Imaging of Pancreaticobiliary Maljunction

Utility of Contrast-Enhanced Harmonic Endoscopic Ultrasonography to Diagnose Pancreaticobiliary Maljunction

BACKGROUND

Detection of a common channel outside the duodenal wall is important in diagnosing pancreaticobiliary maljunction (PBM). The present study evaluated the utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) in diagnosing PBM.

METHODS

This single-center retrospective study enrolled 45 patients who were diagnosed with PBM or high confluence of pancreatobiliary ducts (HCPBD) between January 2007 and December 2021. The diagnostic sensitivities of contrast-enhanced computed tomography (CE-CT), magnetic resonance imaging (MRI), and CH-EUS for diagnosing PBM were analyzed. Imaging findings were evaluated by two reviewers blinded to the clinicopathological results.

RESULTS

Based on diagnostic criteria, 33 patients were diagnosed with PBM and 12 with HCPBD. Compared with the patients with HCPBD, those with PBM had significantly longer common channel (12.5 mm vs. 8.1 mm, P = 0.018) and common bile duct (13.0 mm vs. 8.6 mm, P = 0.049) lengths. The κ-coefficients for differentiating PBM and HCPBD were 0.871 between CE-CT and MRI, 0.330 between CE-CT and CH-EUS, and 0.611 between MRI and CH-EUS. The diagnostic sensitivity of CH-EUS (95.2%) was higher than that of CE-CT (83.3%) and MRI (82.8%), although the differences were not statistically significant.

CONCLUSION

CH-EUS may be useful for the diagnosis of PBM.

Percutaneous Ultrasound Cholangiography With Microbubbles in Children With Biliary Diseases

ABSTRACT

The application of intracavity contrast-enhanced ultrasound in the evaluation of biliary disease has been confirmed valuable among pediatric population. This pictorial essay aims to demonstrate the role of percutaneous ultrasound cholangiography (PUSC) with microbubbles in the diagnosis of different pediatric biliary diseases in our center. The biliary system's morphologic characteristics in PUSC mode of neonatal hepatitis, biliary atresia, choledochal cysts, and biliary complications of hepatobiliary surgery are presented.

Recurrent Acute Pancreatitis in the Setting of Abnormal Pancreaticobiliary Junction

Anomalous or abnormal pancreaticobiliary junction (APBJ) is an important structural cause of recurrent acute pancreatitis. Outside of the common causes of recurrent acute pancreatitis, such as alcohol, gallstones, or hypertriglyceridemia, this anatomical variant can often be overlooked and lead to delays in patient care and even mismanagement. It can be defined as the abnormal junction of the pancreatic duct and common bile duct that occurs outside the duodenal wall to form a long common channel (>8 mm). We describe a case of a 51-year-old female with multiple episodes of acute pancreatitis. Further investigation led to the diagnosis of an aberrant pancreatic duct anatomy with the common bile duct measuring around 20 mm. This report will include a discussion about the pancreaticobiliary junction, how it can be diagnosed, and what complications it can precipitate.

A Unique Type or Variation of Bile Duct Cyst in a 9-Year-Old Girl:A Remarkable Case Study

Patients with bile duct cysts require careful radiological assessment of the hepatobiliary system prior to surgical intervention. This clinical case is uncommon with an atypical clinical presentation and radiological findings. According to the most widely used classification of choledochal cysts, this case presents a combination of Type I and Type IV of choledochal cyst (CC) combining the form of extra, intrahepatic bile ducts and cystic duct dilations.

