Ultrasound findings in biliary atresia: the role of triangular cord sign

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.

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.

Diagnostic value of anti-smooth muscle antibodies and liver enzymes in differentiation of extrahepatic biliary atresia and idiopathic neonatal hepatitis

BACKGROUND

We aimed to evaluate the diagnostic value of anti-smooth muscle antibodies (ASMA) and two liver markers (gamma-glutamyl transpeptidase [GGT] and alkaline phosphatase [ALP]) for differentiating between patients with extrahepatic biliary atresia (EHBA) and idiopathic neonatal hepatitis (INH).

MATERIALS AND METHODS

During April 2010-2011, all infants at 2 weeks of age who were diagnosed with cholestasis and admitted to Children's Hospital of Tabriz were enrolled. Based on the results of physical examination, laboratory, imaging and pathological studies, neonates were divided into two groups (EHBA and INH). Receiver operating characteristics analysis was used to define sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for ASMA, GGT and ALP.

RESULTS

Thirty neonates with cholestasis (18 with EHBA and 12 with INH) and mean age of 54.66 ΁ 25.86 days were enrolled. Total and direct bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and ASMA titres were highly not significant (P > 0.05) in patients with INH. GGT (P = 0.008) and ALP (P = 0.01) had statistically significant differences that were higher in patients with EHBA. The sensitivity, specificity, PPV and NPV, accuracy, LR+ and LR- of SMA in differentiating cases with BA were 66.7%, 75%, 80% 60%, 70%, 2.68 and 0.44, respectively. For GGT, the values were 88.9%, 66.7%, 80%, 80%, 79.1%, 3.08 and 0.31, respectively. Finally, for ALP, the values were 77.8%, 75%, 82.4%, 69.2%, 80%, 2.66 and 0.24, respectively.

CONCLUSION

Our study showed that ASMA may be a useful biomarker for differentiation of EHBA from INH. Further studies with larger samples are recommended for confirming the results of this study.

Value of hepatic subcapsular flow by color Doppler ultrasonography in the diagnosis of biliary atresia

BACKGROUND AND AIM

Diagnosis of biliary atresia (BA), particularly distinguishing it from other causes of neonatal cholestasis (NC), is challenging. Ultrasonography is a helpful investigation when evaluating NC. The aim was to determine the value of color Doppler ultrasound, particularly hepatic subcapsular flow, as a possible tool in early discrimination of BA from other causes of NC.

METHODS

Ultrasonographic and color Doppler findings of 27 BA patients were compared with that in 27 non-BA cholestasis patients and a control group of 22 non-hepatic neonates.

RESULTS

Hepatic artery diameter was significantly higher in BA (2.48 ± 0.55 mm) than that in non-BA group (1.91 ± 0.63 mm) (P = 0.001) and the control group (1.6 ± 0.47 mm) (P < 0.0001), while there were no statistically significant difference between BA and non-BA groups as regards portal vein diameter and flow, hepatic vein flow, and hepatic artery resistance index. The frequency of hepatic subcapsular flow was significantly higher in BA than that in non-BA group (96.3% vs 3.7%; P < 0.0001), while it was not detected in any of the non-hepatic control group. The presence of hepatic subcapsular flow had 96.3% sensitivity and specificity in predicting BA.

CONCLUSIONS

Color Doppler ultrasound findings could help significantly in discriminating BA from other causes of NC, among which hepatic subcapsular flow had the best performance. Considering the young age of BA patients (61.8 ± 15.1 days), hepatic subcapsular flow can help in early diagnosis of BA and prevent the delay in surgical correction.

Diagnostic accuracy of Doppler ultrasonography in differentiation between malignant and benign cervical lymphadenopathies in pediatric age group

Cervical lymphadenopathy is a relatively common finding in pediatric age group and is caused by a wide spectrum of diseases from transient infections to malignancies especially lymphomas. The present study was aimed at evaluating the diagnostic performance of grey-scale ultrasonography, color Doppler ultrasonography and power Doppler ultrasonography in differentiation of reactively and metastatically enlarged cervical lymph nodes in pediatric age group. Fifty children with cervical lymphadenopathies were assessed by ultrasonographic methods. In each patient, the longest (L) and transverse (T) diameters, L/T ratio and presence or absence of the normal hilar pattern were checked by grey-scale ultrasonography. Spectral parameters (resistive and pulsatility indices) and vascular distribution pattern of nodes were recorded by color and power Doppler ultrasonography, respectively. Following the ultrasonographic evaluations, biopsy and/or clinical follow up was applied for six months, based on the clinical and paraclinical findings. Statistical analyses were performed by chi-square test, independent t-test and receiver operator characteristic curves. The mean age of patients was 12.42 +/- 2.42 years. Twenty eight patients (56%) had malignant enlargement of lymph nodes. The mean value of L/T ratio in malignant group was 1.70 +/- 0.22 and 2.40 +/- 0.38 in non-malignant nodes (p < 0.001). Sensitivity, specificity and accuracy of combined grey-scale and power Doppler ultrasonography were 70, 86 and 81%, respectively. Combination of grey-scale and power Doppler ultrasonography is recommended for the differentiation between the malignant and benign lymphadenopathies in children. Moreover, our findings revealed no diagnostic role of color Doppler ultrasonography in the selection of malignant cervical lymph nodes in children.