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

[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.

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.

Diffuse Versus Localized Caroli Disease: A Comparative MRCP Study

OBJECTIVE. The purpose of this multicenter retrospective study was to assess the MRCP features of Caroli disease (CD). MATERIALS AND METHODS. Sixty-six patients were identified from 2000 to 2019. The inclusion criteria were diagnosis of diffuse or localized CD mentioned in an imaging report, presence of intrahepatic bile duct (IHBD) dilatation, and having undergone an MRCP examination. The exclusion criteria included presence of obstructive proximal biliary stricture and having undergone hepatobiliary surgery other than cholecystectomy. Histopathology records were available for 53 of the 66 (80%) patients. Diffuse and localized diseases were compared by chi-square and t tests and Kaplan-Meier model. RESULTS. Forty-five patients had diffuse bilobar CD ((five pediatric patients [three girls and two boys] with a mean [± SD] age of 8 ± 5 years [range, 1-15 years] and 40 adult patients [26 men and 14 women] with a mean age of 35 ± 11 years [range, 20-62 years]) and 21 patients had localized disease (12 men and 9 women; mean age, 54 ± 14 years). Congenital hepatic fibrosis was found only in patients with diffuse CD (35/45 [78%]), as was a "central dot" sign (15/35 [43%]). IHBD dilatation with both saccular and fusiform features was found in 43 (96%) and the peripheral "funnel-shaped" sign in 41 (91%) of the 45 patients with diffuse CD but in none of the patients with localized disease (p < .001). Intrahepatic biliary calculi were found in all patients with localized disease but in only 16 of the 45 (36%) patients with diffuse CD (p < .001). Left liver atrophy was found in 18 of the 21 (86%) patients with localized disease and in none of the patients with diffuse CD (p < .001). The overall survival rate among patients with diffuse CD was significantly lower than that among patients with localized disease (p = .03). CONCLUSION. Diffuse IHBD dilatation with both saccular and fusiform features associated with the peripheral funnel-shaped sign can be used for the diagnosis of CD on MRCP. Localized IHBD dilatation seems to be mainly related to primary intrahepatic lithiasis.

Non-pharmacological strategies to obtain usable magnetic resonance images in non-sedated infants: Systematic review and meta-analysis

BACKGROUND

Although the use of sedation is commonly practiced to keep infants still while receiving magnetic resonance imaging, non-pharmacological strategies are a potential alternative.

OBJECTIVES

The purpose of this study was to determine the success rate of obtaining usable magnetic resonance images in infants with the sole use of non-pharmacological strategies.

DESIGN

Systematic literature review and meta-analysis SETTING: A search was conducted in PubMed, CINAHL and Cochrane Library.

PARTICIPANTS

Human infants from birth to 24 months of age who did not receive any sedation or anesthesia during magnetic resonance imaging METHOD: Articles that reported the success rate of obtaining usable images were included.

RESULTS

Of the 521 non-duplicate articles found, 58 articles were included in the systematic review with sample sizes ranging from 2-457, an average success rate of 87.8%, and an average scan time of 30 min. The most common non-pharmacological technique included feeding and swaddling infants before imaging to encourage infants to sleep during the scan. Meta-analysis performed on 53 articles comprising 3,410 infants found a success rate of 87%, but significant heterogeneity was found (I² = 98.30%). It was more difficult to obtain usable images solely with non-pharmacological techniques if infants were critically ill or a structural magnetic resonance imaging of the brain was required.

CONCLUSION

Non-pharmacological techniques are effective for obtaining usable magnetic resonance imaging scans in most but not all infants. Tweetable abstract: Non-pharmacological techniques are effective for obtaining usable magnetic resonance imaging scans in most infants.

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.

Imaging findings of Alagille syndrome in young infants: differentiation from biliary atresia

OBJECTIVE

To compare the imaging findings using ultrasonography, MR cholangiopancreatography (MRCP), and intraoperative cholangiography (IOC) between Alagille syndrome (AGS) and biliary atresia (BA) in young infants with cholestatic jaundice.

METHODS

The institutional review board approved this retrospective study. Ultrasonography (n = 55), MRCP (n = 33), and IOC (n = 22) studies were performed in 55 infants (all younger than 3 months) with AGS (n = 7) and BA (n = 48). The ultrasound images were reviewed focusing on gallbladder (GB) abnormalities, triangular cord sign, hepatic artery enlargement and signs of portal hypertension. Visualization of the extrahepatic biliary tree was assessed by MRCP and IOC.

RESULTS

Six (86%) AGS patients showed a small GB on ultrasound; this was comparable to that in BA patients (81%, 35/43). The images were negative for triangular cord sign and hepatic artery enlargement in all AGS patients, whereas they were positive in 48% (23/48) (p = 0.034) and 77% (33/43) (p < 0.001) of the BA patients, respectively. Signs of portal hypertension were less common in AGS patients than in BA patients (p = 0.010). Although non-visualization of the extrahepatic biliary tree by MRCP did not differ significantly between patients with AGS and BA, AGS patients showed a higher proportion of visible common bile ducts with IOC, compared to BA patients. The diagnosis of AGS was made in four infants (57%) before ultrasonography, based on extrahepatic manifestations.

CONCLUSION

The small GB visualized on ultrasonography and non-visualization of extrahepatic biliary tree by MRCP commonly occurred in patients with either AGS or BA. However, triangular cord sign, hepatic artery enlargement and signs of portal hypertension onultrasonography and non-visualized common bile duct with IOC were less frequent in AGS patients than in BA patients. Advances in knowledge: Atypical imaging findings for BA should prompt a meticulous evaluation for the extrahepatic manifestations of AGS to avoid possibly harmful surgery.