An Unusual Case of Large Cell Neuroendocrine Cancer of the Gallbladder With Mixed Adenocarcinoma Component in a Patient With Pancreatobiliary Maljunction

Gallbladder neuroendocrine tumors (GB-NETs) and gallbladder neuroendocrine carcinomas (GB-NECs) are rare forms of neuroendocrine neoplasms (NENs). Most GB-NENs present as incidental findings or as gallbladder polyps in the course of investigation of nonspecific symptoms such as upper abdominal pain and nausea. Given the rarity of GB-NENs, only a few small case series are currently available describing this entity, and even fewer guiding consensus on standard treatment and the role of adjuvant therapy.  We present the case of a 65-year-old South American female referred for a chronic history of intermittent post-prandial epigastric pain, bloating, nausea, and occasional diarrhea. Pancreaticobiliary maljunction with dilation was present and she was diagnosed with primary gallbladder large cell neuroendocrine carcinoma (GB-LCNEC) mixed with a minor component of gallbladder adenocarcinoma.

Development of a simplified model and nomogram in preoperative diagnosis of pediatric chronic cholangitis with pancreaticobiliary maljunction using clinical variables and MRI radiomics

OBJECTIVE

The aim of this study was to develop a model that combines clinically relevant features with radiomics signature based on magnetic-resonance imaging (MRI) for diagnosis of chronic cholangitis in pancreaticobiliary maljunction (PBM) children.

METHODS

A total of 144 subjects from two institutions confirmed PBM were included in this study. Clinical characteristics and MRI features were evaluated to build a clinical model. Radiomics features were extracted from the region of interest manually delineated on T2-weighted imaging. A radiomics signature was developed by the selected radiomics features using the least absolute shrinkage and selection operator and then a radiomics score (Rad-score) was calculated. We constructed a combined model incorporating clinical factors and Rad-score by multivariate logistic regression analysis. The combined model was visualized as a radiomics nomogram to achieve model visualization and provide clinical utility. Receiver operating curve analysis and decision curve analysis (DCA) were used to evaluate the diagnostic performance.

RESULTS

Jaundice, protein plug, and ascites were selected as key clinical variables. Eight radiomics features were combined to construct the radiomics signature. The combined model showed superior predictive performance compared with the clinical model alone (AUC in the training cohort: 0.891 vs. 0.767, the validation cohort: 0.858 vs. 0.731), and the difference was significant (p = 0.002, 0.028) in the both cohorts. DCA confirmed the clinical utility of the radiomics nomogram.

CONCLUSION

The proposed model that combines key clinical variables and radiomics signature is helpful in the diagnosis of chronic cholangitis in PBM children.

Imaging of the biliary tract

PURPOSE OF REVIEW

Magnetic resonance cholangiopancreatography (MRCP) has become the reference examination for the exploration of the biliary tract and has replaced endoscopic cholangiography for the analysis of the biliary tract because of its equivalent performance and its noninvasive character.

RECENT FINDINGS

Based on the International Primary Sclerosing Cholangitis (PSC) Study Group recommendations for MR imaging in PSC, two protocols can be distinguished for the imaging of biliary tract: a basic protocol and a more complete protocol. It is essential to know the main pitfalls in order not to wrongly describe biliary anomalies. In addition to the excellent performance of MR imaging with MRCP in analyzing the anatomy and the anomalies of the biliary tree, complementary techniques have recently been developed. Several MR prognostic factors have been described. New hepato-specific contrast agents are now available for assessment of the general and segmental liver function. MR Elastography and Diffusion-weighted MR sequences are accurate to evaluate the degree of hepatic fibrosis. Finally, images obtained in MRCP can be postprocessed by a software that will analyze and model the biliary tree in order to quantitatively evaluate the biliary system.

SUMMARY

Magnetic resonance imaging with its recent developments becomes by now an essential tool for the evaluation of biliary diseases.

Risk Factors Associated with Acute Pancreatitis after Percutaneous Biliary Intervention: We Do Not Know Nearly Enough

Percutaneous transhepatic cholangiodrainage (PTCD) and percutaneous transhepatic biliary stenting (PTBS) may be used as a palliative treatment for inoperable patients with malignant biliary obstruction (MBO) to improve the prognosis and their quality of life. However, acute pancreatitis is a common and severe complication that cannot be ignored after PTCD and PTBS in patients with MBO. A few cases may develop severe pancreatitis with a higher mortality rate. In this study, we summarize the known risk factors for acute pancreatitis after percutaneous biliary interventional procedures and investigate possible risk factors to reduce its occurrence by early identifying high-risk patients and taking appropriate measures.

