Radiologic manifestations of sclerosing cholangitis with emphasis on MR cholangiopancreatography

Atlas for Cholangioscopy and Cholecystoscopy: A Primer for Diagnostic and Therapeutic Endoscopy in the Biliary Tree and Gallbladder

Percutaneous endoscopy of the biliary system (cholangioscopy) and gallbladder (cholecystoscopy) has significantly impacted diagnostic and therapeutic approaches to many diseases in interventional radiology, overcoming previous challenges related to scope size and rigidity. The current endoscopes offer enhanced maneuverability within narrow tubular structures such as bile ducts. Before endoscopy, reliance on 2D imaging modalities limited real-time visualization during percutaneous procedures. Percutaneous endoscopy provides 3D perspectives, enabling a better appreciation of normal structures, targeted biopsy of lesions, and accurate deployment of therapeutic interventions. This review aims to explore percutaneous endoscopic findings across various biliary and gallbladder pathologies.

Primary Sclerosing Cholangitis: Epidemiology, Diagnosis, and Presentation

Primary sclerosing cholangitis (PSC) is considered an immunologically mediated disease. However, some of its features are not consistent with the typical profile of autoimmune conditions. PSC is characterized by progressive biliary fibrosis that may ultimately result in the eventual development of cirrhosis. In recent years, multiple studies have reported that the incidence and prevalence of this disease are on the rise. Consequently, patients are often diagnosed without symptoms or signs of advanced liver disease, although many still present with signs of decompensated liver disease. This article discusses the epidemiology, clinical presentation, and diagnostic workup in patients with PSC.

Primary Sclerosing Cholangitis: Diagnostic Criteria

Primary sclerosing cholangitis is a chronic cholestatic liver disease characterized by inflammation and fibrosis of intra- and/or extrahepatic bile ducts leading to the formation of multifocal strictures alternated to bile duct dilatations. The diagnosis of the most common subtype of the disease, the large duct PSC, is based on the presence of elevation of cholestatic indices, the association of typical cholangiographic findings assessed by magnetic resonance cholangiography and the exclusion of causes of secondary sclerosing cholangitis. Liver biopsy is not routinely applied for the diagnosis of large duct PSC but is mandatory in the case of suspicion of small duct PSC or overlap with autoimmune hepatitis.

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 stratification in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic liver disorder commonly affecting young patients and associated with uncertain prognosis and elevated risk of end-stage liver disease and hepatobiliary cancer. Rate of progression in PSC is heterogeneous and accurately predicting the disease course is of paramount importance to clinical practice and interventional trial design. So far, efforts have brought to the development of models looking at short-to-middle-term outcome using composite models including clinical, laboratory, radiological and histological parameters with limited performance. In the era of whole genome sequencing and digital innovation, the time is ripe for the development of stratified medicine in PSC. Efforts should be directed toward developing well-phenotyped cohorts of patients with longitudinal follow-up across sustained periods of time, application of novel image-processing technology, and biomarker discovery using multiomics platforms.

Primary sclerosing cholangitis: review for radiologists

Primary sclerosing cholangitis is a rare chronic inflammatory disease affecting the bile ducts, which can eventually result in bile duct strictures, cholestasis and cirrhosis. Patients are often asymptomatic but may present with clinical features of cholestasis. Imaging plays an important role in the diagnosis and management. This review covers the pathophysiology, clinical features, imaging findings as well as methods of surveillance and post-transplant appearance.

Secondary sclerosing cholangitis: mimics of primary sclerosing cholangitis

Sclerosing cholangitis is a chronic cholestatic disease characterized by stricturing, beading, and obliterative fibrosis of the bile ducts. Sclerosing cholangitis is considered primary (PSC) if no underlying etiology is identified or secondary (SSC) if related to another identifiable cause. In this article, we will review the clinical features, pathogenesis, diagnosis, and imaging findings of PSC and SSC, with an emphasis on features that may aid in the distinction of these entities. We will also discuss various etiologies of SSC including recurrent pyogenic cholangitis, other infectious etiologies, ischemic damage, toxic insults, and immunologic, congenital, and miscellaneous causes, highlighting the unique imaging findings and clinical context of each diagnosis.

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.

Imaging features of COVID-19-associated secondary sclerosing cholangitis on magnetic resonance cholangiopancreatography: a retrospective analysis

Background

Despite emerging reports of secondary sclerosing cholangitis (SSC) in critically ill COVID-19 patients little is known about its imaging findings. It presents as delayed progressive cholestatic liver injury with risk of progression to cirrhosis. Diagnosis cannot be made based on clinical presentation and laboratory markers alone. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) can aid in the diagnosis. The aim of this study was to describe MRI/MRCP imaging features of COVID-19-associated SSC.

Results

Seventeen patients (mean age 60.5 years, 15 male) who underwent MRI/MRCP were included. All had been admitted to intensive care unit (ICU) (median duration of ICU stay 10 weeks, range, 2–28 weeks) and developed acute respiratory distress syndrome requiring mechanical ventilation. On imaging, all patients had intrahepatic bile duct strictures and 10 (58.8%) had associated upstream dilatation. Intrahepatic bile duct beading was seen in 14 cases (82.3%). Only one patient (5.9%) had extrahepatic bile duct stricturing. Patchy arterial phase hyperenhancement and high signal on T2- and diffusion-weighted images were seen in 7 cases (53.8%) and 9 cases (52.9%), respectively. Biliary casts were seen in 2 cases (11.8%). Periportal lymphadenopathy and vascular complications were not seen.

