Biliary atresia in neonates and infants: triangular area of high signal intensity in the porta hepatis at T2-weighted MR cholangiography with US and histopathologic correlation

Preoperative imaging findings to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia

OBJECTIVES

To investigate the feasibility of using preoperative imaging indices to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia (BA).

MATERIALS AND METHODS

The retrospective review included 190 BA patients who underwent the Kasai procedure between 2000 and 2020, with preoperative US and/or MRI, excluding cases with less than 2-year follow-up period. Multivariable logistic regression analysis was performed to identify imaging indices to predict 2-year native liver survival. Kasai failure was defined as the need for liver transplantation or death within 2 years of the Kasai procedure.

RESULTS

Of the 90 patients included, all had preoperative US, and 61 also had MRI. Kasai failure occurred in 52% (47/90). Preoperative US identified gallbladder length (OR 0.40, 95% CI 0.17-0.95, p = 0.039; cutoff 1.6 cm, AUC 67.66) and biliary cysts (OR 24.64, 95% CI 1.97-308.08, p = 0.013) as significant Kasai failure predictors, with a combined accuracy of 73% (60/82). For patients having both preoperative US and MRI, significant predictors were hepatic artery diameter (OR 6.75, 95% CI 1.31-34.88, p = 0.023; cutoff 2 mm, AUC 73.83) and biliary cysts (OR 23.89, 95% CI 1.43-398.82, p = 0.027) on US, and gallbladder length (OR 0.25, 95% CI 0.08-0.76, p = 0.014; cutoff 1.2 cm, AUC 74.72) and spleen size (OR 2.53, 95% CI 1.02-6.29, p = 0.045; cutoff 6.9 cm, AUC 73.72) on MRI, with a combined accuracy of 85% (52/61).

CONCLUSION

Preoperative US and/or MRI enhance the 2-year native liver survival prediction in BA patients after the Kasai procedure.

CLINICAL RELEVANCE STATEMENT

BA patients with hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and absence of biliary cysts (US/MRI) have a decreased likelihood of 2-year native liver survival.

KEY POINTS

• Preoperative US and/or MRI can predict the probability of achieving 2-year native liver survival following the Kasai procedure. • Combining US and MRI improved the accuracy to 85% for predicting 2-year native liver survival in BA patients. • The hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and no biliary cysts (US/MRI) are significant predictors of Kasai failure in patients with biliary atresia.

[Postoperative Imaging Findings of Biliary Atresia]

The Kasai portoenterostomy is the first-line treatment for the restoration of the flow of bile to the small intestine in patients with biliary atresia. Various complications can occur after Kasai portoenterostomy, including ascending cholangitis, biliary cirrhosis, and portal hypertension. Of these potential complications, ascending cholangitis in the most common. In cases of patients having uncontrolled complications due to progressive liver cirrhosis, portal hypertension, or progressive hyperbilirubinemia, liver transplantation is the indicated as treatment plan. Lifelong follow-up, particularly involving imaging studies, is important for the identification of various complications arising from biliary atresia after Kasai portoenterostomy. Additionally, imaging studies play a crucial role in the evaluation of potential liver donors and recipients. US is a key imaging modality utilized in the management of patients who undergo Kasai portoenterostomy, while CT and MRI are imperative to obtaining an accurate diagnosis.

[Diagnostic Imaging of Biliary Atresia]

Biliary atresia is a rare but significant cause of neonatal cholestasis. An early and accurate diagnosis is important for proper management and prognosis. To diagnose biliary atresia, various imaging studies using ultrasonography, MRI, hepatobiliary scans, and cholangiography can be performed, although ultrasonography is more important for initial imaging studies. In this article, we review the findings of biliary atresia from various imaging modalities, including ultrasonography, MRI, hepatobiliary scans, and cholangiography. The known key imaging features include abnormal gallbladder size and shape, periportal thickening visible as a 'triangular cord' sign, invisible common bile duct, increased hepatic arterial flow, and combined anomalies. Aside from the imaging findings of biliary atresia, we also reviewed the diagnostic difficulty in the early neonatal period and the role of imaging in predicting hepatic fibrosis. We hope that this review will aid in the diagnosis of biliary atresia.

['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.

Ultrasound for the Diagnosis of Biliary Atresia: From Conventional Ultrasound to Artificial Intelligence

Biliary atresia is an aggressive liver disease of infancy and can cause death without timely surgical intervention. Early diagnosis of biliary atresia is critical to the recovery of bile drainage and long-term transplant-free survival. Ultrasound is recommended as the initial imaging strategy for the diagnosis of biliary atresia. Numerous ultrasound features have been proved helpful for the diagnosis of biliary atresia. In recent years, with the help of new technologies such as elastography ultrasound, contrast-enhanced ultrasound and artificial intelligence, the diagnostic performance of ultrasound has been significantly improved. In this review, various ultrasound features in the diagnosis of biliary atresia are summarized. A diagnostic decision flow chart for biliary atresia is proposed on the basis of the hybrid technologies, combining conventional ultrasound, elastography and contrast-enhanced ultrasound. In addition, the application of artificial intelligence in the diagnosis of biliary atresia with ultrasound images is also introduced.

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.

Practical approach for the diagnosis of biliary atresia on imaging, part 2: magnetic resonance cholecystopancreatography, hepatobiliary scintigraphy, percutaneous cholecysto-cholangiography, endoscopic retrograde cholangiopancreatography, percutaneous liver biopsy, risk scores and decisional flowchart

We aim to 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 to biliary cirrhosis, end-stage liver failure and death within the first years of life. Differentiating biliary atresia from other nonsurgical causes of neonatal cholestasis is difficult as 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. In this second part, we discuss the roles of magnetic resonance (MR) cholecystopancreatography, hepatobiliary scintigraphy, percutaneous biopsy and percutaneous cholecysto-cholangiography. Among imaging techniques, ultrasound (US) signs have a high specificity, although a normal US examination does not rule out biliary atresia. Other imaging techniques with direct opacification of the biliary tree combined with percutaneous liver biopsy have roles in equivocal cases. MR cholecystopancreatography and hepatobiliary scintigraphy are not useful for the diagnosis of biliary atresia. We propose a decisional flowchart for biliary atresia diagnosis based on US signs, including elastography, percutaneous cholecysto-cholangiography or endoscopic retrograde cholangiopancreatography and liver biopsy.