Imaging of benign biliary pathologies

Pathologies of the biliary tree include a wide-spectrum of benign and malignant processes. The differential for benign disease includes congenital and acquired disease with variable prognosis and management pathways. Given the ability to mimic malignancy, benign processes are difficult to diagnose by imaging. Direct cholangiography techniques with tissue sampling are the gold standards for the diagnosis of benign and malignant biliary pathologies. Non-invasive imaging with ultrasound offers a first-line diagnostic tool while MRI/MRCP offers higher specificity for identifying underlying pathology and distinguishing from malignant disease. In this review, we focus on the imaging appearance of dilatation, cystic anomalies obstruction, inflammation, ischemia, strictures, pneumobilia, and hemobilia to help construct a differential for benign processes.

Surgery

This chapter provides a comprehensive background from basic to applied knowledge of surgical anatomy which is necessary for the surgical treatment of cholangiocarcinoma (CCA) patients. Significant advances that have been made in the surgical treatment of CCA were examined. For instance, in-depth details are provided for appropriate preoperative assessment and treatment to optimize patient status and to improve the outcome of surgical treatment(s). Comprehensive details are provided for the surgical techniques and outcomes of treatments for each type of CCA with clear illustrations and images. This chapter also describes the role of minimally invasive surgery and liver transplantation in CCA treatment.

Imaging Features of Premalignant Biliary Lesions and Predisposing Conditions with Pathologic Correlation

Biliary malignancies include those arising from the intrahepatic and extrahepatic bile ducts as well as the gallbladder and hepatopancreatic ampulla of Vater. The majority of intrahepatic and extrahepatic malignancies are cholangiocarcinomas (CCAs). They arise owing to a complex interplay between the patient-specific genetic background and multiple risk factors and may occur in the liver (intrahepatic CCA), hilum (perihilar CCA), or extrahepatic bile ducts (distal CCA). Biliary-type adenocarcinoma constitutes the most common histologic type of ampullary and gallbladder malignancies. Its prognosis is poor and surgical resection is considered curative, so early detection is key, with multimodality imaging playing a central role in making the diagnosis. There are several risk factors for biliary malignancy as well as predisposing conditions that increase the risk; this review highlights the pertinent imaging features of these entities with histopathologic correlation. The predisposing factors are broken down into three major categories: (a) congenital malformations such as choledochal cyst and pancreaticobiliary maljunction; (b) infectious or inflammatory conditions such as parasitic infections, hepatolithiasis, primary sclerosing cholangitis, and porcelain gallbladder; and (c) preinvasive epithelial neoplasms such as biliary intraepithelial neoplasm, intraductal papillary neoplasm of the bile duct, intra-ampullary papillary tubular neoplasm, and intracholecystic papillary neoplasm of the gallbladder. Recognizing the baseline features of these premalignant biliary entities and changes in their appearance over time that indicate the advent of malignancy in high-risk patients can lead to early diagnosis and potentially curative management. An invited commentary by Volpacchio is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Application of imaging techniques in pancreaticobiliary maljunction

Imaging techniques are useful tools in the diagnosis and treatment of pancreaticobiliary maljunction (PBM). PBM is a precancerous lesion often relative to the disease of the pancreas and biliary tract, for example, cholecystolithiasis, protein plugs, and pancreatitis. For patients with PBM, early diagnosis and timely treatment are highly important, which is largely dependent on imaging techniques. The continuous development of imaging techniques, including endoscopic retrograde cholangiopancreatography, magnetic resonance cholangiopancreatography, computed tomography, ultrasound, and intraoperative cholangiography, has provided appropriate diagnostic and therapeutic tools for PBM. Imaging techniques, including non-invasive and invasive, have distinct advantages and disadvantages. The purpose of this paper is to review the application of various imaging techniques in the diagnosis and treatment of PBM.