Conclusion

On MRI/MRCP, COVID-19-associated SSC presents with multiple intrahepatic bile duct strictures with or without upstream dilatation and intrahepatic bile duct beading. Surrounding hepatic parenchymal changes including alterations in enhancement and T2 signal are common. The extrahepatic biliary tree was typically spared and periportal lymphadenopathy was missing in all patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01266-9.

Metastatic Biliary Stricture with "Beaded" Appearance from Cervical Adenocarcinoma

Cervical adenocarcinoma accounts for 25% of invasive cervical cancer which frequently metastasize distantly to the lungs, liver, bone, and brain. Metastases to the common bile duct from cervical cancer are exceedingly rare with few reported cases in the literature. Diagnosis of bile duct metastases from cervical cancer can be established with endoscopic ultrasound-guided fine-needle aspiration cytology, biliary cytobrushing, or direct cholangioscopy with biopsy, and this would guide further therapies such as endoscopic biliary drainage and systemic chemotherapy. We hereby present a rare case of obstructive jaundice from metastatic biliary stricture with “beaded” appearance in a patient with cervical adenocarcinoma.

How to cite this article: Lee SL, Sidhu J, Ng CY. Metastatic Biliary Stricture with “Beaded” Appearance from Cervical Adenocarcinoma. Euroasian J Hepato-Gastroenterol 2021;11(2):97–99.

Modern imaging of cholangitis

Cholangitis refers to inflammation of the bile ducts with or without accompanying infection. When intermittent or persistent inflammation lasts 6 months or more, the condition is classified as chronic cholangitis. Otherwise, it is considered an acute cholangitis. Cholangitis can also be classified according to the inciting agent, e.g. complete mechanical obstruction, which is the leading cause of acute cholangitis, longstanding partial mechanical blockage, or immune-mediated bile duct damage that results in chronic cholangitis.The work-up for cholangitis is based upon medical history, clinical presentation, and initial laboratory tests. Whereas ultrasound is the first-line imaging modality used to identify bile duct dilatation in patients with colicky abdominal pain, cross-sectional imaging is preferable when symptoms cannot be primarily localised to the hepatobiliary system. CT is very useful in oncologic, trauma, or postoperative patients. Otherwise, magnetic resonance cholangiopancreatography is the method of choice to diagnose acute and chronic biliary disorders, providing an excellent anatomic overview and, if gadoxetic acid is injected, simultaneously delivering morphological and functional information about the hepatobiliary system. If brush cytology, biopsy, assessment of the prepapillary common bile duct, stricture dilatation, or stenting is necessary, then endoscopic ultrasound and/or retrograde cholangiography are performed. Finally, when the pathologic duct is inaccessible from the duodenum or stomach, percutaneous transhepatic cholangiography is an option. The pace of the work-up depends upon the severity of cholestasis on presentation. Whereas sepsis, hypotension, and/or Charcot's triad warrant immediate investigation and management, chronic cholestasis can be electively evaluated.This overview article will cover the common cholangitides, emphasising our clinical experience with the chronic cholestatic liver diseases.

Noninvasive Imaging Prior to Biliary Interventions

Noninvasive imaging is a crucial and initial step in the diagnostic algorithm of patients with suspected biliary pathology and directs the subsequent diagnostic and therapeutic workup, including the endoluminal and percutaneous biliary interventions. This article reviews the current noninvasive imaging methods for the evaluation of biliary system and further discusses their roles in the diagnostic workup of different biliary disease.

Diagnostic value of peroral cholangioscopy in addition to computed tomography for indeterminate biliary strictures

BACKGROUND

Peroral cholangioscopy (POCS) has been used to overcome the difficulty in diagnosing indeterminate biliary stricture or tumor spread. However, the value of adding POCS to computed tomography (CT) remains unclear. Our aim was to evaluate the diagnostic value of adding POCS to CT for indeterminate biliary stricture and tumor spread by interpretation of images focusing on the high diagnostic accuracy of visual findings in POCS.

METHODS

We retrospectively identified 52 patients with biliary stricture who underwent endoscopic retrograde cholangiography (ERC) at our institution between January 2013 and December 2018. Two teams, each composed of an expert endoscopist and surgeon, performed the interpretation independently, referring to the CT findings of the radiologist. The CT + ERC + POCS images (POCS group) were evaluated 4 weeks after the evaluation of CT + ERC images (CT group). A 5-point scale (1: definitely benign to 5: definitely malignant) was used to determine the confident diagnosis rate, which was defined as an evaluation value of 1 or 5. Tumor spread was also evaluated.

RESULTS

In the evaluation of 45 malignant diagnoses, the score was significantly closer to 5 in the POCS group than in the CT group in both teams (P < 0.001). The confident diagnosis rate was significantly higher for the POCS group (92% and 73%) than for the CT group (25% and 12%) in teams 1 and 2, respectively (P < 0.001). We found no significant difference in diagnostic accuracy for tumor spread between the groups.