The Prognosis of Type III Biliary Atresia with Hilar Cyst

OBJECTIVE

To compare the outcome of biliary atresia (BA) patients with and without hilar cyst on preoperative ultrasound.

METHODS

A single center retrospective review of patients of BA with (n = 27) and without hilar cyst (n = 27) over a 5 y period was done. The patients were analyzed using propensity score matching to reduce selection bias. All patients were diagnosed as type III BA by histologic examination and cholangiograms. Clinicopathological characteristics and survival outcomes were compared between the two groups.

RESULTS

There were no significant intergroup differences between baseline characteristics and outcomes after Kasai portoenterostomy surgery in two groups. BA with hilar cyst group showed comparable survival outcomes to the BA without cyst group (cumulative 1-y, 2-y and 5-y overall survival rates with native liver 61.4% vs. 65.8%, P = 0.041; 45.0% vs. 49.0%, P = 0.57; 45.0% vs. 49.0%, P = 0.57). And the Kaplan-Meier survival curves showed no significant difference in cumulative survival with native liver between the two groups (P = 0.58).

CONCLUSIONS

Type III BA with hilar cyst had no better prognosis compared with Type III BA without cyst.

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.

Development and Assessment of Screening Nomogram for Biliary Atresia Based on Hepatobiliary Ultrasonographic Features

Objectives: Biliary atresia (BA) is a rare neonatal liver disease of which the early diagnosis remains a challenge for clinicians. Our center has established a nomogram diagnostic model based on clinical characteristics and liver function characteristics. We aim to develop and validate a nomogram that includes additional ultrasound and finds hepatobiliary abnormality with better BA early screening performance. Methods: In this single-center, retrospective cohort analysis, 1,001 neonatal obstructive jaundice (NOJ) patients between 2012 and 2015 were enrolled. Multivariable analysis was used to identify clinical characteristics, laboratory liver function characteristics, and ultrasonic features that may early screen BA. A nomogram was developed to predict the probability of BA using multiple logistic regression analysis. This nomogram was subsequently validated using another cohort of 501 NOJ patients between 2015 and 2017. Calibration curve analysis and decision curve analyses were performed to evaluate and interpret the nomogram's clinical benefits. Results: Gender, direct bilirubin (DB), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), fasting gallbladder visibility, fasting gallbladder filling, and common bile duct visibility were found to have profound statistical significance between the BA and non-BA groups (P < 0.05). The significant features were used to build the nomogram. The area under the receiver operating characteristic (ROC) curve (AUC) value of the novel nomogram (0.87) was superior to those of the former nomogram (0.83) and GGT alone (0.81) in the prediction of BA. The calibration curve revealed a close resemblance between the predicted and actual BA probabilities. Also, the net benefit from the decision curve analysis (DCA) of the nomogram (0.54) was superior to those of the former nomogram (0.49) and GGT alone (0.45) at 80% of threshold possibility. Conclusions: The nomogram has demonstrated better performance for BA screening by including additional information of the US finding, holding a promising future as a non-invasive method for BA patients.

Key imaging features for differentiating cystic biliary atresia from choledochal cyst: prenatal ultrasonography and postnatal ultrasonography and MRI

Purpose

This study compared clinical and radiologic differences between cystic biliary atresia (cBA) and choledochal cyst (CC) type Ia/b.

Methods

Infants (≤12 months old) who were diagnosed with cBA or CC type Ia/b from 2005 to 2019 were retrospectively reviewed. Imaging features on preoperative ultrasonography (US) and magnetic resonance imaging (MRI) were compared between the cBA and CC groups. Logistic regression and area under the receiver operating characteristic curve (AUC) analyses were performed for the diagnosis of cBA. Changes in cyst size were also evaluated when prenatal US exams were available.

Results

Ten patients (5.5% of biliary atresia cases) with cBA (median age, 48 days) and 11 infants with CC type Ia/b (Ia:Ib=10:1; median age, 20 days) were included. Triangular cord thickness on US (cutoff, 4 mm) showed 100% sensitivity and 90.9% specificity (AUC, 0.964; 95% confidence interval [CI], 0.779 to 1.000) and cyst size on MRI (cutoff, 2.2 cm) had 70% sensitivity and 100% specificity (AUC, 0.900; 95% CI, 0.690 to 0.987) for diagnosing cBA. Gallbladder mucosal irregularity on US and an invisible distal common bile duct on MRI were only seen in the cBA group (10 of 10). Only the CC group showed prenatal cysts exceeding 1 cm with postnatal enlargement.

Conclusion

Small cyst size (<1 cm) on prenatal US, triangular cord thickening (≥4 mm) and gallbladder mucosal irregularity on postnatal US, and small cyst size (≤2.2 cm) and an invisible distal common bile duct on MRI can discriminate cBA from CC type Ia/b in infancy.

Periportal thickening on magnetic resonance imaging for hepatic fibrosis in infantile cholestasis

BACKGROUND

Untreated neonatal cholestasis can progress to liver cirrhosis and end stage liver disease in infancy due to prolonged hepatocyte and biliary tree injury and may require liver transplantation. Therefore, non-invasive evaluation of hepatic fibrosis is important in infants with cholestasis.

AIM

To investigate the usefulness of periportal thickening (PT) measured on liver magnetic resonance imaging (MRI) for the assessment of hepatic fibrosis in infants with cholestasis including biliary atresia (BA).

METHODS

This retrospective study included infants less than 6 mo who underwent liver MRI and biopsy for the evaluation of infantile cholestasis. PT and spleen size were measured on MRI. Serologic assessment was based on aspartate transaminase to platelet ratio index (APRI). The grade of histopathologic fibrosis was assessed by the METAVIR grading system. Correlation and diagnostic performance of PT, normalized spleen size ratio (SR, using the upper normal size limit), and APRI for diagnosing hepatic fibrosis were obtained by receiver-operating characteristic (ROC) curve analysis.

RESULTS

A total of 155 patients were included, 110 of which were diagnosed with BA. Mean age at the time of MRI was 57.6 ± 34.4 d. There were positive correlations between fibrosis grade and PT and SR, even after adjusting age (all, P < 0.001). For the diagnosis of significant fibrosis (METAVIR grade F2-F4), the area under the ROC curve was 0.899 (95%CI: 0.840–0.941) for PT (cutoff, 4.2 mm), which was higher than 0.741 (95%CI: 0.664–0.808) for SR and 0.712 (95%CI: 0.634–0.782) for APRI (both, P < 0.001). For the diagnosis of cirrhosis (F4), the area under the ROC curve was the highest with SR as 0.790 (95%CI: 0.718–0.852).

