelial shedding together with the ectopic appearance of SOX9-positive cystic duct-like epithelia in the gallbladder walls, resulting in BA-like symptoms during the perinatal period. However, the similarities with human BA gallbladders are still unclear. In the present study, we conducted phenotypic analysis of Sox17+/- BA neonate mice, in order to compare with the gallbladder wall phenotype of human BA infants. The most characteristic phenotype of the Sox17+/- BA gallbladders is the ectopic appearance of SOX9-positive peribiliary glands (PBGs), so-called pseudopyloric glands (PPGs). Next, we examined SOX17/SOX9 expression profiles of human gallbladders in 13 BA infants. Among them, five BA cases showed a loss or drastic reduction of SOX17-positive signals throughout the whole region of gallbladder epithelia (SOX17-low group). Even in the remaining eight gallbladders (SOX17-high group), the epithelial cells near the decidual sites were frequently reduced in the SOX17-positive signal intensity. Most interestingly, the most characteristic phenotype of human BA gallbladders is the increased density of PBG/PPG-like glands in the gallbladder body, especially near the epithelial decidual site, indicating that PBG/PPG formation is a common phenotype between human BA and mouse Sox17+/- BA gallbladders. These findings provide the first evidence of the potential contribution of SOX17 reduction and PBG/PPG formation to the early pathogenesis of human BA gallbladders.This article has an associated First Person interview with the joint first authors of the paper.

Is "gallbladder length-to-width ratio" useful in diagnosing biliary atresia?

BACKGROUND

The accurate assessment of gallbladder shape and wall abnormalities by ultrasound (US) in diagnosing biliary atresia (BA) remains a subjective determination. The objective of this study was to examine the reliability of gallbladder length-to-width ratio (LTWR) by US measurement for diagnosis of BA.

METHODS

One hundred infants with conjugated hyperbilirubinemia and unknown cause of jaundice who underwent transabdominal US from February 2009 to February 2017 were enrolled. The gallbladder classification and other detailed US findings were reviewed.

RESULTS

There were statistical differences in gallbladder lumen, classification, length, width and LTWR of gallbladder (all P < 0.05) between BA and non-BA groups. The gallbladder LTWR with a cutoff at 4.1 had the highest sensitivity of 71.7%, while the fibrotic cord thickness had the highest specificity of 95.9%. The combination of portal vein (PV) diameter > 4.4 mm, hepatic artery (HA) diameter > 1.2 mm, and gallbladder LTWR >4.1, provided much higher specificity (98%), odds ratio (11), and positive likelihood ratio (LR+) (10.6).

CONCLUSION

The gallbladder LTWR by US could be a suggestive US parameter for BA screening. The triad of PV diameter, HA diameter, and gallbladder LTWR yielded the highest specificity, odds ratio, and LR+ for diagnosing BA.

LEVEL OF EVIDENCE

Level III study of diagnostic test.

Neonatal Jaundice

Hyperbilirubinemia is a common occurrence in neonates; it may be physiological or pathological. Conjugated hyperbilirubinemia may result from medical or surgical causes, and can result in irreversible liver damage if untreated. The aim of imaging is the timely diagnosis of surgical conditions like biliary atresia and choledochal cysts. Abdominal ultrasound is the first line imaging modality, and Magnetic resonance cholangiopancreatography (MRCP) also has a role, especially in pre-operative assessment of choledochal cysts (CDCs). For biliary atresia, the triangular cord sign and gallbladder abnormalities are the two most useful ultrasound features, with a combined sensitivity of 95%. Liver biopsy has an important role in pre-operative evaluation; however, the gold standard for diagnosis of biliary atresia remains an intra-operative cholangiogram. Choledochal cysts are classified into types according to the number, location, extent and morphology of the areas of cystic dilatation. They are often associated with an abnormal pancreaticobiliary junction, which is best assessed on MRCP. Caroli's disease or type 5 CDC comprises of multiple intrahepatic cysts. CDCs, though benign, require surgery as they may be associated with complications like cholelithiasis, cholangitis and development of malignancy. Severe unconjugated hyperbilirubinemia puts neonates at high risk of developing bilirubin induced brain injury, which may be acute or chronic. Magnetic resonance imaging of the brain is the preferred modality for evaluation, and shows characteristic involvement of the globus pallidi, subthalamic nuclei and cerebellum - in acute cases, these areas show T1 hyperintensity, while chronic cases typically show hyperintensity on T2 weighted images.