CONCLUSION

Visual POCS findings confirmed the diagnosis of biliary strictures. POCS was useful in cases of indefinite diagnosis of biliary strictures by CT.

Analysis of the Clinical Course of Primary Sclerosing Cholangitis in Paediatric Population-Single Center Study

Background and Objectives: Primary sclerosing cholangitis (PSC) is a rare cholestatic disease of the liver of unknown etiology, severe course and poor prognosis. PSC most often co-occurs with inflammatory bowel diseases (IBD), especially with ulcerative colitis (UC). The aim of the study was the analysis of the clinical course of primary sclerosing cholangitis in children, hospitalized in the Gastroenterology Unit in Katowice. Materials and Methods: The analysis included 30 patients, aged from 7 to 18 years, 21/30 boys (70%) and 9/30 girls (30%), diagnosed with PSC in the years 2009–2019. The analysis included the age at diagnosis, clinical symptoms, course of the disease, coexisting diseases, laboratory and imaging results, and complications. Results: The average age at diagnosis was 13 years. 22/30 (73.3%) patients suffered from UC, 4/30 (13.3%) were diagnosed with Crohn’s disease (CD), 2/30 (6.66%) with Eosinophilic Colitis (EC). 2/30 patients (6.66%) had no clinical evidence of coexistent IBD to date. In addition, 7/30 (23.3%) had an overlap syndrome of primary sclerosing cholangitis/autoimmune hepatitis. When PSC was detected before IBD (6/30–20%), patients had complications more often compared to those diagnosed with IBD first or PSC and IBD at the same time. At the moment of diagnosis 6/30 (20%) patients presented with abdominal pain, which was the most common symptom, 3/30 (10%) jaundice, while 17/30 (56.6%) were asymptomatic but had abnormal results of the laboratory tests. Conclusions: Monitoring liver markers in IBD patients is important since most PSC cases are asymptomatic and their elevation might be the first sign of the disease. Patients diagnosed with PSC before IBD diagnosis are more likely to have a more aggressive course of the disease.

Sclerosing cholangitis in a patient treated with nivolumab

A 69-year-old retired miner with stage 4 non-small-cell lung cancer presented with a 2-month history of obstructive liver function tests following nivolumab immunotherapy. His case had not responded to high dose prednisolone or mycophenolate and he was admitted for investigation. MR cholangiopancreatography demonstrated areas of intrahepatic biliary tree beading and stricturing, in keeping with sclerosing cholangitis. Prednisolone and mycophenolate were stopped and ursodeoxycholic acid commenced with subsequent partial improvement of the patient's liver function tests.

Findings encountered in percutaneous cholangiography in a case of post-transplant recurrence of hepatic Langerhans cell histiocytosis with biliary involvement

This case report describes a four-year-old boy who presented with the diagnosis of LCH with liver involvement. This required a living-related liver transplant one year later. The primary disease recurred in the transplanted liver 6 months post-transplant and led to progressive biliary dilatation. A percutaneous trans-hepatic cholangiogram was performed five years after transplant, showing a pattern of multifocal biliary duct strictures mimicking the pattern of primary sclerosing cholangitis and a stenosis of the biliary-enteric anastomosis. Despite management with an internal-external biliary drain, the stenosis of the biliary-enteric anastomosis evolved to an occlusion one year after drain removal. This was associated with progression of the changes in the biliary tree, this time associated with significant saccular dilatations secondary to the multiple areas of stenosis. Due to these findings and progressive deterioration of the function of the graft, the patient required re-transplantation. This report illustrates the findings in imaging of the biliary tree secondary to the recurrence of LCH after liver transplantation, which may help to recognize this complication to physicians facing a similar clinical scenario.

Eosinophilic Cholangitis with Poor Prognosis after Corticosteroid- and Ursodeoxycholic Acid-Related Remission of Peripheral and Peribiliary Eosinophilia

A 79-year-old man presented with high fever, marked eosinophilia, altered biochemical liver function tests (LFT) with predominance of biliary enzymes, and severe wall thickening of the gallbladder. Magnetic resonance cholangiopancreatography (MRCP) suggested cholecystitis, without signs of biliary strictures. Laparoscopic cholecystectomy and exploratory liver excision revealed eosinophilic cholangitis and cholecystitis, complicated with hepatitis and portal phlebitis. Prednisolone monotherapy rapidly improved peripheral eosinophilia, but not LFT. Liver biopsy showed that infiltrating eosinophils were replaced by lymphocytes and plasma cells. Treatment with ursodeoxycholic acid improved LFT abnormalities. Nevertheless, after 2 months, transaminase-dominant LFT abnormalities appeared. Transient prednisolone dose increase improved LFT, but biliary enzymes' levels re-elevated and jaundice progressed. The second and third MRCP within a 7-month interval showed rapid progression of biliary stricture. The repeated liver biopsy showed lymphocytic, not eosinophilic, peribiliary infiltration and hepatocellular reaction to cholestasis. Eighteen months after the first visit, the patient died of hepatic failure. Autopsy specimen of the liver showed lymphocyte-dominant peribiliary infiltration and bridging fibrosis due to cholestasis. Though eosinophil-induced biliary damage was an initial trigger, repeated biopsy suggested that lymphocytes played a key role in progression of the disease. Further studies are needed to elucidate the relationship between eosinophils and lymphocytes in eosinophilic cholangitis.