Progress in research of pancreaticobiliary maljunction and biliary dilatation

Pancreaticobiliary maljunction (PBM) is a congenital anomaly that is defined as a junction of the pancreatic and bile ducts located outside the duodenal wall during the embryonic stage, resulting in bile and pancreatic juice reflux and corresponding clinical symptoms. PBM is a high risk factor for cholangiocarcinoma. PBM can occur with or without biliary dilatation (BD). Early diagnosis of PBM can prevent complications. Ultrasonography, magnetic resonance imaging, multi-slice spiral computed tomography, endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography, and cholangiopancreatography are important modalities for diagnosis of this disease. The standard surgical procedure for PBM with BD is dilated cholangiectomy and choledochoenteroreconstruction. Cholecystectomy should be performed as early as possible for PBM without BD.

Precursor Lesions of Gallbladder Carcinoma: Disease Concept, Pathology, and Genetics

Understanding the pathogenesis and carcinogenesis of gallbladder adenocarcinoma is important. The fifth edition of the World Health Organization’s tumor classification of the digestive system indicates three types of preinvasive neoplasm of the gallbladder: pyloric gland adenoma (PGA), biliary intraepithelial neoplasia (BilIN), and intracholecystic papillary neoplasm (ICPN). New terminologies have also been introduced, such as intracholecystic papillary-tubular neoplasm, gastric pyloric, simple mucinous type, and intracholecystic tubular non-mucinous neoplasm (ICTN). Pancreatobiliary maljunction (PBM) poses a markedly high risk for bile duct carcinoma, which was analyzed and investigated mainly by Asian researchers in the past; however, recent studies have clarified a similar significance of biliary carcinogenesis in Western countries as well. In this study, we reviewed and summarized information on three gallbladder neoplastic precursors, PGA, BilIN, and ICPN, and gallbladder lesions in patients with PBM.

Retrospective Analysis of the Accuracy of High-Frequency Ultrasound for Pancreaticobiliary Maljunction in Pediatrics at a Single Center

OBJECTIVE

To determine the clinical value of high-frequency ultrasonography (US) in the evaluation and diagnosis of pancreaticobiliary maljunction (PBM) among children.

METHODS

The clinical subjects consisted of 31 pediatric patients who were diagnosed with PBM from January 2015 to May 2021 in Fujian Provincial Maternity and Children's Hospital. The primary outcomes included diagnosis accuracy, imaging characteristics of each type of PBM based on JSPBM, time length of operation, and cost of service. Secondary outcomes were the serum amylase and bilirubin levels.

RESULTS

The diagnostic accuracy of US was 90.3% and comparable to the other imaging methods-MRCP (82.6%), IOC (79.2%), and ERCP (100%), respectively. The time length of operation and direct cost were significantly lower than other imaging pathways. Stenotic type (A) is associated with a high internal diameter of CBD, and dilated channel type (C) presents increased internal diameter and length of CC as well as internal diameter of PD. There were higher levels of the serum bilirubin seen in type A and of serum amylase in type C compared with others.

CONCLUSION

High-frequency US is a safe, cost-effective, and non-invasive imaging tool for the diagnosis and evaluation of PBM in pediatrics.

