Ultrasonographic Diagnosis of Biliary Atresia Based on a Decision-Making Tree Model

Diseases of bile duct in children

Several diseases originate from bile duct pathology. Despite studies on these diseases, certain etiologies of some of them still cannot be concluded. The most common disease of the bile duct in newborns is biliary atresia, whose prognosis varies according to the age of surgical correction. Other diseases such as Alagille syndrome, inspissated bile duct syndrome, and choledochal cysts are also time-sensitive because they can cause severe liver damage due to obstruction. The majority of these diseases present with cholestatic jaundice in the newborn or infant period, which is quite difficult to differentiate regarding clinical acumen and initial investigations. Intraoperative cholangiography is potentially necessary to make an accurate diagnosis, and further treatment will be performed synchronously or planned as findings suggest. This article provides a concise review of bile duct diseases, with interesting cases.

Development and validation of a model for early diagnosis of biliary atresia

BACKGROUND AND AIMS

Early diagnosis of biliary atresia (BA), particularly distinguishing it from other causes of neonatal cholestasis (NC), is challenging. This study aimed to design and validate a predictive model for BA by using the data available at the initial presentation.

METHODS

Infants presenting with NC were retrospectively identified from tertiary referral hospitals and constituted the model design cohort (n = 148); others were enrolled in a prospective observational study and constituted the validation cohort (n = 21). Clinical, laboratory, and abdominal ultrasonographic features associated with BA were assessed. A prediction model was developed using logistic regression and decision tree (DT) analyses.

RESULTS

Three predictors, namely, gamma glutamyl transpeptidase (γGT) level, triangular cord sign (TC sign), and gallbladder abnormalities, were identified as factors for diagnosing BA in multivariate logistic regression, which was used to develop the DT model. The area under the receiver operating characteristic (ROC) curve (AUC) value for the model was 0.905, which was greater than those for γGT level, TC sign, or gallbladder abnormalities alone in the prediction of BA.

CONCLUSION

A simple prediction model combining liver function and abdominal ultrasonography findings can provide a moderate and early estimate of the risk of BA in patients with NC.

['Triangular Cord' Sign in Biliary Atresia]

Biliary atresia is an unknown etiology of extrahepatic bile duct obstruction with a 'fibrous ductal remnant,' which represents the obliterated ductal remnant in the porta hepatis. The sonographic'triangular cord' (TC) sign has been reported to indicate a fibrous ductal remnant in the porta hepatis. In this review, we discuss the correlations among surgicopathological and sonographic findings of the porta hepatis and the definition, objective criteria, diagnostic accuracy, and differential diagnosis of the TC sign in 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.

An Unusual Cause of Cholestasis in an Infant: Biliary Atresia Type IIB

Biliary atresia (BA) is a progressive destructive cholangiopathy of unknown etiology that presents in early infancy. It has a worldwide frequency of 1:8,000–1:15,000 and is common in Asia than in the west. Based on the level at which the lumen of the extrahepatic duct is obliterated, BA is classified into three types. Type III is the commonest (∼85%) type and has the most proximal level of obstruction in the porta hepatis, while type II in which the atresia is at the level of the common hepatic duct, is the least common (∼2.5%) and has been rarely reported. Here, we report the imaging features of an infant with type IIB biliary atresia.

Development and Validation of a Nomogram Incorporating Ultrasonic and Elastic Findings for the Preoperative Diagnosis of Biliary Atresia

RATIONALE AND OBJECTIVES

To develop and validate a nomogram that incorporates the gallbladder morphology, hepatic elasticity, and demographic information for the prediction of biliary atresia (BA) in children.

MATERIALS AND METHODS

A total of 294 consecutive patients under the age of 70 days with cholestasis and suspected symptoms of BA were enrolled in this study, who were divided into a training cohort (150 patients) and a validation cohort (144 patients). Ultrasonography and two-dimensional shear wave elastography were performed for each patient prior to knowing the final diagnosis. Multivariate logistic regression was used to analyze the gallbladder morphologic feature in the sonogram (absence of gallbladder, small gallbladder, lower postprandial gallbladder contractibility, or abnormal gallbladder wall), hepatic elasticity and clinical data from the training cohort, and a diagnostic nomogram for BA was subsequently developed. The performance of the nomogram was respectively evaluated with respect to the discrimination and calibration in every cohort.