Abdominal immune-related adverse events: detection on ultrasonography, CT, MRI and 18F-Fluorodeoxyglucose positron emission tomography

Immune checkpoint inhibitor and chimeric antigen receptor T-cell therapies are associated with a unique spectrum of complications termed immune-related adverse events (irAEs). The abdomen is the most frequent site of severe irAEs that require hospitalization with life-threatening consequences. Most abdominal irAEs such as enterocolitis, hepatitis, cholangiopathy, cholecystitis, pancreatitis, adrenalitis, and sarcoid-like reaction are initially detected on imaging such as ultrasonography (US), CT, MRI and fusion 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT during routine surveillance of cancer therapy. Early recognition and diagnosis of irAEs and immediate management with cessation of immune modulator cancer therapy and institution of immunosuppressive therapy are necessary to avert morbidity and mortality. Diagnosis of irAEs is confirmed by tissue sampling or by follow-up imaging demonstrating resolution. Abdominal radiologists reviewing imaging on patients being treated with anti-cancer immunomodulators should be familiar with the imaging manifestations of irAEs.

Use of diffusion-weighted imaging in the noninvasive diagnostic of obstructed biliary ducts

OBJECTIVE

This study sought to evaluate the role of diffusion-weighted imaging (DWI) in differentiation between obstructed and unobstructed bile ducts in patients undergoing magnetic resonance imaging (MRI).

METHODS

Eighty-four patients, 40 males and 44 females (mean age: 56.4 ± 15.1 years), undergoing MRI with DWI (0-50-500-700) were evaluated and divided into two groups: 58 with abnormal laboratory tests (obstructed group) and 26 with normal laboratory values (unobstructed group). Laboratory tests were total bilirubin, alkaline phosphatase, and gamma-glutamyltransferase. Median ADC values were calculated and correlated with laboratory tests and degree of bile-duct dilatation (absent, moderate, or severe). The persistence of signal on DWI (b500 and b700) in the biliary tract was evaluated. Bilirubin values were tested for correlation with bile-duct ADC values and persistence of b700 signal. For statistical analysis, Student t test, chi-square test and Wilcoxon-Mann-Whitney test were used. ADC maps were plotted for three levels of the biliary tree, and a receiver operating characteristic (ROC) curve was calculated.

RESULTS

In the obstructed group, 15 patients had severe dilatation, 24 had moderate dilatation, and 19 had no appreciable dilatation; 38 patients had persistent signal on b700 images. In the unobstructed group, 23 patients had no dilatation and 3 had moderate dilatation; 4 patients had persistent signal on b700 images. Correlation was found between degree of bile-duct dilatation, bilirubin levels, persistence of b700 signal, and ADC map values. The calculated ADC map cutoff value (353 10^-6 mm²/s) was able to differentiate the obstructed and unobstructed groups with 92.3% sensitivity, 81% specificity, and 91.9% accuracy.

CONCLUSIONS

DWI is able to distinguish patients with obstructed versus unobstructed bile ducts, regardless of the degree of dilatation, correlating with clinical and laboratory findings.

Factors associated with major radiological progression of primary sclerosing cholangitis in patients with inflammatory bowel disease

BACKGROUND/PURPOSE OF THE STUDY

Primary sclerosing cholangitis (PSC) is the most common hepatobiliary manifestation of inflammatory bowel disease (IBD). Magnetic resonance cholangiography (MRC) has become the primary diagnostic modality for PSC. However, data on radiological progression over time of large-duct PSC-IBD are limited.

METHODS

We performed a nested case-control study to estimate the frequency of PSC in adult patients with IBD from a Middle Eastern population to assess the risk factors associated with major disease progression (formation of dominant strictures or cholangiocarcinoma) over time.

RESULTS

Data of IBD patients who were registered in the Saudi IBD Information System at tertiary care center were analyzed. Among 960 patients [477 ulcerative colitis (UC); 483 Crohn's disease (CD)], 40 PSC-IBD patients with at least two MRC performed in a one-year interval were matched with 141 IBD patients without PSC. The frequency of PSC was 4.1%. UC patients (6.2%) compared to CD (2%), 65% had extensive colitis. The incidence rate of PSC among our cohort was increased from 2.62 to 10 per 1000 patient-years between 2005 and 2019. MRC features stabilized in (46.7%); worsened in (36.9%) and 15.4% of patients developed CCA. Alkaline phosphatase (ALP) levels of PSC patients who had major changes or CCA increased significantly after 44 months of follow-up (p = 0.01). The propensity score adjusted showed that hospitalization rate among PSC patients was higher than their non-PSC counterparts (OR 8.24; 95% CI 3.16-21.47; p < 0.01).

CONCLUSION

ALP rise and hospitalization history as clinical outcome were the only factors associated with PSC-IBD major progression on MRCP.

Differentiating pediatric autoimmune liver diseases by quantitative magnetic resonance cholangiopancreatography

PURPOSE

Autoimmune liver diseases (AILD), including primary sclerosing cholangitis (PSC), autoimmune sclerosing cholangitis (ASC), and autoimmune hepatitis (AIH), have overlapping clinical features but distinct management strategies and outcomes. The purpose of this study was to assess the diagnostic performance of quantitative magnetic resonance cholangiopancreatography (MRCP) parameters for distinguishing PSC/ASC from AIH in children and young adults.