CONCLUSION

Liver MRI findings of PT and SR are useful to assess clinically significant hepatic fibrosis (F2 and higher) in infants with cholestasis including BA.

Hepatic Subcapsular Flow as a Significant Diagnostic Marker for Biliary Atresia: A Meta-Analysis

Aim

Increasing evidence indicates that hepatic subcapsular flow (HSF) can serve as a noninvasive ultrasonographic marker for the early diagnosis of biliary atresia (BA). However, results regarding its diagnostic accuracy are inconsistent and inconclusive. We conducted this meta-analysis with an aim to systematically evaluate the diagnostic value of HSF in predicting BA.

Methods

A comprehensive literature search of four databases was conducted to identify the eligible studies. All analyses were performed using STATA 12.0.

Results

Nine studies from eight articles containing 368 patients and 469 controls were included in our meta-analysis. Briefly, the values for pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were 0.95 (95% CI 0.88-0.98), 0.92 (95% CI 0.85-0.96), 11.6 (95% CI 6.3-21.5), 0.06 (95% CI 0.02-0.14), 201 (95% CI 59-689), and 0.98 (95% CI 0.96-0.99), respectively. Additionally, metaregression along with subgroup analysis based on various covariates revealed the potential sources of heterogeneity and the detailed diagnostic value in each subgroup.

Conclusion

Our meta-analysis showed that HSF assay could provide high accuracy in predicting BA patients and non-BA individuals. However, further studies with better design and larger sample size are required to support the results of the present study.

Clinical utility of mono-exponential model diffusion weighted imaging using two b-values compared to the bi- or stretched exponential model for the diagnosis of biliary atresia in infant liver MRI

Purpose

To investigate the clinical utility of mono-exponential model diffusion weighted imaging (DWI) using two b-values compared to the bi- or stretched exponential model to differentiate biliary atresia (BA) from non-BA in pediatric liver magnetic resonance imaging (MRI).

Methods

Patients who underwent liver MRI with DWI for suspected BA from November 2017 to September 2018 were retrospectively included and divided into BA and non-BA groups. Laboratory results including γ-glutamyl transferase (γGT) were compared between the two groups using the Mann-Whitney U test and Fisher’s exact test. The hepatic apparent diffusion coefficient (ADC) 10 using ten b-values and ADC 2 using two b-values were obtained from the mono-exponential model. The slow diffusion coefficient (D), fast diffusion coefficient (D*), and perfusion fraction (f) were obtained from the bi-exponential model. The distributed diffusion coefficient (DDC) and heterogeneity index (α) were measured from the stretched exponential model. Parameters were compared between the two groups using a linear mixed model and diagnostic performance was assessed using the area under the curve (AUC) analysis.

Results

For 12 patients in the BA and five patients in the non-BA group, the ADC 10 (median 0.985 ×10⁻³ mm²/s vs. 1.332 ×10⁻³ mm²/s, p = 0.008), ADC 2 (median 0.987 ×10⁻³ mm²/s vs. 1.335 ×10⁻³ mm²/s, p = 0.017), D* (median 33.2 ×10⁻³ mm²/s vs. 55.3 ×10⁻³ mm²/s, p = 0.021), f (median 13.4%, vs. 22.1%, p = 0.009), and DDC (median 0.889 ×10⁻³ mm²/s vs. 1.323 ×10⁻³ mm²/s, p = 0.009) values were lower and the γGT (median 368.0 IU/L vs. 93.5 IU/L, p = 0.02) and α (median 0.699 vs. 0.556, p = 0.023) values were higher in the BA group. The AUC values for γGT (AUC 0.867 95% confidence interval [CI] 0.616–0.984), ADC 10 (AUC 0.963, 95% CI 0.834–0.998), ADC 2 (AUC 0.925, 95% CI 0.781–0.987), f (AUC 0.850, 95% CI 0.686–0.949), and DDC (AUC 0.925, 95% CI 0.781–0.987) were not significantly different, except for the D* and α values.

Conclusion

Patients with BA had lower ADC 10, ADC 2, D*, f, and DDC values and higher γGT and α values than those in the non-BA group. The diagnostic performance of ADC 2 using only two b-values showed excellent diagnostic performance and was not significantly different from that of γGT, ADC 10, f, and DDC for diagnosing BA.

Cholestasis in the Baby and Infant

Cholestasis in children is a serious condition due to various aetiologic factors. If children with jaundice present with acholic stool, dark urine colour, or direct hyperbilirubinaemia, the patient should be evaluated urgently. Early and timely diagnosis and initiation of appropriate treatment are extremely important determinants of morbidity and mortality. In the neonatal period, idiopathic neonatal cholestasis, alpha-1 antitrypsin deficiency, cholestasis from infections, and biliary atresia are the most common causes of cholestasis. Nowadays, with the development of genetic and molecular biological studies, the diagnosis of many diseases that have previously been evaluated as ‘idiopathic‘ can be made. It is the aetiological factor that determines the prognosis. The treatment plan is created in accordance with aetiological causes and in response to symptoms such as pruritus and malabsorption: this can be surgical treatment across a diverse spectrum, from biliary diversion to liver transplantation. In this study, the aetiology, diagnosis, and treatment of cholestasis in babies and infants are reviewed in the light of current literature.

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.

Ultrasound Evaluation of Biliary Atresia Based on Gallbladder Classification: Is 4 Hours of Fasting Necessary?

OBJECTIVES

The aim of this study was to evaluate the influence of fasting time on the ultrasound identification and exclusion of biliary atresia in jaundiced infants through the use of the gallbladder classification scheme and to test the value of the gallbladder classification scheme in the diagnosis of biliary atresia in inexperienced individuals.

METHODS

A total of 188 jaundiced infants were enrolled in this study. All patients received detailed abdominal sonograms. Diagnoses were confirmed via liver biopsy, surgical findings, or follow-up. Infants were grouped into either the fasting group (fasting time ≥ 4 h) or the nonfasting group (fasting time < 4 h). According to the gallbladder classification scheme, the gallbladders were classified into 4 types. The accuracy of diagnosing biliary atresia based on the gallbladder classification scheme was compared between the 2 groups. The gallbladders of 177 infants that were detectable by ultrasonography were used to compare the diagnostic performances between a junior radiologist and an experienced radiologist.