Neonatal Cholestasis: A Pandora's Box

Neonatal cholestasis (NC) is a diagnostic dilemma frequently countered in a neonatal care unit. Early diagnosis is vital for achieving an optimal patient outcome as many causes of cholestasis such as biliary atresia are time-sensitive and amenable to treatment if analyzed and treated early. Nonetheless, it is not generally simple to analyze these cases right on time as some of them are regularly missed due to the presence of pigmented stools, lack of newborn metabolic screening, and named as instances of prolonged jaundice. In this manner, we prescribe to explore all reasons for prolonged jaundice stretching out past 14 days in neonates. Besides, we suggest that stool card ought to be a piece of release rundown for all newborn children being released from the nursery. This is of most extreme significance in the nation like India where guaranteeing customary follow-up is as yet a tough assignment. These stool cards will help in the early determination of patients with NC particularly biliary atresia and guarantee their auspicious cure. Another reason which needs exceptional say is parenteral nutrition–associated liver illness, as the proportion of preterm babies is getting greater and greater with better neonatal care. These extreme preterm infants are in the requirement for prolonged (>14 days) total parenteral nourishment because of which they are at high hazard for NC contrasted with their more developed peers. In this survey, we will give an understanding of clinical approach, differential diagnosis, and clinical review of NC.

Early differential diagnosis methods of biliary atresia: a meta-analysis

PURPOSE

To evaluate the accuracy of early differential diagnosis methods of biliary atresia in patients with infantile cholestasis.

METHODS

We searched PubMed, EMBASE and the Web of Science databases for articles evaluated the early differential diagnosis methods of biliary atresia. The methodological quality of each study was assessed with version 2 of the Quality Assessment of Diagnostic Accuracy Studies tool. Two reviewers extracted data independently. Pooled sensitivity, specificity, positive likelihood ratio (LR +), negative likelihood ratio (LR -), diagnostic odds ratio (DOR) with 95% CIs were calculated to assess each diagnosis method.

RESULTS

A total of 38 articles were included. Summary sensitivity and specificity were 77% (95% CI 74-80%) and 93% (95% CI 91-94%), respectively, for B-US in 23 studies; 96% (95% CI 92-98%) and 58% (95% CI 51-65%), respectively, for MRCP in five studies; 87% (95% CI 82-91%) and 78% (95% CI 74-82%), respectively, for acholic stool in seven studies; 84% (95% CI 78-89%) and 97% (95% CI 97-98%), respectively, for serum liver function test in seven studies; 96% (95% CI 94-97%) and 73% (95% CI 70-76%), respectively, for hepatobiliary scintigraphy in 18 studies; 98% (95% CI 96-99%) and 93% (95% CI 89-95%), respectively, for percutaneous liver biopsy in 11 studies.

CONCLUSION

The accuracy rate of percutaneous liver biopsy is better than all of the noninvasive methods. Take into consideration the advantages and disadvantages of the six methods, combination of multidisciplinary noninvasive diagnosis methods is the first choice for differential diagnosis of BA from other causes of neonatal cholestasis.