MATERIALS AND METHODS

This IRB-approved, cross-sectional study included participants from an institutional AILD registry that underwent baseline serum liver biochemistry testing and 3D fast spin-echo MRCP. The biliary tree was extracted and modeled from MRCP images using novel proprietary software (MRCP+ ™; Perspectum Diagnostics; Oxford, United Kingdom), and quantitative parameters were generated (e.g., biliary tree volume; number and length of bile ducts, strictures, and dilations; bile duct median/maximum diameters). Mann-Whitney U tests were performed to compare laboratory values and MRCP metrics between patient cohorts (clinical diagnosis of PSC/ASC versus AIH). Receiver operating characteristic (ROC) curves and multivariable logistic regression were used to assess diagnostic performance of serum biochemistry values and MRCP parameters for discriminating PSC/ASC from AIH.

RESULTS

Thirty percent (14/47) of MRCP exams failed post-processing due to motion artifact. The remaining 33 patients included 20 males and 13 females, with a mean age of 15.1 ± 3.9 years. Eighteen patients were assigned the clinical diagnosis of PSC or ASC and 15 of AIH. All but one quantitative MRCP parameter were significantly different between cohorts (p < 0.05) and predictive of diagnosis (ROC p < 0.05), including numbers of bile duct strictures (area under curve [AUC] = 0.86, p < 0.0001) and dilations (AUC = 0.87, p < 0.0001) and total length of dilated ducts (AUC = 0.89, p < 0.0001). Laboratory values were not significantly different between cohorts (p > 0.05). The best multivariable model for distinguishing PSC/ASC from AIH included total length of dilated ducts (odds ratio [OR], 1.08; 95% CI 1.02-1.14) and maximum left hepatic duct diameter (OR, 1.21; 95% CI 0.57-2.56) [AUC = 0.92].

CONCLUSION

Quantitative MRCP parameters provide good discrimination of PSC/ASC from AIH.

Early detection of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is a malignant tumor which arises from the biliary epithelium and most cases represent adenocarcinoma. CC can be classified into intrahepatic CC (ICC), perihilar CC, and distal CC, based on the site of anatomic origin. The incidence of ICC is increasing in both Western and Eastern countries, while that of extrahepatic cholangiocarcinoma remains fairly stable. ICC infiltrates into adjacent nerves and lymphatic vessels, resulting in progressive disease with a poor prognosis; thus, early detection of ICC is critical for achieving better outcomes and providing better patient care. However, it is difficult for clinicians to detect an ICC, especially in its early stage. Different from hepatocellular carcinoma, the lack of surveillance system for the high-risk group of CC does not allow for a reliable screening examination. In this context, for early detection and diagnosis of ICC, radiologists need to know predisposing conditions that can lead to the development of ICC, such as chronic biliary or hepatic inflammation, primary sclerosing cholangitis, congenital biliary diseases, and other conditions. In this article, we discuss and illustrate the radiologic features of ICC with special attention to early disease stages and of predisposing conditions of ICC.

Uncommon Intraluminal Tumors of the Gallbladder and Biliary Tract: Spectrum of Imaging Appearances

Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ^©RSNA, 2019.

The Clinical Significance of Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography in Patients with Occupational Cholangiocarcinoma

Objective

The present study aimed to identify the clinical significance of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging in patients with occupational cholangiocarcinoma.

Methods

This study included 10 men with occupational cholangiocarcinoma who were former or current workers at a printing company in Osaka, Japan. Of the 10 patients, 2 had 2 main tumors and 1 had 3 main tumors. Twelve FDG-PET imaging findings in the 10 patients could be analyzed. We evaluated the relationships between FDG-PET imaging parameters and clinicopathological findings of occupational cholangiocarcinoma.

Results

Abnormal FDG uptake was observed in 8 of the 14 main tumors, with maximum standardized uptake values ranging from 2.9 to 11.0, and the sensitivity was 57.1%. Four patients had lymph node metastases, and abnormal marrow uptake was detected in all these patients. Although precancerous lesions, such as biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB) without any invasion, were not detected, abnormal FDG uptake was demonstrated in 2 of 4 patients with IPNB having an associated invasive carcinoma.

Conclusions

Although FDG-PET may be useful for assessing tumor progression factors, such as lymph node metastasis, it cannot accurately detect precancerous lesions, such as BilIN and IPNB without invasive carcinoma.

Benign Sclerosing and Fibrosing Conditions of the Abdomen and Their Potential Mimics

The process of abnormal reparative or reactive processes in the abdominal cavity, can lead to sclerosis and fibrous deposition. The relatively recent discovery of an IgG4 subgroup of immune mediated sclerosing disease 1,2 has thrown some light on the pathophysiology of these conditions. Firstly, our pictorial review aims to describe imaging findings to enhance the general radiologist's recognition and interpretation of this varied group of benign sclerotic and fibrotic abdominal processes. Secondly, along with the imaging findings, we bring into discussion the potential mimics of these pathologic processes to minimise interpretational errors. Moreover, some of the mimics of these processes are in the spectrum of malignant disease. Most importantly, to ensure a correct diagnosis thorough clinical and histopathological assessment are required to support the imaging findings presented in this review.