Application of Embedding Hepaticojejunostomy in Children with Pancreaticobiliary Maljunction Without Biliary Dilatation

Background: To investigate the effect of embedded hepaticojejunostomy in children with pancreaticobiliary maljunction (PBM) without biliary dilatation. Materials and Methods: The clinical data of 10 patients with nondilated PBM from February 2017 to July 2020 were retrospectively analyzed. Perioperative liver function indexes were compared. Results: All patients were diagnosed by magnetic resonance cholangiopancreatography (MRCP) combined with intraoperative cholangiography. There were 5 cases of Komi type I and 5 cases of type II; the diameter of the common bile duct was 4-9 mm (median: 6 mm); and the length of the common channel was 5-15 mm (median: 9.25 mm). The procedure for one patient with common duct stones was converted to open surgery. Laparoscopic cholecystectomy, common bile duct resection, and embedded hepaticojejunostomy were successfully performed in all 10 cases. The average operation time was 225 ± 96.64 min, and the intraoperative blood loss was 2-5 mL. The mean time to oral intake was 3.5 ± 1.65 days (range: 2-5 days), and the mean hospitalization duration was 6.2 ± 2.44 days (range: 5-8 days). The differences in liver function indexes in the perioperative period were statistically significant (P < .05). The patients were followed-up for 13 to 54 months (median: 40 months). All patients grew well and there was no bile duct dilatation, calculus, or cirrhosis on B-ultrasound examinations. Conclusions: The clinical manifestations of nondilated PBM are often concealed, and preoperative MRCP was important for obtaining a diagnosis. Laparoscopic cholecystectomy, common bile duct resection, and embedded hepaticojejunostomy are feasible for treating nondilated PBM.

Imaging of Ampullary and Periampullary Conditions

The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct and is also known as hepatopancreatic ampulla or hepatopancreatic duct. The ampulla is surrounded by a muscular valve known as the sphincter of Oddi, which controls the flow of bile and pancreatic juices into the duodenum in response to food. The ampulla is also an important embryological landmark as it marks the anatomical transition from foregut to the midgut. Because of this, it is a watershed zone where the blood supply changes from the celiac axis to the superior mesenteric artery. Radiologic evaluation of the ampulla and the periampullary region is challenging because it requires an understanding of the embryology, the normal appearance, and different anatomic variants. Also, a wide variety of pathologies can occur in this region. The purpose of this review is to present the normal anatomy of the ampulla and the periampullary region on different imaging modalities and to summarize the imaging features of the common variants, and benign and malignant ampullary and periampullary conditions. Understanding of the normal anatomical appearance and variants along with the knowledge of common pathologic conditions affecting the ampulla and periampullary conditions can help radiologists in making accurate diagnosis resulting in optimum patient care.

Complex Pancreaticobiliary Maljunction with Pancreas Divisum and Obstructive Pseudocyst

Pancreaticobiliary maljunction (PBM) is the congenital junction of the bile and pancreatic ducts into a common channel located anatomically outside of the duodenal wall. The complex type (Type D) is the rarest type and occurs in conjunction with other pancreaticobiliary anomalies. We present a case of complex PBM with pancreas divisum presenting as acute pancreatitis and obstructive symptoms secondary to a pancreatic pseudocyst. Surgical management is discussed, as complex type PBM is most predisposed to post-operative complications.

Gallbladder Cancer: Imaging Appearance and Pitfalls in Diagnosis [Formula: see text]

Gallbladder cancer is an uncommon malignancy with an overall poor prognosis. The clinical and imaging presentation of gallbladder cancer often overlaps with benign disease, making diagnosis difficult. Gallbladder cancer is most easily diagnosed on imaging when it presents as a mass replacing the gallbladder. At this stage, the prognosis is usually poor. Recognizing the features of gallbladder cancer early in the disease can enable complete resection and improve prognosis. Recognition of the patterns of wall enhancement on computed tomography can help differentiate gallbladder cancer from benign disease. Gallbladder wall thickening without pericholecystic fluid presenting in an older patient with raised alkaline phosphatase should raise concern regarding gallbladder cancer. Gallbladder polyps in high-risk individuals need close surveillance or surgery as per guidelines. Small gallbladder cancers in the neck can present as biliary dilatation or cholecystitis, and careful examination of this area is needed to assess for lesion. The imaging appearance of gallbladder cancer is reviewed and supported by local institutional data. Features that differentiate it from its common mimics enabling earlier diagnosis are described.