RESULTS

The accuracies in the diagnosis of biliary atresia with the gallbladder classification scheme were 86.3% (82 of 95 patients) for the fasting group and 93.5% (87 of 93 patients) for the nonfasting group (P = .100). The diagnostic accuracies of biliary atresia were 88.7% (157 of 177 patients) for the junior radiologist and 90.4% (160 of 177 patients) for the experienced radiologist (P = .250). The κ value for the agreement between the 2 radiologists was 0.859.

CONCLUSIONS

The performance of gallbladder diagnoses was not influenced by the fasting time with the use of the gallbladder classification scheme. Additionally, the gallbladder classification scheme may help junior radiologists to more effectively identify biliary atresia and nonbiliary atresia.

A quantitative image analysis using MRI for diagnosis of biliary atresia

PURPOSE

Biliary atresia is a life-threatening disease that needs early diagnosis and management. Recently, MRI images have been used for the diagnosis of biliary atresia with improved accuracy of diagnosis when other imaging modalities such as ultrasonography are equivocal. This study aimed to evaluate the juxta-hilar extrahepatic biliary tree using MRI images to determine a quantitative value for diagnosing biliary atresia.

MATERIALS AND METHODS

This retrospective study was approved by the Ethical Committee at Mackey Memorial Hospital (IRB Number: 15MMHIS149e). Between January 2010 and December 2015, twenty-five patients with surgically confirmed biliary atresia were enrolled (age 18-65 days). Another 25 patients with clinically or surgically diagnosed idiopathic neonatal hepatitis (age 6-64 days) and 20 patients with non-hepatobiliary disease (age 6-65 days) were considered control group and normal subjects, respectively. The diameter of the enlarged, T2-hyperintense structure was measured using MRI images by two radiologists both blinded. The cut-off value for a biliary atresia diagnosis was obtained by area under the curve analysis.

RESULTS

The diameter of the T2-hyperintense structure at porta hepatis in biliary atresia (4.79 ± 1.14 mm) is larger than in idiopathic neonatal hepatitis (1.72 ± 0.42 mm) or in non-hepatobiliary disease (1.72 ± 0.35 mm) (p < 0.05). The optimum cut-off value for diagnosing biliary atresia was 3.1 mm with 98% sensitivity and 98% specificity.

CONCLUSION

The value of the enlarged, T2-hyperintense structure measured on MRI images was significantly increased in biliary atresia and may be useful in diagnosing biliary atresia.

MRI-based decision tree model for diagnosis of biliary atresia

OBJECTIVES

To evaluate MRI findings and to generate a decision tree model for diagnosis of biliary atresia (BA) in infants with jaundice.

METHODS

We retrospectively reviewed features of MRI and ultrasonography (US) performed in infants with jaundice between January 2009 and June 2016 under approval of the institutional review board, including the maximum diameter of periportal signal change on MRI (MR triangular cord thickness, MR-TCT) or US (US-TCT), visibility of common bile duct (CBD) and abnormality of gallbladder (GB). Hepatic subcapsular flow was reviewed on Doppler US. We performed conditional inference tree analysis using MRI findings to generate a decision tree model.

RESULTS

A total of 208 infants were included, 112 in the BA group and 96 in the non-BA group. Mean age at the time of MRI was 58.7 ± 36.6 days. Visibility of CBD, abnormality of GB and MR-TCT were good discriminators for the diagnosis of BA and the MRI-based decision tree using these findings with MR-TCT cut-off 5.1 mm showed 97.3 % sensitivity, 94.8 % specificity and 96.2 % accuracy.

CONCLUSIONS

MRI-based decision tree model reliably differentiates BA in infants with jaundice. MRI can be an objective imaging modality for the diagnosis of BA.

KEY POINTS

• MRI-based decision tree model reliably differentiates biliary atresia in neonatal cholestasis. • Common bile duct, gallbladder and periportal signal changes are the discriminators. • MRI has comparable performance to ultrasonography for diagnosis of 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.

Pediatric cholangiopathies: diseases of the gallbladder and biliary tract

Pediatric gallbladder and bile duct disease encompasses a broad spectrum of processes, from congenital to developmental to neoplastic. We describe normal pediatric biliary anatomy and summarize the most common pathologic entities, with a focus on non-invasive imaging techniques and findings. Ultrasound is the first-line imaging modality in children with suspected biliary pathology based on its widespread availability, cost effectiveness, and lack of ionizing radiation. MRI and MRCP are often used for further evaluation in cases of diagnostic uncertainty and for surgical planning.

Focal Lesions in Fatty Liver: If Quantitative Analysis Facilitates the Differentiation of Atypical Benign from Malignant Lesions

To evaluate the diagnostic performance of quantitative analysis as an adjunctive diagnostic tool to contrast-enhanced ultrasound (US) for the differentiation of atypical benign focal liver lesions (FLLs) from malignancies in fatty liver. Twenty-seven benign FLLs and fifty-six malignant FLLs that appeared hyper-enhanced during the arterial phase with washout in the portal or late phase in fatty liver were analyzed. Chi-square tests and logistic regression were applied to identify the specific features. Three sets of criteria were assigned: 1) all FLLs subjected to routine contrast-enhanced US; 2) all FLLs subjected to quantification analysis and contrast-enhanced US; and 3) parts of FLLs that could not be diagnosed using contrast-enhanced US (n = 66, 75.9%) but instead were diagnosed using parametric features. The sensitivity, specificity, accuracy and area under the receiver operating characteristic curve (AUC) of the three sets of criteria were analyzed. The AUCs of the criterion set 2 were significantly higher than those of criterion set 1 (0.904 versus 0.792, P = 0.008). Criterion set 3 showed a relatively high sensitivity (90.2%) with a relatively high AUC (0.845). The quantification analysis offers improved diagnostic performance for the differential identification of atypical benign FLLs from malignancies in fatty liver.

A prospective pilot study: can the biliary tree be visualized in children younger than 3 months on Magnetic Resonance Cholangiopancreatography?

BACKGROUND

Magnetic resonance cholangiopancreatography (MRCP) could aid in the diagnosis of biliary atresia, a hepatic pathology with thin, irregular or interrupted biliary ducts. There is little published evidence of MRCP appearances in normal neonates and young infants.

OBJECTIVE

To assess the use of MR cholangiopancreatography in visualizing the biliary tree in neonates and infants younger than 3 months with no hepatobiliary disorder, and to assess this visibility in relationship to the child's age, weight, and sedation and fasting states.