RESULTS

The multivariate analysis showed that the factors of age (p = 0.009), gallbladder morphology (p = 0.001) and hepatic elasticity (p < 0.001) could serve as independent predictive factors to differentiate between BA and other causes of cholestasis. The nomogram incorporating these three parameters showed good discrimination and satisfactory calibration, indicating a better performance compared to using only the gallbladder morphologic features and hepatic elasticity. The observed area under the receiver operator characteristic curve in the training cohort and validation cohort was 0.939 (p < 0.001) and 0.942 (p < 0.001), respectively, with a sensitivity of 95.5% and a specificity of 83.4% in the combined cohort.

CONCLUSION

The established nomogram shows a favored and improved predictive value for the diagnosis of BA.

Canine hepatobiliary anatomy, physiology and congenital disorders

The biliary system is an integral component of normal physiologic homeostasis and essential for survival. It acts as a conduit for the removal of detoxified and catabolised compounds as well as aids in fat digestion and absorption. Derangements in this system can have dangerous sequela that are associated with varying degrees of morbidity and mortality. Moreover, abnormalities in development of the biliary system can have varied and unpredictable changes on function and long-term outcome. The aims of this article were to review canine hepatobiliary anatomy, physiology and cholestasis as well as summarise congenital biliary disorders including human corollaries.

Neonatal cholestasis: development of a diagnostic decision algorithm from multivariate predictive models

Despite the recent advances involving molecular studies, the neonatal cholestasis (NC) diagnosis still relays on the expertise of medical teams. Our aim was to develop models of etiological diagnosis and unfavourable prognosis which may support a rationale diagnostic approach. We retrospectively analysed 154 patients born between January 1985 and October 2019. The cohort was divided into two main groups: (A) transient cholestasis and (B) other diagnosis (with subgroups) and also in two groups of outcomes: (I) unfavourable and (II) favourable. Multivariate logistic regression analysis identified the lower gestational age as the only variable independently associated with an increased risk of transient cholestasis and signs and/or symptoms of sepsis with infectious or metabolic diseases. Gamma-glutamyl transferase serum levels > 300 IU/L had a positive predictive value for both diagnosis of biliary atresia and for alpha-1-antitrypsin deficiency (A1ATD) and for unfavourable prognosis. A model of diagnosis for A1ATD (n = 34) showed an area under the ROC curve = 0.843 [confidence interval (CI): 0.773-0.912].Conclusion: This study identified some predictors of diagnosis and prognosis which helped to build a diagnostic decision algorithm. The unusually large subgroup of patients with A1ATD in this cohort emphasizes its predictive diagnostic model. What Is Known • The etiological diagnosis of neonatal cholestasis (NC) requires a step-by-step guided approach, and diagnostic models have been developed only for biliary atresia. • Current algorithms neither address the epidemiology changes nor the application of the new molecular diagnostic tools. What Is New • This study provides diagnostic predictive models for patients with A1ATD, metabolic/infectious diseases, and transient cholestasis, and two models of unfavourable prognosis for NC. • A diagnostic decision algorithm is proposed based on this study, authors expertise and the literature.

Fetal Hepatomegaly: Causes and Associations

Fetal hepatomegaly is associated with significant fetal morbidity and mortality. However, hepatomegaly might be overlooked when numerous other fetal anomalies are present, or it might not be noticed when it is an isolated entity. As the largest solid organ in the abdomen, the liver can be seen well with US or MRI, and the normal imaging characteristics are well described. The length of the fetal liver, which can be used to identify hepatomegaly, can be determined by measuring the liver from the diaphragm to the tip of the right lobe in the sagittal plane. Fetal hepatomegaly is seen with infection, transient abnormal myelopoiesis, liver storage and deposition diseases, some syndromes, large liver tumors, biliary atresia, and anemia. Some of these diagnoses are treatable during the fetal period. Attention to the associated findings and specific hepatic and nonhepatic imaging characteristics can help facilitate more accurate diagnoses and appropriate patient counseling.^©RSNA, 2020.

