Gd-EOB-DTPA-enhanced magnetic resonance imaging for bile duct intraductal papillary mucinous neoplasms

Biliary Duct Dilatation: AJR Expert Panel Narrative Review

Biliary duct dilatation is a common incidental finding in practice, but it is unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated levels on liver function tests (LFTs). However, the clinical presentation may be nonspecific, and LFTs may either be unavailable or difficult to interpret. The goal of this AJR Expert Panel Narrative Review is to highlight a series of topics fundamental to the management of biliary duct dilatation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting LFT results, the strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define the criteria for biliary duct dilatation, including patients with prior cholecystectomy and advanced age, and discuss when and whether biliary duct dilatation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilatation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance regarding when to recommend obtaining additional imaging or testing, such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.

MRI features of intraductal papillary mucinous neoplasm of the bile ducts, "The myth about the cyst": A systematic review

Rationale and objectives

Intraductal papillary mucinous neoplasm of the bile ducts (IPMN-B) is a true pre-cancerous lesion, which shares common features with pancreatic IPMN (IPMN-P). While IPMN-P is a well described entity for which guidelines were formulated and revised, IPMN-B is a poorly described entity.We carried out a systematic review to evaluate the existing literature, emphasizing the role of MRI in IPMN-B depiction.

Materials and methods

PubMed database was used to identify original studies and case series that reported MR Imaging features of IPMN-B. The search keywords were "IPMN OR intraductal papillary mucinous neoplasm OR IPNB OR intraductal papillary neoplasm of the bile duct AND Biliary OR biliary cancer OR hepatic cystic lesions". Risk of bias and applicability were evaluated using the QUADAS-2 tool.

Results

884 Records were Identified through database searching. 12 studies satisfied the inclusion criteria, resulting in MR features of 288 patients. All the studies were retrospective. Classic features of IPMN-B are under-described. Few studies note worrisome features, concerning for an underlying malignancy. 50 % of the studies had a high risk of bias and concerns regarding applicability.

Conclusions

The MRI features of IPMN-B are not well elaborated and need to be further studied. Worrisome features and guidelines regarding reporting the imaging findings should be established and published. Radiologists should be aware of IPMN-B, since malignancy diagnosis in an early stage will yield improved prognosis.

Imaging of Hepatobiliary Cancer

The liver and biliary tree are common sites of primary and secondary malignancies. MRI followed by CT is the mainstay for the imaging characterization of these malignancies with the dynamically acquired contrast enhanced phases being the most important for diagnosis. The liver imaging reporting and data system classification provides a useful framework for reporting lesions in patents with underlying cirrhosis or who are at high risk for developing hepatocellular carcinoma. Detection of metastases is improved with the use of liver specific MRI contrast agents and diffusion weighted sequences. Aside from hepatocellular carcinoma, which is often diagnosed noninvasively, other primary hepatobiliary tumors may require biopsy for definite diagnosis, especially when presenting with nonclassic imaging findings. In this review, we examine the imaging findings of common and less common hepatobiliary tumors.

Mucin-producing Cystic Hepatobiliary Neoplasms: Updated Nomenclature and Clinical, Pathologic, and Imaging Features

Cystic hepatobiliary neoplasms with mucin-producing epithelium-mucinous cystic neoplasm of the liver (MCN) and intraductal papillary neoplasm of the bile duct (IPNB)-are rare and distinct entities that have unique clinical, pathologic, and imaging features. They are differentiated pathologically by the presence of subepithelial ovarian-like hypercellular stroma (OLS), which is the defining histopathologic feature of MCN. MCN is commonly a benign, large, solitary, symptomatic, multiloculated cystic mass without biliary communication that occurs in middle-aged women. On the other hand, IPNBs are a heterogeneous spectrum of tumors, which are commonly associated with invasive carcinoma, occur in older patients, and can be differentiated from MCN by communication with the biliary tree, intraductal masses, associated biliary ductal dilatation, and absent OLS. Understanding of these rare neoplasms has grown and evolved over time and continues to today, but uncertainty and controversy persist, related to the rarity of these tumors, relatively recent designation as separate entities, inherent clinicopathologic heterogeneity, overlapping imaging features, and the fact that many prior studies likely included MCN and cystic IPNB together as a single entity. Confusion regarding these neoplasms is evident by historical inconsistencies and nonstandardized nomenclature through the years. Awareness of these entities is important for the interpreting radiologist to suggest a particular diagnosis or generate a meaningful differential diagnosis in the appropriate setting, and is of particular significance as MCN and cystic IPNB have overlapping imaging features with other more common hepatobiliary cystic masses but have different management and prognosis. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Clinicopathological findings and imaging features of intraductal papillary neoplasms in bile ducts

Background

Intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is considered an uncommon tumor, and there is limited understanding of IPMN-B. This study aimed to investigate the prognosis and influential factors of the IPMN-B from 58 cases.