MATERIALS AND METHODS

Between December 2008 and October 2010 our department performed MRI of the brain, orbits and face on 16 full-term neonates and infants. Each child was younger than 3 months (90 days) and without any hepatobiliary disorders. The children were scanned with a respiratory-gated 0.54 × 0.51 × 0.4-mm(3) 3-D MRCP sequence. We used a reading grid to assess subjectively the visibility of the extrahepatic bile ducts along with extrahepatic bile duct confluence. The visibility of the extrahepatic bile duct confluence was assessed against age, weight, and sedation and fasting states.

RESULTS

The extrahepatic bile duct confluence was seen in 10 children out of 16 (62.5%). In the neonate sub-group (corrected age younger than 30 days), the MRCP was technically workable and the extrahepatic bile duct confluence was seen in four cases out of eight (50%). This visualization was up to 75% in the subgroup older than 30 days. However, statistically there was no significant difference in visibility of the extrahepatic bile duct confluence in relationship to age, weight or MRCP performance conditions (feeding, fasting or sedation).

CONCLUSION

The complete normal biliary system (extrahepatic bile duct confluence included) is not consistently visualized in infants younger than 3 months old on non-enhanced MRCP. Thus the use of MRCP to exclude a diagnosis of biliary atresia is compromised at optimal time of surgery.

Extrahepatic biliary atresia with choledochal cyst: Prenatal MRI predicted and post natally confirmed: A case report

Extrahepatic biliary atresia (EHBA) is an uncommon cause of neonatal jaundice. Antenatal Magnetic Resonance Imaging (MRI) diagnosis of EHBA has not been published to the best of our knowledge till date. EHBA with cystic component is likely to be mistaken for choledochal cyst. A case that was antenatally predicted and postnatally confirmed by surgery and histopathology is being reported. All imaging signs are analyzed herewith. Imaging helps in the prediction of EHBA and also helps in early postnatal surgical referral which in turn improves the results of Kasai's portoenterostomy.

Accuracy of hepatobiliary scintigraphy for differentiation of neonatal hepatitis from biliary atresia: systematic review and meta-analysis of the literature

Hepatobiliary scintigraphy is an important diagnostic modality for work-up of neonatal cholestasis. Therefore, our objective was to evaluate the literature regarding the accuracy of hepatobiliary scintigraphy in differentiating biliary atresia from non-biliary atresia causes of cholestasis (collectively called neonatal hepatitis). Our search included Medline, SCOPUS and Google Scholar. Only studies using Tc-99 m-labeled immunodiacetic acid (IDA) derivatives were included. Overall, 81 studies were included in the meta-analysis. Pooled sensitivity and specificity were 98.7% (range 98.1-99.2%) and 70.4% (range 68.5-72.2%), respectively. Factors that increased specificity included the use of radiotracers with high hepatic extraction, administration of hepatic-inducing drugs (such as phenobarbital), use of a calculated dose/kg and administration of a booster dose in cases of non-excretion of the tracer in the bowel. SPECT imaging and duodenal fluid sampling also had high specificity; however, they need further validation because of the low number of studies. Semiquantitative imaging methods do not seem to have any incremental value. We conclude that hepatobiliary scintigraphy using IDA derivatives can be very useful for diagnostic work-up of neonatal cholestasis. To improve the specificity, several measures can be followed regarding type and dose of the radiotracer and imaging protocols. Non-imaging methods seem to be promising and warrant further validation.

The diagnostic value of high-frequency ultrasonography in biliary atresia

BACKGROUND

It is a globally challenging problem to differentially diagnose biliary atresia (BA) from other disease processes causing infantile cholestatic jaundice. The high-frequency ultrasonography (HUS) yields much improved spatial resolution and therefore, might show better image in BA diagnostic examination. The present study was to evaluate the HUS on the diagnosis of BA in infants with jaundice.

METHODS

Fifty-one infants with neonatal jaundice were scanned with ultrasonography. Images included gallbladder, bile duct, right hepatic artery (RHA), portal vein (PV) and triangular cord (TC) sign, magnetic resonance imaging and additionally, laboratory tests and histopathology reports were assessed.

RESULTS

Twenty-three BA and 28 non-BA cases were confirmed. The sensitivity, specificity, and accuracy of HUS were 91.3%, 92.9%, and 92.2%, respectively. All of these indices were significantly higher than those of conventional ultrasonography (P<0.01) and MR cholangiopancreatography (P<0.05). The HUS features, included a positive TC sign, an increased RHA diameter and RHA-diameter to portal-vein-diameter ratio (RHA/PV) and abnormal gallbladder, were important in the diagnosis of BA.

CONCLUSION

HUS provided better imaging of BA and should be considered as a primary modality in the differential diagnosis of infantile jaundice.

Analysis of clinical parameters that contribute to the misdiagnosis of biliary atresia

BACKGROUND

Biliary atresia (BA) is one of the most common and perplexing causes of neonatal cholestasis. Each year many cases of neonatal cholestasis are misdiagnosed as BA, resulting in unnecessary exploratory surgery. Therefore, the aim of our study was to analyze the clinical features and parameters that contribute to the misdiagnosis of BA. We used a retrospective study to compare BA and similar neonatal cholestatic diseases, which were confirmed by intraoperative cholangiography.

METHODS

Six hundred and two infants that were suspected to have BA were recruited for the study. All cases were divided into a non-BA group and a BA group according to intraoperative cholangiography. In addition, each group was divided into three subgroups according to the patients age at surgery (group i, < 60 d; group ii, 60-90 d; and group iii > 90 d). The annual misdiagnosis rate of non-BA patients was calculated. Age at onset of jaundice and the liver function and ultrasound results were compared between the two groups and subgroups. Moreover, the positive predictive value and false positive rate of hepatobiliary scintigraphy in the diagnosis of BA were calculated. Finally, the disease spectrum of the non-BA group was analyzed.