Comparison of the diagnostic value of virtual touch tissue quantification and virtual touch tissue imaging quantification in infants with biliary atresia

OBJECTIVE

This study aimed to compare the diagnostic performance of vital touch tissue quantification (VTQ) and virtual touch tissue imaging quantification (VTIQ) in diagnosing infants with biliary atresia (BA) from jaundiced infants.

METHODS

In this study, 26 jaundiced infants with BA, 33 jaundiced infants without BA, and 40 normal infants were enrolled. The hepatic shear wave velocity (SWV) of each infant was determined by VTQ and VTIQ examinations, respectively. Then, the receiver operating characteristic (ROC) curves were drawn and the area under the curve (AUC) and optimal cut-off values were calculated to evaluate the sensitivities and specificities of VTIQ and VTQ for BA.

RESULTS

The mean values of SWV of the control group measured by VTQ and VTIQ were (1.09 ± 0.18) m/s and (1.36 ± 0.21) m/s, respectively. The mean values of SWV of the non-BA group measured by VTQ and VTIQ were (1.30 ± 0.28) m/s and (1.52 ± 0.29) m/s, respectively. The mean values of SWV of the BA group measured by VTQ and VTIQ were (2.36 ± 0.36) m/s and (2.43 ± 0.29) m/s, respectively. The diagnostic threshold of VTQ and VTIQ to diagnose BA was 1.77 and 1.92 m/s. The sensitivities of VTQ and VTIQ to diagnose BA were 90.9% and 95.5%. The specificities of VTQ and VTIQ to diagnose BA were 68.4% and 78.9%.

CONCLUSION

Vital touch tissue quantification and VTIQ could help distinguish infants with BA from jaundiced infants by measuring the liver SWV values. VTIQ has higher sensitivity and specificity than VTQ.

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.

Assessment of Diffusion Tensor Imaging Parameters of Hepatic Parenchyma for Differentiation of Biliary Atresia from Alagille Syndrome

Objective

To assess diffusion tensor imaging (DTI) parameters of the hepatic parenchyma for the differentiation of biliary atresia (BA) from Alagille syndrome (ALGS).

Materials and Methods

This study included 32 infants with BA and 12 infants with ALGS groups who had undergone DTI. Fractional anisotropy (FA) and mean diffusivity (MD) of the liver were calculated twice by two separate readers and hepatic tissue was biopsied. Statistical analyses were performed to determine the mean values of the two groups. The optimum cut-off values for DTI differentiation of BA and ALGS were calculated by receiver operating characteristic (ROC) analysis.

Results

The mean hepatic MD of BA (1.56 ± 0.20 and 1.63 ± 0.2 × 10⁻³ mm²/s) was significantly lower than that of ALGS (1.84 ± 0.04 and 1.79 ± 0.03 × 10⁻³ mm²/s) for both readers (r = 0.8, p = 0.001). Hepatic MD values of 1.77 and 1.79 × 10⁻³ mm²/s as a threshold for differentiating BA from ALGS showed accuracies of 82 and 79% and area under the curves (AUCs) of 0.90 and 0.91 for both readers, respectively. The mean hepatic FA of BA (0.34 ± 0.04 and 0.36 ± 0.04) was significantly higher (p = 0.01, 0.02) than that of ALGS (0.30 ± 0.06 and 0.31 ± 0.05) for both readers (r = 0.80, p = 0.001). FA values of 0.30 and 0.28 as a threshold for differentiating BA from ALGS showed accuracies of 75% and 82% and AUCs of 0.69 and 0.68 for both readers, respectively.