Biliary and pancreatic complications of molecular targeted therapies in cancer imaging

The purpose of this review is to familiarize radiologists with the different imaging manifestations of biliary and pancreatic toxicity of molecular targeted therapies. The advent of molecular targeted therapies for cancer treatment has prompted radiologists to be familiar with these new molecules, their patterns of response, and their class-specific toxicities. While liver and bowel toxicities have been extensively reported in literature, less is known about the pathogenesis and imaging of toxicity involving the pancreatobiliary system. Biliary and pancreatic toxicity of molecular targeted therapies present with variable manifestations and varying degrees of severity, from asymptomatic liver function tests elevation to acute pancreatitis or cholecystitis. Management of these conditions depends on the clinical scenario and the severity of the findings. In this article, we will (1) present the various classes of molecular targeted therapies most commonly associated with biliary and pancreatic toxicity; (2) illustrate imaging findings of drug-associated biliary and pancreatic injuries and their possible differential diagnosis; and (3) provide a guide for management of these conditions.

MR imaging and MR cholangiopancreatography of cholangiocarcinoma developing in printing company workers

PURPOSE

To retrospectively investigate magnetic resonance (MR) imaging findings of occupational cholangiocarcinoma (oCC) occurring among workers in printing companies in Japan, compared to those of non-occupational cholangiocarcinoma (nCC), primary sclerosing cholangitis (PSC), and age-matched normal controls (NORs).

MATERIALS AND METHODS

Participants comprised 27 consecutive patients (oCC, n = 5; nCC, n = 8; PSC, n = 6; NOR, n = 8) who underwent MR imaging between May 2009 and October 2012. MR imaging was evaluated with respect to tumor characteristics, abnormal MR cholangiographic findings (PSC-like findings), bile duct stricture, and signal changes of the hepatic parenchyma.

RESULTS

Tumors were detected in all nCCs and four oCCs. Tumors displayed a mass-forming type in all nCCs and two oCCs, and an intraductal growth type in two oCCs. Abnormal cholangiographic findings were detected in all oCCs and PSCs, but not in any nCCs or NORs. All oCCs and seven nCCs showed biliary strictures longer than 1 cm; five PSCs showed biliary strictures shorter than 1 cm. Both intra- and extrahepatic biliary strictures were detected in three PSCs and two oCCs. Peripheral hepatic hyperintensity on T2-weighted imaging was detected in two nCCs, two PSCs, and two oCCs.

CONCLUSION

These results indicated that MR imaging of oCC showed findings of both PSC and nCC.

Diagnostic Imaging of the Hepatobiliary System: An Update

Recent advances in diagnostic imaging of the hepatobiliary system include MRI, computed tomography (CT), contrast-enhanced ultrasound, and ultrasound elastography. With the advent of multislice CT scanners, sedated examinations in veterinary patients are feasible, increasing the utility of this imaging modality. CT and MRI provide additional information for dogs and cats with hepatobiliary diseases due to lack of superimposition of structures, operator dependence, and through intravenous contrast administration. Advanced ultrasound methods can offer complementary information to standard ultrasound imaging. These newer imaging modalities assist clinicians by aiding diagnosis, prognostication, and surgical planning.

Imaging of autoimmune biliary disease

Autoimmune biliary diseases are poorly understood but important to recognize. Initially, autoimmune biliary diseases are asymptomatic but may lead to progressive cholestasis with associated ductopenia, portal hypertension, cirrhosis, and eventually liver failure. The three main forms of autoimmune biliary disease are primary biliary cirrhosis, primary sclerosing cholangitis, and IgG4-associated cholangitis. Although some overlap may occur between the three main autoimmune diseases of the bile ducts, each disease typically affects a distinct demographic group and requires a disease-specific diagnostic workup. For all the autoimmune biliary diseases, imaging provides a means to monitor disease progression, assess for complications, and screen for the development of hepatobiliary malignancies that are known to affect patients with these diseases. Imaging is also useful to suggest or corroborate the diagnosis of primary sclerosing cholangitis and IgG4-associated cholangitis. We review the current literature and emphasize radiological findings and considerations for these autoimmune diseases of the bile ducts.

Early Peribiliary Hyperenhancement on MRI in Patients with Primary Sclerosing Cholangitis: Significance and Association with the Mayo Risk Score

The aims of this study are to assess any relationship between peribiliary hyperenhancement on MRI in patients with primary sclerosing cholangitis (PSC) and their Mayo risk score and to assess which timing of peribiliary hyperenhancement correlates best with the Mayo risk score. In this HIPAA-compliant, IRB-approved retrospective study, 101 patients who underwent MRI for known or suspected PSC were identified. Of those, 62 patients (mean age 48 years; 40 males) were diagnosed with PSC by a hepatologist based on findings on MRI, ERCP, and/or liver biopsy, and comprise the final cohort. Data were recorded on whether peribiliary hyperenhancement was present, the post-contrast phase and the extent of involvement. The components to calculate the Mayo risk score were recorded. Statistical analysis was performed using the student T test, Fisher's exact test, and the Kaplan-Meier estimate. Of 62 patients, 41 (66.1%) patients had a low-Mayo risk score (<0), 14 (22.6%) had an intermediate-risk score (≤2 and >0), and 7 (11.3%) had a high-risk score (>2). On MRI, 29 (46.8%) patients demonstrated arterial peribiliary hyperenhancement. Both the presence and extent of peribiliary hyperenhancement showed significant associations with Mayo risk score (p < 0.01). Using the combined end point of liver transplantation or death, there was a statistically significant difference in survival times between those with and those without arterial peribiliary hyperenhancement (p < 0.05). The presence of arterial peribiliary hyperenhancement in patients with PSC on MRI is associated with higher Mayo risk scores and may suggest a poorer prognosis.