RESULTS

Of the 602 cases, 83 patients were diagnosed as non-BA. The remaining 519 cases were confirmed to have BA. There was no significant decline in the misdiagnosis rate of suspected BA cases by year. The age at onset of jaundice, total bilirubin (TBIL), direct bilirubin (DBIL), DBIL/TBIL and alanine aminotransferase (ALT) values before the exploratory operation showed no statistically significant difference (P > 0.05) in the non-BA versus BA groups. However, the mean level of gamma-glutamyl transpeptidase (γ-GT) was 263.2 mmol/l in the non-BA group and 902.7 mmol/l in the BA group (P < 0.01). The length of the liver below the ribs was detected with ultrasound and found to be smaller in the non-BA group than that of the BA group (2.99 cm ± 1.62 vs. 3.61 cm ± 1.26, respectively; P < 0.05). Among the 498 infants who received hepatobiliary scintigraphy examination, the false positive rate was 13.3% (66/498) and the positive predictive value was 86.7% (432/498). In the non-BA group, 58 infants suffered from hepatitis syndrome, 16 cases were biliary dysplasia, 5 cases were TPN related cholestasis, 2 cases were bile duct perforation and 2 were bile-plug syndrome.

CONCLUSION

The similarity of liver function tests and excessive dependence on hepatobiliary scintigraphy may contribute to the misdiagnosis of infants with jaundice. The age at onset of jaundice, the level of γ-GT and the liver length below the ribs may be helpful in the differential diagnosis of jaundice in infants.

Fetal MRI: An approach to practice: A review

MRI has been increasingly used for detailed visualization of the fetus in utero as well as pregnancy structures. Yet, the familiarity of radiologists and clinicians with fetal MRI is still limited. This article provides a practical approach to fetal MR imaging. Fetal MRI is an interactive scanning of the moving fetus owed to the use of fast sequences. Single-shot fast spin-echo (SSFSE) T2-weighted imaging is a standard sequence. T1-weighted sequences are primarily used to demonstrate fat, calcification and hemorrhage. Balanced steady-state free-precession (SSFP), are beneficial in demonstrating fetal structures as the heart and vessels. Diffusion weighted imaging (DWI), MR spectroscopy (MRS), and diffusion tensor imaging (DTI) have potential applications in fetal imaging. Knowing the developing fetal MR anatomy is essential to detect abnormalities. MR evaluation of the developing fetal brain should include recognition of the multilayered-appearance of the cerebral parenchyma, knowledge of the timing of sulci appearance, myelination and changes in ventricular size. With advanced gestation, fetal organs as lungs and kidneys show significant changes in volume and T2-signal. Through a systematic approach, the normal anatomy of the developing fetus is shown to contrast with a wide spectrum of fetal disorders. The abnormalities displayed are graded in severity from simple common lesions to more complex rare cases. Complete fetal MRI is fulfilled by careful evaluation of the placenta, umbilical cord and amniotic cavity. Accurate interpretation of fetal MRI can provide valuable information that helps prenatal counseling, facilitate management decisions, guide therapy, and support research studies.

Predictive Value of Assessment of Different Modalities in the Diagnosis of Infantile Cholestasis

This study investigated the relative accuracy and roles of abdominal ultrasonography, hepatobiliary scintigraphy and liver biopsy in the diagnosis of infantile cholestasis. A total of 50 infants (27 females) aged 1 − 12 months were classified into those with intrahepatic causes of cholestasis ( n = 22) and those with extrahepatic causes ( n = 28). Cholestasis is caused by a wide range of conditions and diagnosis requires meticulous history taking, thorough clinical examination and many laboratory tests. The most common cause of intrahepatic cholestasis was found to be idiopathic neonatal hepatitis (54.5%), followed by infectious hepatitis (9.1%), metabolic liver diseases (9.1%), intrahepatic biliary atresia (9.1%) and Alagille syndrome (4.5%). The most common cause of extrahepatic cholestasis was extrahepatic biliary atresia (96.4%). The incidence of choledochal cyst was low (3.6%). The cornerstone of the diagnosis of infantile cholestasis was found to be liver biopsy, which was associated with a high degree of accuracy.

Endoscopic retrograde cholangiopancreaticography prior to explorative laparotomy avoids unnecessary surgery in patients suspected for biliary atresia

BACKGROUND/AIMS

Timely diagnosis of biliary atresia (BA) requires key investigations that are less invasive but as accurate as possible. Non-invasive imaging preselects patients before explorative laparotomy is performed. The purpose of this prospective study was to evaluate the accuracy of endoscopic retrograde cholangiopancreaticography (ERCP) in these patients and to discuss its relevance to future diagnostic guidelines in neonatal jaundice.

METHODS

Over a 7-year period, ERCP was routinely performed in cholestatic patients less than 6 months of age suspected for an extrahepatic origin of cholestasis, most likely BA. Endoscopic diagnosis was correlated with intraoperative findings.

RESULTS

In 140 consecutive patients (mean age: 60 days; weight: 4 kg), ERCP excluded BA in 34 (25%) but failed in 18 newborns (13%) for technical reasons. The average procedure time was 23 min, and no severe complications occurred. Explorative laparotomy was performed in 106 patients and revealed BA in 80 cases. In this series, the sensitivity of ERCP for diagnosing biliary atresia was 92% and specificity was 73%.

CONCLUSIONS

In preselected patients, ERCP is not an alternative to non-invasive imaging, but it avoids unnecessary surgical procedures in almost 25% of the cases. Hence, ERCP is recommended prior to explorative laparotomy in all patients suspected for BA.

Diffuse liver diseases in neonatal and pediatric liver transplant candidates: a pictorial essay

A wide spectrum of common and uncommon diffuse liver diseases affecting neonatal and pediatric liver transplant candidates is presented and analyzed using 16 and 64 multi-detector row helical CT (MDCT) and 1.5 T MRI fast imaging. Correlation of imaging findings and explanted liver or histology is illustrated in representative cases. Associated uncommon congenital anomalies are shown. In conclusion, in pediatric liver transplant candidates, 16-MDCT and 1.5 T fast MRI are useful for diagnosis and staging of liver disease, as well as for the evaluation of associated congenital anomalies.

Biliary atresia: color doppler US findings in neonates and infants

PURPOSE

To describe color Doppler ultrasonographic (US) findings in livers of neonates with biliary atresia (BA) and to compare them with US findings in livers of neonates with non-BA and control subjects.

MATERIALS AND METHODS

Institutional review board approval was obtained; acquisition of informed consent was exempted. US and color Doppler US findings were retrospectively reviewed in 64 patients with neonatal cholestasis and 19 control subjects. BA and non-BA were confirmed in 29 and 35 patients, respectively. Three pediatric radiologists assessed US and color Doppler US images, independently documented their findings, and resolved discrepancies by consensus. Triangular cord (TC) sign, gallbladder length, and hepatic artery and portal vein diameters were evaluated on US images. The presence of hepatic subcapsular flow was evaluated on color Doppler US images. Diagnostic value of TC sign and hepatic subcapsular flow in the diagnosis of BA were evaluated. Significance of hepatic artery and portal vein diameters in each group was assessed.