Conclusion

Hepatic DTI parameters are promising quantitative imaging parameters for the detection of hepatic parenchymal changes in BA and ALGS and may be an additional noninvasive imaging tool for the differentiation of BA from ALGS.

Quantitative Contrast-Enhanced Ultrasound by Sonazoid in the Early Diagnosis of Biliary Atresia: An Experimental Study of Rats With Bile Duct Ligation

We aimed to investigate the feasibility of quantitative Sonazoid contrast-enhanced ultrasound (CEUS) in the diagnosis of biliary atresia (BA) at an early disease stage. First, liver tissue from 10 patients with BA and 10 patients with infantile hepatitis syndrome (IHS) was immunostained with cluster of differentiation 68 (CD68) to compare Kupffer cell counts. Then, quantitative Sonazoid CEUS was performed to evaluate the hyperplasia of the artery branches during the artery phase and changes in Kupffer cell counts during the Kupffer phase in a rat model of BA (common bile duct ligation). Based on our results, liver enhancement from Kupffer cells in BA patients was significantly higher than that in IHS patients (p = 0.026 < 0.05). Furthermore, quantitative CEUS showed that the liver enhancement intensity of rats with bile duct ligation was substantially greater than that of rats without bile duct ligation during the artery phase 3 d post-operation and the Kupffer phase 5 d post-operation. The increased enhancement intensity in the Kupffer phase was in agreement with the increase in Kupffer cell counts in pathologic staining (18/20, 90%). In conclusion, quantitative Sonazoid CEUS can detect the hyperplasia of artery branches in artery phase and the increase of Kupffer cells in Kupffer phase in the liver of BA rats at an early disease stage. Therefore, Sonazoid CEUS could potentially be a valuable non-invasive alternative for the diagnosis of BA.

Does Supersonic Shear Wave Elastography Help Differentiate Biliary Atresia from Other Causes of Cholestatic Hepatitis in Infants Less than 90 Days Old? Compared with Grey-Scale US

Purpose

To investigate the diagnostic performance of shear wave elastography (SWE) for measuring liver stiffness to identify and differentiate biliary atresia (BA) from cholestatic hepatitis in infants younger than 90 days.

Methods

A total of 138 infants younger than 90 days with cholestatic hepatitis were examined by SWE. The infants were subclassified into BA and nonbiliary atresia (non-BA) groups. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of hepatic Young's modulus measurements, the ultrasonic findings in the differential diagnosis of suspected BA, and the cut-off value to diagnose BA.

Results

In all infants with cholestatic hepatitis, the cut-off value of hepatic Young's modulus to differentiate the BA group from the non-BA group was 12.35 kPa and the area under the ROC curve (AUC) was 0.937, with a sensitivity of 84.3% and a specificity of 89.7%; nevertheless the AUC of the abnormal gallbladder (AbGB) was 0.940, with a sensitivity of 96.1% and a specificity of 92.0%. In the parallel test, triangular cord (TC) sign combined with AbGB had the best diagnostic performance and the AUC was 0.960, with a sensitivity of 100% and a specificity of 92.0%. In the serial test, SWE combined with AbGB achieved the best diagnostic performance; the AUC was 0.902, the sensitivity and specificity were 80.4% and 100%, respectively.

Conclusions

SWE could not only help differentiate BA from cholestatic hepatic diseases but also increase the diagnostic specificity when combined with grey-scale ultrasound in the serial test.

Ultrasound findings in paediatric cholestasis: how to image the patient and what to look for

Paediatric biliary tract and gallbladder diseases include a variety of entities with a wide range of clinical presentations. Cholestasis represents an impaired secretion of bilirubin by hepatocytes, manifesting with high blood levels of conjugated bilirubin and jaundice. Various causes may be involved, which can be recognised analysing blood tests and hepatobiliary imaging, while sometimes liver biopsy or surgery may be necessary. High-resolution real-time ultrasonography is an important tool for differentiation of obstructive and non-obstructive causes of jaundice in infants and children. In this paper, we briefly review the normal anatomy and the ultrasound aspects of main pathologies affecting gallbladder and biliary tree in neonatal and paediatric age.