Magnetic resonance imaging of pancreaticobiliary diseases in children: from technique to practice

Magnetic resonance imaging is useful for evaluating pancreaticobiliary diseases in children after initial sonography, obviating the use of ionizing radiation or invasive procedures such as endoscopic retrograde cholangiopancreatography (ERCP) or transhepatic biliary procedures. Advanced MRI applications have improved depiction of pediatric pancreaticobiliary anatomy and have greatly impacted management of biliary and pancreatic diseases in children. In this article, we review current MRI and magnetic resonance cholangiopancreatography (MRCP) techniques and discuss their role in the assessment of common pancreatic and biliary disorders in children.

Biliary strictures and masses: an expanded differential diagnosis

Biliary strictures and masses are commonly a result of cholangiocarcinoma. However, there are several congenital, infectious, inflammatory, autoimmune, iatrogenic, and neoplastic etiologies that should also be considered in the differential diagnosis. Knowledge of the key imaging and clinical findings will aid in facilitating the diagnosis and treatment.

Computed Tomography and MRI of the Hepatobiliary System and Pancreas

MRI and computed tomographic (CT) imaging are becoming more common in the diagnosis of hepatobiliary and pancreatic disorders in small animals. With the advent of multislice CT scanners, sedated examinations in veterinary patients are feasible increasing the use of this imaging modality. CT and MRI provide additional information for dogs and cats with hepatobiliary and pancreatic diseases because of lack of superimposition of structures, operator dependence, and through intravenous contrast administration. This added value provides more information for diagnosis, prognosis, and surgical planning.

Sclerosing Cholangitis: Clinicopathologic Features, Imaging Spectrum, and Systemic Approach to Differential Diagnosis

Sclerosing cholangitis is a spectrum of chronic progressive cholestatic liver disease characterized by inflammation, fibrosis, and stricture of the bile ducts, which can be classified as primary and secondary sclerosing cholangitis. Primary sclerosing cholangitis is a chronic progressive liver disease of unknown cause. On the other hand, secondary sclerosing cholangitis has identifiable causes that include immunoglobulin G4-related sclerosing disease, recurrent pyogenic cholangitis, ischemic cholangitis, acquired immunodeficiency syndrome-related cholangitis, and eosinophilic cholangitis. In this review, we suggest a systemic approach to the differential diagnosis of sclerosing cholangitis based on the clinical and laboratory findings, as well as the typical imaging features on computed tomography and magnetic resonance (MR) imaging with MR cholangiography. Familiarity with various etiologies of sclerosing cholangitis and awareness of their typical clinical and imaging findings are essential for an accurate diagnosis and appropriate management.

Pathological spectrum of bile duct lesions from chronic bile duct injury to invasive cholangiocarcinoma corresponding to bile duct imaging findings of occupational cholangiocarcinoma

BACKGROUND

We aimed to identify the pathological characteristics of occupational cholangiocarcinoma.

METHODS

We examined the location and distribution of the carcinomas: atypical epithelium including biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the bile duct (IPNB); and chronic bile duct injuries in operative or autopsy liver specimens from 16 patients. We examined the detailed pathological findings and diagnostic imaging of three patients. Immunohistochemical analysis using primary antibodies against γH2AX and S100P was performed.

RESULTS

BilIN and chronic bile duct injury were observed in 16 patients, and IPNB or invasive IPNB was observed in 11 patients. BilIN, IPNB, and/or chronic bile duct injury were observed in almost all the large bile ducts. Regional dilatation of the bile ducts without tumor-induced obstruction revealed such pathological changes. Highly positive results for the γH2AX and S100P markers were noted in invasive carcinoma, BilIN, and IPNB, whereas positive results for γH2AX and negative results for S100P were noted in non-neoplastic biliary epithelium.

CONCLUSIONS

The carcinogenic process of occupational cholangiocarcinoma comprised chronic bile duct injury and DNA damage in almost all the large bile ducts, along with induction of precancerous lesions and development of invasive carcinoma. Such pathological findings reflected radiological changes on diagnostic imaging.