Methods

The clinical data of 58 patients with pathologically confirmed IPMN-B admitted to our hospital from January 1, 2012 to August 2017 were collected and analyzed. The patients were followed up by outpatient or telephone until January 1, 2019. SPSS 19.0 software was applied for data analysis. Survival analysis was performed using Kaplan-Meier method and parallel Log-rank test. Prognostic factors were analyzed by univariate analysis and multiple Cox regression model.

Results

Among of all the patients, 26 cases were benign tumors and 32 cases were malignant tumors. The preoperative tumor markers CA242 and CEA of malignant IPNM-B patients were significantly higher than those in benign tumors (P < 0.05). Survival analysis showed that patients with malignant tumors had a worse prognosis. The median survival time of malignant IPMN-B patients was 40.6 ±  3.0 months, yet median survival time of benign IPMN-B patients was not reached (P = 0.19). The one-year survival rate and three-year survival rate of benign IPMN-B were 84% and 74% respectively. The one-year survival rate and three-year survival rate of malignant IPMN-B were 88% and 64% respectively. Univariate analysis showed that combined lymph node metastasis, surgical method, and differentiation degree could affect patients’ prognosis (P < 0.05). Multivariate analysis showed differentiation degree was an independent risk factor affecting prognosis (OR = 0.06, 95% confidence interval: 0.007∼0.486, P < 0.05).

Conclusion

The levels of CEA and CA242 were helpful to identify benign and malignant of IPNM-B. Moreover, radical surgical resection could prolong patients’ survival. Finally, differentiation degree was an independent risk factor affecting malignant IPNM-B prognosis.

Magnetic Resonance Imaging versus Computed Tomography for Biliary Tract Intraductal Papillary Mucinous Neoplasm (BT-IPMN): A Diagnostic Performance Analysis

BACKGROUND In most cases, biliary tract intraductal papillary mucinous neoplasm (BT-IPMN) is depicted by pathological features rather than on imaging modalities, but fine-needle aspiration cytology cannot provide complete information on tumor(s). Computed tomography (CT) has the advantage of high spatial resolution and multiplanar capabilities, while magnetic resonance imaging (MRI) has greater contrast resolution than CT. The purpose of this study was to compare the diagnostic performance of CT vs. MRI for the diagnosis of BT-IPMN using surgical pathology as the reference standard. MATERIAL AND METHODS Data from CT, MRI, and surgical pathology of 210 patients with complaints of abdominal discomfort, vomiting, and/or jaundice for at least 6 months were included in the analysis. Intra-observer agreements for diagnosis of neoplasm was evaluated by kappa statistics. RESULTS CT and MRI respectively detected 171 and 33 patients with BT-IPMN, 6 and 176 with biliary intraductal tubulopapillary neoplasms (BT-ITPN), and 28 and 6 with inconclusive results. Surgical pathology reported 179 patients with BT-IPMN and 25 patients with BT-ITPN. CT and MRI both had the same accuracy (97.14%) for BT-IPMN. The sensitivities for diagnosis of BT-IPMN were 87.75%, 83.81%, and 81.43% for the surgical pathology, MRI, and CT, respectively. Intra-observer agreements for diagnosis of neoplasm were substantial (k=0.79), perfect (k=0.81), and perfect (k=0.85) for CT, MRI, and surgical pathology, respectively. CONCLUSIONS MRI appears to be a more accurate and reliable method than CT for depicting BT-IPMN.

The combined use of EphA2/MMP-2 expression and MRI findings contributes to the determination of cerebral glioma grade

Glioma is the most aggressive brain tumor and is associated with a high mortality rate. The aim of the present study was to explore the association between matrix metalloproteinase 2 (MMP-2) and ephrin type-A receptor 2 (EphA2) expression in glioma cells, and to investigate the contribution of magnetic resonance imaging (MRI) in glioma classification. A total of 43 patients with pathologically confirmed glioma were divided into two groups as follows: Low-grade (grades I and II; n=21) and high-grade (grades IV and IV; n=22). Subsequently, immunohistochemistry staining was performed to detect the expression levels of MMP-2 and EphA2 in the low- and high-grade groups. MRI routine and enhanced scans were used to measure the peritumoral edema index (EI), tumor enhancement percentage (EP) and maximum tumor diameter. The results demonstrated that the proportion of MMP-2-positive patients in the high-grade group was 86.36% (19/22), which was significantly higher than that of the low-grade group (57.14%; 12/21) (P<0.05). Furthermore, the proportion of EphA2-positive patients in the high-grade group was 90.91% (20/22), significantly higher than that in the low-grade group (4.76%; 1/21) (P<0.01). In addition, the MRI results indicated that the EI, EP and maximum tumor diameter were significantly higher in the high-grade group compared with the low-grade group (P<0.01, P<0.01 and P<0.05, respectively). Finally, the expression levels of MMP-2 and EphA2 were significantly associated with the EI, EP and maximum tumor diameter (all P<0.05). In conclusion, the expression levels of MMP-2 and EphA2 were positively correlated with glioma invasion. The correlation between these expression levels and MRI assessment of the EI, EP and maximum tumor diameter indicated that the combination of these two methods may be used for the evaluation of the tumor grade and for further clinical treatment applications.