Risk Estimation for Biliary Atresia in Patients with Neonatal Cholestasis: Development and Validation of a Risk Score

Purpose To develop and validate a scoring system based on clinical and imaging features to predict the risk for biliary atresia in patients with neonatal cholestasis. Materials and Methods Patients with neonatal cholestasis who underwent both ultrasonography (US) and hepatobiliary scintigraphy (n = 480) were retrospectively identified from two tertiary referral hospitals from January 2000 to February 2017. Patients from one hospital were classified as the derivation cohort (n = 371), and those from the other hospital were classified as the validation cohort (n = 109). Clinical and imaging features associated with biliary atresia were assessed. Histopathologic or intraoperative cholangiographic findings served as the reference standard for biliary atresia. A prediction model was developed by using logistic regression and was then transformed into a scoring system. The scoring system was internally and externally validated. Results Among the 371 patients in the derivation cohort, 97 (26.15%) had biliary atresia. A scoring system was constructed with the following variables: full-term birth, presence of the triangular cord sign at US, abnormal gallbladder morphology at US, and failure of radioisotope excretion to the small bowel at hepatobiliary scintigraphy. The maximum possible score with this system is 7 points. This system enabled differentiation of biliary atresia in the derivation cohort (C statistic, 0.981; 95% confidence interval [CI]: 0.970, 0.992) and the validation cohort (C statistic, 0.995; 95% CI: 0.987, 1.000). The risk score also showed good calibration in both the derivation and the validation cohorts (P = .328 and P = .281, respectively). Conclusion A simple scoring system combining clinical and imaging features can help accurately estimate the risk for biliary atresia in patients with neonatal cholestasis.

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.

Diagnostic Performance of Sonographic Features in Patients With Biliary Atresia: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the diagnostic performance of sonographic features of biliary atresia in patients with infantile cholestasis.

METHODS

The Ovid-MEDLINE and EMBASE databases were searched for studies of the diagnostic performance of sonographic features of biliary atresia in patients with infantile cholestasis. A meta-analysis was performed to evaluate the diagnostic performance of the triangular cord sign and other sonographic features in patients with biliary atresia.

RESULTS

Seventeen eligible studies with 1444 patients were included. The triangular cord sign had high accuracy for diagnosing biliary atresia: the meta-analytic summary sensitivity and specificity were 85% (95% confidence interval, 77%-90%) and 97% (95% confidence interval, 94%-99%), respectively. The area under the hierarchical summary receiver operating characteristic curve was 0.97. Meta-regression analysis revealed that the cutoff thickness of the triangular cord sign (3 or 4 mm) was a significant factor affecting study heterogeneity (P < .01). The proportions of nonidentification of the gallbladder (GB) ranged from 0% to 53%. Abnormal GB morphologic characteristics, nonvisualization of the common bile duct, and the presence of hepatic subcapsular flow showed relatively high sensitivities and specificities.

CONCLUSIONS

The triangular cord sign and other sonographic features, including abnormal GB morphologic characteristics, nonvisualization of the common bile duct, and the presence of hepatic subcapsular flow, had high diagnostic performance for the diagnosis of biliary atresia.

Biliary atresia: Where do we stand now?

The pathway from clinical suspicion to establishing the diagnosis of biliary atresia in a child with jaundice is a daunting task. However, investigations available help to point towards the correct diagnosis in reasonable time frame. Imaging by Sonography has identified several parameters which can be of utility in the diagnostic work up. Comparison of Sonography with imaging by Nuclear medicine can bring out the significant differences and also help in appropriate imaging. The battery of Biochemical tests, available currently, enable better understanding of the line-up of investigations in a given child with neonatal cholestasis. Management protocols enable standardized care with optimal outcome. The place of surgical management in biliary atresia is undisputed, although Kasai procedure and primary liver transplantation have been pitted against each other. This article functions as a platform to bring forth the various dimensions of biliary atresia.