Magnetic resonance cholangiography: Current and future perspectives

Magnetic resonance cholangiography (MRC) has become the standard of reference for imaging of the biliary ducts. The use of three-dimensional (3D) sequences has resulted in improved spatial resolution with virtually isotropic voxel and improved signal/noise ratio. In addition to MRC images, 3D fat suppressed T1-weighted MR images should be systematically obtained to search for intrahepatic calculi. MRC plays a major role in the diagnosis of cholangiocarcinoma and assessment of its resectability. With modern MR systems the performance of MR is basically the same that of CT for evaluation of arterial and portal vein extent. MRC is a key imaging modality for the diagnosis of primary sclerosing cholangitis. Different imaging patterns may be observed including multifocal intra- and extrahepatic strictures alternating with slightly dilated ducts. Focal signal abnormality of the liver parenchyma and focal parenchymal atrophy represent the consequences of biliary duct obstruction on liver parenchyma. Diagnosis of biliary lithiasis is performed by combination of MRC and T1-weighted MR imaging. MRC can be performed for the diagnosis of secondary cholangitis including ascending cholangitis, ischemic cholangitis and IgG4-related sclerosing cholangitis. Hepatobiliary contrast agents could be used for demonstrating the site of biliary duct leakage after surgery and for functional imaging. MR imaging can also be used to determine the prognosis of PSC. The inherent limitations of MRC of bile ducts are still the suboptimal spatial resolution for evaluation of distal intrahepatic biliary ducts.

Noninvasive Imaging of the Biliary Tree for the Interventional Radiologist

Patients with suspected biliary tract disease often pose a diagnostic challenge to the clinician and radiologist. Although advances across all imaging modalities, including ultrasound, computed tomography, and magnetic resonance, have improved our diagnostic accuracy for biliary disease, many of the imaging findings remain nonspecific. Recognition of key imaging findings combined with knowledge and understanding of the clinical context is essential to piecing together a diagnosis and guiding management for patients with biliary disease. Although there is a wide range of biliary pathology, interventional radiologists most commonly play a role in the management of biliary obstruction and leak.

Adult bile duct strictures: role of MR imaging and MR cholangiopancreatography in characterization

Bile duct strictures in adults are secondary to a wide spectrum of benign and malignant pathologic conditions. Benign causes of bile duct strictures include iatrogenic causes, acute or chronic pancreatitis, choledocholithiasis, primary sclerosing cholangitis, IgG4-related sclerosing cholangitis, liver transplantation, recurrent pyogenic cholangitis, Mirizzi syndrome, acquired immunodeficiency syndrome cholangiopathy, and sphincter of Oddi dysfunction. Malignant causes include cholangiocarcinoma, pancreatic adenocarcinoma, and periampullary carcinomas. Rare causes include biliary inflammatory pseudotumor, gallbladder carcinoma, hepatocellular carcinoma, metastases to bile ducts, and extrinsic bile duct compression secondary to periportal or peripancreatic lymphadenopathy. Contrast material-enhanced magnetic resonance (MR) imaging with MR cholangiopancreatography is extremely helpful in the noninvasive evaluation of patients with obstructive jaundice, an obstructive pattern of liver function, or incidentally detected biliary duct dilatation. Some of these conditions may show characteristic findings at MR imaging-MR cholangiopancreatography that help in making a definitive diagnosis. Although endoscopic retrograde cholangiopancreatography with tissue biopsy or surgery is needed for the definitive diagnosis of many of these strictures, certain MR imaging characteristics of the narrowed segment (eg, thickened wall, long-segment involvement, asymmetry, indistinct outer margin, luminal irregularity, hyperenhancement relative to the liver parenchyma) may favor a malignant cause. Awareness of the various causes of bile duct strictures in adults and familiarity with their appearances at MR imaging-MR cholangiopancreatography are important for accurate diagnosis and optimal patient management.

Characterization of cultured cholangiocytes isolated from livers of patients with primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, idiopathic cholangiopathy. The role of cholangiocytes (biliary epithelial cells) in PSC pathogenesis is unknown and remains an active area of research. Here, through cellular, molecular and next-generation sequencing (NGS) methods, we characterize and identify phenotypic and signaling features of isolated PSC patient-derived cholangiocytes. We isolated cholangiocytes from stage 4 PSC patient liver explants by dissection, differential filtration and immune-magnetic bead separation. We maintained cholangiocytes in culture and assessed for: (i) cholangiocyte, cell adhesion and inflammatory markers; (ii) proliferation rate; (iii) transepithelial electrical resistance (TEER); (iv) cellular senescence; and (v) transcriptomic profiles by NGS. We used two well-established normal human cholangiocyte cell lines (H69 and NHC) as controls. Isolated PSC cells expressed cholangiocyte (eg, cytokeratin 7 and 19) and epithelial cell adhesion markers (EPCAM, ICAM) and were negative for hepatocyte and myofibroblast markers (albumin, α-actin). Proliferation rate was lower for PSC compared with normal cholangiocytes (4 vs 2 days, respectively, P<0.01). Maximum TEER was also lower in PSC compared with normal cholangiocytes (100 vs 145 Ωcm(2), P<0.05). Interleukin-6 (IL-6) and IL-8 (protein and mRNA) were both increased compared with NHCs and H69s (all P<0.01). The proportion of cholangiocytes staining positive for senescence-associated β-galactosidase was higher in PSC cholangiocytes compared with NHCs (48% vs 5%, P<0.01). Finally, NGS confirmed cholangiocyte marker expression in isolated PSC cholangiocytes and extended our findings regarding pro-inflammatory and senescence-associated signaling. In conclusion, we have demonstrated that high-purity cholangiocytes can be isolated from human PSC liver and grown in primary culture. Isolated PSC cholangiocytes exhibit a phenotype that may reflect their in vivo contribution to disease and serve as a vital tool for in vitro investigation of biliary pathobiology and identification of new therapeutic targets in PSC.