RESULTS

In the diagnosis of BA, sensitivity and specificity of the TC sign on US images were 62% and 100%, respectively. On color Doppler US images, hepatic subcapsular flow was detected in all patients with BA and in five patients with non-BA. At the first review, there was a discrepancy between radiologists in interpretation of hepatic subcapsular flow in patients with non-BA. However, consensus was reached at the second review. There was no hepatic subcapsular flow in control subjects. Sensitivity and specificity of hepatic subcapsular flow on color Doppler US images were 100% and 80%-86%, respectively, on the basis of individual interpretations of reviewers. Sensitivity and specificity of hepatic subcapsular flow on color Doppler US images were 100% and 86%, respectively, on the basis of consensus reading. Mean diameter of the hepatic artery in patients with BA (2.1 mm +/- 0.7 [standard deviation]) was significantly larger than that in patients with non-BA (1.5 mm +/- 0.4, P < .001) and control subjects (1.5 mm +/- 0.4, P = .001).

CONCLUSION

The presence of hepatic subcapsular flow is useful for differentiating between BA and other causes of neonatal jaundice.

Ultrasonic diagnosis of biliary atresia: A retrospective analysis of 20 patients

AIM: To investigate the clinical value of ultrasonographic diagnosis of biliary atresia (BA), a retrospective analysis of the sonogram of 20 children with BA was undertaken.

METHODS: Ultrasonography (US) was performed in 20 neonates and infants with BA, which was confirmed with cholangiography by operation or abdominoscopy. The presence of triangular cord, the size and echo of liver, the changes in empty stomach gallbladder and postprandial gallbladder were observed and recorded.

RESULTS: The triangular cord could be observed at the porta hepatis (thickness: 0.3-0.6 cm) in 10 cases. Smaller triangular cord (0.2-0.26 cm) can be observed in 3 cases. The gallbladder was not observed in 2 cases, and 1 case showed a streak gallbladder without capsular space. The gallbladders of 15 cases were flat and small. The gallbladders of 2 cases were of normal size and appearance, however, there was no postprandial contraction. The livers of all cases showed hepatomegaly and heterogeneous echogenicity. Statistical analysis was performed to compare the hepatomegaly and heterogeneous echogenicity and the stage of hepatic fibrosis.

CONCLUSION: The presence of the triangular cord at the porta hepatis is specific. However, it is not the only diagnostic criterion, since flat and small gallbladder and poor contraction are also of important diagnostic and differential diagnostic significance. The degree of hepatomegaly and heterogeneous echogenicity is proportional with liver fibrosis, and able to indicate the duration of course and prognosis.

Hepatic arterial diameter measured with US: adjunct for US diagnosis of biliary atresia

PURPOSE

To prospectively evaluate the accuracy of hepatic artery diameter and hepatic artery diameter-to-portal vein diameter ratio for ultrasonographic (US) diagnosis of biliary atresia, with cholangiographic or clinical information as reference standard.

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. US was performed in 68 neonates and infants with cholestatic jaundice (mean age, 61 days; male-to-female ratio, 38:30). Biliary atresia (n = 38) was confirmed with cholangiography, and hepatitis (n = 30) was diagnosed with clinical (n = 24) or cholangiographic (n = 6) findings. Diameter of the right hepatic artery was measured with US. Right hepatic artery diameter-to-right portal vein diameter ratio was measured to determine relative enlargement of the hepatic artery. As a control group, 17 neonates and infants (mean age, 67 days; male-to-female ratio, 12:5) without jaundice underwent US of the porta hepatis. Statistical analysis was performed to compare US parameters among three groups with one-way analysis of variance. Optimal cutoff values of the hepatic artery diameter and hepatic artery diameter-to-portal vein diameter ratio for biliary atresia diagnosis were obtained with receiver operating characteristic analysis.

RESULTS

The diameter of the right hepatic artery in biliary atresia group (1.9 mm +/- 0.4 [standard deviation]) was significantly larger than that in the hepatitis (1.4 mm +/- 0.3) and control (1.2 mm +/- 0.2) groups (P < .001). Hepatic artery diameter-to-portal vein diameter ratio in the biliary atresia group (0.52 +/- 0.12) was larger than that in hepatitis (0.40 +/- 0.07) and in control (0.40 +/- 0.10) groups (P < .001). Optimum cutoff values for diagnosis of biliary atresia were 1.5 mm (sensitivity, 92%; specificity, 87%; accuracy, 89%) for hepatic artery diameter and 0.45 for hepatic artery diameter-to-portal vein diameter ratio (sensitivity, 76%; specificity, 79%; accuracy, 78%).

CONCLUSION

Measurement of hepatic artery diameter can be helpful in the US diagnosis of biliary atresia.

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MR Imaging of the Gallbladder and Biliary System

MR imaging is an established technique for the diagnosis of a spectrum of biliary and gallbladder pathologies and continues to improve with the advent of technologic advances, including new contrast agents and new sequences that are capable of improving upon the contrast resolution and signal-to-noise that are afforded by conventional MR imaging. These improvements already have shown promise for the increasing role of MRC as the initial modality in assessing living liver donors and evaluating post-operative hepato-biliary complications. Improved spatial resolution and the added functional or physiologic information afforded by MR imaging promise ever expanding clinical applicability and usefulness.

Guideline for the evaluation of cholestatic jaundice in infants: recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition

For the primary care provider, cholestatic jaundice in infancy, defined as jaundice caused by an elevated conjugated bilirubin, is an uncommon but potentially serious problem that indicates hepatobiliary dysfunction. Early detection of cholestatic jaundice by the primary care physician and timely, accurate diagnosis by the pediatric gastroenterologist are important for successful treatment and a favorable prognosis. The Cholestasis Guideline Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition has formulated a clinical practice guideline for the diagnostic evaluation of cholestatic jaundice in the infant. The Cholestasis Guideline Committee, consisting of a primary care pediatrician, a clinical epidemiologist (who also practices primary care pediatrics), and five pediatric gastroenterologists, based its recommendations on a comprehensive and systematic review of the medical literature integrated with expert opinion. Consensus was achieved through the Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests commonly used for the evaluation of cholestatic jaundice and how those interventions can be applied to clinical situations in the infant. The guideline provides recommendations for management by the primary care provider, indications for consultation by a pediatric gastroenterologist, and recommendations for management by the pediatric gastroenterologist. The Cholestasis Guideline Committee recommends that any infant noted to be jaundiced at 2 weeks of age be evaluated for cholestasis with measurement of total and direct serum bilirubin. However, breast-fed infants who can be reliably monitored and who have an otherwise normal history (no dark urine or light stools) and physical examination may be asked to return at 3 weeks of age and, if jaundice persists, have measurement of total and direct serum bilirubin at that time. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition on the evaluation of cholestatic jaundice in infants. The American Academy of Pediatrics has also endorsed these recommendations. These recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the care of all patients with this problem.