Neonatal Cholestasis - Differential Diagnoses, Current Diagnostic Procedures, and Treatment

Cholestatic jaundice in early infancy is a complex diagnostic problem. Misdiagnosis of cholestasis as physiologic jaundice delays the identification of severe liver diseases. In the majority of infants, prolonged physiologic jaundice represent benign cases of breast milk jaundice, but few among them are masked and caused by neonatal cholestasis (NC) that requires a prompt diagnosis and treatment. Therefore, a prolonged neonatal jaundice, longer than 2 weeks after birth, must always be investigated because an early diagnosis is essential for appropriate management. To rapidly identify the cases with cholestatic jaundice, the conjugated bilirubin needs to be determined in any infant presenting with prolonged jaundice at 14 days of age with or without depigmented stool. Once NC is confirmed, a systematic approach is the key to reliably achieve the diagnosis in order to promptly initiate the specific, and in many cases, life-saving therapy. This strategy is most important to promptly identify and treat infants with biliary atresia, the most common cause of NC, as this requires a hepatoportoenterostomy as soon as possible. Here, we provide a detailed work-up approach including initial treatment recommendations and a clinically oriented overview of possible differential diagnoses in order to facilitate the early recognition and a timely diagnosis of cholestasis. This approach warrants a broad spectrum of diagnostic procedures and investigations including new methods that are described in this review.

Differentiating biliary atresia from other causes of cholestatic jaundice

Diagnosis of biliary atresia (BA) in infants presenting with cholestatic jaundice (CJ) requires exploratory surgery with cholangiography. However, the lack of a standardized approach to preoperative evaluation of infants with CJ can lead to a high number of negative surgical explorations. We reviewed our experience with CJ and BA to determine preoperative variables that might reliably identify BA. Infants explored for possible BA over a 5-year period were retrospectively reviewed. Preoperative clinical indices and liver biopsy results were reviewed. Statistical analysis was conducted by Student's t test and Fisher's exact test (P < 0.05). Twenty patients were identified, 10 with BA and 10 without (50% negative exploration rate). Nuclear cholescintigraphy (HIDA) excretion into the gastrointestinal tract was absent in all BA and in 8 of 10 without BA. Hepatomegaly was more common in the BA group (OR = 9.3, P = 0.07). BA had higher mean (± standard error) serum gamma-glutamyl transpeptidase levels (542 ± 130 vs 139 ± 25.8 U/L in non-BA, P = 0.03). There were insignificant differences in sex, type of feeding, TPN exposure and sepsis between the two groups. Although our small sample size limits conclusions, we suggest screening infants with CJ by measuring GGT levels, absence of hepatomegaly, presence of cholic stools and/or excretion on HIDA scan to undergo pecutaneous liver biopsy given the lower likelihood of BA necessary.

Differentiating Biliary Atresia from Other Causes of Cholestatic Jaundice

Diagnosis of biliary atresia (BA) in infants presenting with cholestatic jaundice (CJ) requires exploratory surgery with cholangiography. However, the lack of a standardized approach to pre-operative evaluation of infants with CJ can lead to a high number of negative surgical explorations. We reviewed our experience with CJ and BA to determine preoperative variables that might reliably identify BA. Infants explored for possible BA over a 5–year period were retrospectively reviewed. Preoperative clinical indices and liver biopsy results were reviewed. Statistical analysis was conducted by Student's t test and Fisher's exact test ( P < 0.05). Twenty patients were identified, 10 with BA and 10 without (50% negative exploration rate). Nuclear cholescintigraphy (HIDA) excretion into the gastrointestinal tract was absent in all BA and in 8 of 10 without BA. Hepatomegaly was more common in the BA group (OR = 9.3, P = 0.07). BA had higher mean (6 standard error) serum gammaglutamyl transpeptidase levels (542 ± 130 vs 139 ± 25.8 U/L in non-BA, P = 0.03). There were insignificant differences in sex, type of feeding, TPN exposure and sepsis between the two groups. Although our small sample size limits conclusions, we suggest screening infants with CJ by measuring GGT levels, absence of hepatomegaly, presence of cholic stools and/or excretion on HIDA scan to undergo pecutaneous liver biopsy given the lower likelihood of BA necessary.

Ultrasonographic findings of type IIIa biliary atresia

Purpose:

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.

Conclusion:

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.