Paediatric Gastrointestinal Endoscopy: European Society for Paediatric Gastroenterology Hepatology and Nutrition and European Society of Gastrointestinal Endoscopy Guidelines

This guideline refers to infants, children, and adolescents ages 0 to 18 years. The areas covered include indications for diagnostic and therapeutic esophagogastroduodenoscopy and ileocolonoscopy; endoscopy for foreign body ingestion; corrosive ingestion and stricture/stenosis endoscopic management; upper and lower gastrointestinal bleeding; endoscopic retrograde cholangiopancreatography; and endoscopic ultrasonography. Percutaneous endoscopic gastrostomy and endoscopy specific to inflammatory bowel disease has been dealt with in other guidelines and are therefore not mentioned in this guideline. Training and ongoing skill maintenance are to be dealt with in an imminent sister publication to this.

Incremental Value of MR Cholangiopancreatography in Diagnosis of Biliary Atresia

Purpose

To evaluate the incremental value of a combination of magnetic resonance cholangiopancreatography (MRCP) and ultrasonography (US), compared to US alone, for diagnosing biliary atresia (BA) in neonates and young infants with cholestasis.

Materials and Methods

The institutional review board approved this retrospective study. The US and MRCP studies were both performed on 64 neonates and young infants with BA (n = 41) or without BA (non-BA) (n = 23). Two observers reviewed independently the US alone set and the combined US and MRCP set, and graded them using a five-point scale. Diagnostic performance was compared using pairwise comparison of the receiver operating characteristics (ROC) curve. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value were assessed.

Results

The diagnostic performance (the area under the ROC curve [A_z]) for diagnosing BA improved significantly after additional review of MRCP images; A_z improved from 0.688 to 0.901 (P = .015) for observer 1 and from 0.676 to 0.901 (P = .011) for observer 2. The accuracy of MRCP combined with US (observer 1, 95% [61/64]; observer 2 92% [59/64]) and PPV (observer 1, 95% [40/42]; observer 2 91% [40/44]) were significantly higher than those of US alone for both observers (accuracy: observer 1, 73% [47/64], P = 0.003; observer 2, 72% [46/64], P = 0.004; PPV: observer 1, 76% [35/46], P = 0.016; observer 2, 76% [34/45], P = 0.013). Interobserver agreement of confidence levels was good for US alone (ĸ = 0.658, P < .001) and was excellent for the combined set of US and MRCP (ĸ = 0.929, P < .001).

Conclusion

Better diagnostic performance was achieved with the combination of US and MRCP than with US alone for the evaluation of BA in neonates and young infants with cholestasis.

Biliary atresia: Clinical advances and perspectives

Biliary atresia (BA) is a rare and severe inflammatory and obliterative cholangiopathy that affects both extra- and intrahepatic bile ducts. BA symptoms occur shortly after birth with jaundice, pale stools and dark urines. The prognosis of BA has dramatically changed in the last decades: before the Kasai operation most BA patients died, while nowadays with the sequential treatment with Kasai operation±liver transplantation BA patient survival is close to 90%. Early diagnosis is very important since the chances of success of the Kasai procedure decrease with time. The causes of BA remain actually unknown but several mechanisms including genetic and immune dysregulation may probably lead to the obliterative cholangiopathy. Current research focuses on the identification of blood or liver factors linked to the pathogenesis of BA that could become therapeutic targets and avoid the need for liver transplantation. No similar disease leading to total obstruction of the biliary tree exists in older children or adults. But understanding the physiopathology of BA may highlight the mechanisms of other destructive cholangiopathies, such as sclerosing cholangitis.

Factors Interfering with Delineation on MRCP of Pancreaticobiliary Maljunction in Paediatric Patients

Background

The aim of this study was to assess factors for delineating the pancreaticobiliary junction in the presence of pediatric congenital choledochal cysts (CCC) using Magnetic resonance cholangiopancreatography (MRCP).

Methods

Retrospective review of medical records for 48 patients with CCC was conducted, including demographics, biliary amylase and MRCP findings if available. With univariate and multivariate logistic regression, we measured significant factors affecting pancreaticobiliary maljunction(PBM) diagnoses by MRCP.

Results

Of the subjects enrolled with CCC. Twenty-eight cases had PBM according to MRCP. Univariate analysis confirmed that age, cyst diameter > 30 mm and cysts that descended to the introitus pelvis affected junctional delineation and detection of PBM (P<0.05). Stepwise logistic regression analysis confirmed large cysts in the introitus pelvis predicted pancreaticobiliary junctional delineation in MRCP and these data agreed with the literature. A correlation between cyst diameter and the length of the common channel was found as was cyst diameter and biliary amylase although there were no significant differences between them.

Conclusions

Age, cyst diameter >30 mm and descending cysts into the introitus pelvis affected junctional delineation of the pancreatic and bile duct in PBM with MRCP. Large cyst descension into the introitus pelvis was an independent factors affecting PBM detection.

Conjoined twins: Radiological experience

Imaging plays a key role in the management of conjoined twins. Pre-operative multi-modality studies are vital to assess operability and to aid surgical planning. Technical advances in imaging such as high-resolution isovolumetric magnetic resonance imaging (MRI) techniques and three-dimensional modeling now result in extremely accurate anatomical information. Varied information from a comprehensive radiological work-up enables the surgeons to plan the safest possible operative procedure, helps the anesthetic team before and during surgery, and guides the intensive care team in the post-operative phase. This article will review the radiological techniques used in our institution, highlighting potential pitfalls with the various imaging modalities.