[Biliary atresia: Retrospective clinical study]

OBJECTIVE

To gain further insight into the natural history of patients with biliary atresia.

PATIENTS AND METHODS

We performed a retrospective, cross-sectional, descriptive, case series study. All patients with biliary atresia attended at the Pediatric Gastrointestinal and Hepatology Unit of La Fe Children's Hospital in Valencia (Spain) from January 1990 to December 2000 were included.

RESULTS

Of 16 children followed-up, eight are currently stable, six have undergone liver transplantation and two died. The mean age at diagnosis was 47.5 days. The most frequent clinical manifestation was jaundice (87.5%) and the most common biochemical finding was raised gamma-glutamyltransferase (3-4 times its standard value), which appeared in 100 % of the patients. Abdominal ultrasonography was diagnostic in 85.7% of the patients. Nuclear scintiscan (DISIDA) showed a sensitivity of 100%. Portoenterostomy with intraoperative liver biopsy was performed in all patients. Patient age at surgery was a predictor of long-term outcome, with more favorable results in patients aged less than 65 days of life.

CONCLUSIONS

Biliary atresia should be suspected as soon as possible, since early surgical treatment is the only therapeutic measure that can improve outcome.

Biliary atresia: making the diagnosis by the gallbladder ghost triad

OBJECTIVE

To describe the gallbladder ghost triad and evaluate its usefulness in the sonographic diagnosis of extrahepatic biliary atresia (BA).

METHODS

From October 1997 to February 2002, 217 fasted infants with cholestatic jaundice aged 2-12 weeks were examined sonographically. We defined the gallbladder ghost triad as gallbladder length <1.9 cm, lack of smooth/complete echogenic mucosal lining with an indistinct wall and irregular/lobular contour, and used it as a criteria for BA. Gallbladder wall thickness, triangular cord, diffuse periportal echogenicity and hepatic artery calibre were also recorded. Diagnosis of BA was confirmed surgically and histologically.

RESULTS

Thirty of 31 babies with BA demonstrated the gallbladder ghost triad. No false-positives were recorded. The 31st BA baby showed a normal gallbladder at 6 weeks, but developed the ghost triad at 8 weeks. Gallbladder wall thickening was seen in 46/186 non-BA babies, but not in BA. Triangular cord was observed in 24/31 babies. Twenty-two of 186 non-BA babies and 5/31 BA babies showed diffuse periportal echogenicity. The hepatic artery appeared more prominent in BA. All 31 babies diagnosed sonographically as BA had surgery. Three non-BA babies had "negative" laparotomies showing hypoplastic bile ducts.

CONCLUSIONS

The gallbladder ghost triad is a very accurate sign of BA. Indeterminate cases require close follow-up.

The neonatal liver part II: Assessment and diagnosis of liver dysfunction

The liver, the largest organ in the body, performs many essential functions, including the storage and filtration of blood, production of bile, regulation of plasma proteins and glucose, and biotransformation of drugs and toxins. Many neonates display signs of hepatic dysfunction such as hyperbilirubinemia, hepatomegaly, or elevated liver enzymes. Primary liver disease in neonates is rare; much of the liver dysfunction seen in the neonatal period is secondary to systemic illness such as sepsis or hypoxic injury. It is important for the clinician to have the skills and knowledge necessary to distinguish intrinsic liver disease from liver dysfunction resulting from extrahepatic causes. Early intervention to address the cause of dysfunction is critical to successful management of liver disease. This article reviews the assessment of liver function in neonates and examines the techniques used to diagnose liver dysfunction.

Pancreas and biliary system: imaging of developmental anomalies and diseases unique to children

The focus of this article is on the development of the pancreas and biliary system, with a review of the most common congenital anomalies affecting the pancreas and biliary tree, including pancreas divisum, annular pancreas, congenital shortening of the pancreas, and choledochal cysts. Additionally, biliary atresia and pancreatoblastoma--both diseases of the pancreas and biliary system that almost exclusively affect children--are considered, with a discussion regarding the clinical presentation and imaging appearances of these disorders.

Magnetic resonance cholangiography for the diagnosis of biliary atresia

PURPOSE

The aim of this study was to evaluate the usefulness of magnetic resonance cholangiography (MRC) for the diagnosis of biliary atresia in infantile cholestatic jaundice.

METHODS

Forty-seven consecutive infants with cholestatic jaundice underwent single-shot MRC. The diagnosis of biliary atresia was made by MRC based on the nonvisualization of extrahepatic bile ducts and excluded on the basis of the complete visualization of extrahepatic bile ducts. The final diagnosis of biliary atresia (BA group, n = 23) or nonbiliary atresia (NBA group, n = 24) was established by operation or clinical follow-up until the jaundice resolved.

RESULTS

The extrahepatic bile ducts including the gallbladder, the cystic duct, the common bile duct, and the common hepatic duct were visualized in 23 of the 24 infants of the NBA group. The extrahepatic bile ducts, except the gallbladder, were not depicted in any infant of the BA group. MRC had an accuracy of 98%, sensitivity of 100% and specificity of 96%, for diagnosis of biliary atresia as the cause of infantile cholestatic jaundice.

CONCLUSIONS

MRC is a very reliable noninvasive imaging modality for the diagnosis of biliary atresia. In infants with cholestatic jaundice and considered for exploratory laparotomy, MRC is recommended to avoid unnecessary surgery.

Unique imaging issues in pediatric liver disease

In many clinical scenarios, liver imaging does not differ as greatly in children as in adults. Common indications for liver imaging in children include trauma, suspected mass, pre-transplantation studies, monitoring after liver transplantation, jaundice, or liver dysfunction. This article highlights areas in which pathology or imaging approach in children differs from that seen in adults. Topics covered include imaging of a suspected hepatic mass, neonatal jaundice, and segmental liver transplantation.