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.

Staging of liver fibrosis using Gd-EOB-DTPA and Gd-BOPTA enhanced magnetic resonance imaging

The severity of cirrhosis is closely related to its clinical treatment. Therefore, it is important to stage liver fibrosis accurately. Although liver biopsy can accurately stage the degree of cirrhosis, it has certain limitations in clinical application because of its invasive nature. Magnetic resonance imaging (MRI) has been used in the diagnosis of liver diseases. In recent years, two new contrast agents, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) and gadobenate dimeglumine (Gd-BOPTA), have been successfully used for noninvasive liver imaging. They can be used for liver fibrosis staging and assessment of liver function. Cirrhotic patients with different liver function levels have a statistical difference in the liver parenchyma enhancement after giving contrast agents. This article briefly summarizes the progress of Gd-EOB-DTPA and Gd-BOPTA enhanced MRI in staging liver fibrosis stage.

Morphological classification of intraductal papillary neoplasm of the bile duct

OBJECTIVES

To investigate the morphological classification of intraductal papillary neoplasm of the bile duct (IPNB), as well as morphological differences between IPNB without mucin secretion (IPNB-NM) and IPNB with mucin secretion (IPMN-B).

METHODS

Eighty-one patients with IPNB were retrospectively analysed. Imaging examinations included computed tomography (CT), magnetic resonance imaging (MRI), gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI and positron emission tomography-computed tomography (PET-CT). According to the morphology of tumours and extent of bile duct dilations, IPNB was classified into seven types: I, upstream-ductectatic type; II, typical type; III, superficial-spreading type; IV, no-mass-forming type; V, intrahepatic-cystic type; VI, extrahepatic-cystic type; and VII, infiltrating type.

RESULTS

Thirteen IPNB-NM patients comprised type I (11 cases), type II (1 case) and type VII (1 case); 68 IPMN-B patients comprised type I (2 cases), type II (30 cases), type III (6 cases), type IV (11 cases), type V (13 cases), type VI (2 cases) and type VII (4 cases). Bile duct dilations were more severe in IPMN-B than in IPNB-NM. PET-CT and Gd-EOB-DTPA-enhanced MRI clearly demonstrated the extension of infiltrating IPNB.

CONCLUSIONS

IPNB can be classified into seven morphological types. IPNB-NM and IPMN-B have different morphological features.

KEY POINTS

• IPNB can be classified into seven morphological types. • IPNB-NM and IPMN-B have different morphological features. • Enhanced CT and MRI can display different types of IPNB. • Morphological classification of IPNB facilitates management of the disease.

Comparative radiological pathological study of biliary intraductal tubulopapillary neoplasm and biliary intraductal papillary mucinous neoplasm

PURPOSE

Biliary tract intraductal tubulopapillary neoplasms (BT-ITPNs) and intraductal papillary mucinous neoplasms (BT-IPMNs) are rare and poorly described. Herein, we examined the magnetic resonance imaging (MRI) features of BT-ITPNs and BT-IPMNs and correlated them with key gross and microscopic pathological findings.

METHODS

We retrospectively identified five patients with definitive pathological findings of BT-ITPN and available diagnostic MRI findings. Key MRI features were correlated to the gross and microscopic pathology and compared to those of BT-IPMNs (19 patients).

RESULTS

All BT-ITPNs showed ductal dilatation and visible intraductal soft tissue with peribiliary liver parenchyma enhancement. One BT-ITPN patient had synchronous lung metastases, and another showed rapid tumor growth rate. The intraductal soft tissue proportion of BT-ITPNs was significantly more than that of BT-IPMNs (p < 0.05). CA-199 level was elevated in 60% of BT-ITPN cases. The overall combined 1-year and 3-year survival rates in the BT-ITPN group was 100% and 40%, and in the BT-IPMN group was 100% and 58%, respectively. A high intraductal soft tissue proportion, a lack of intraluminal mucin, and immunohistochemical absence of MUC5AC are radiological and pathological characteristics that differentiate BT-ITPN from BT-IPMN.

CONCLUSIONS

Although rare, BT-ITPN should be suspected when solid intraductal soft tissue and peribiliary liver parenchyma enhancement are present, particularly if the bile duct upstream and downstream of the lesion have a normal diameter, without mucin. Owing to the aggressive nature of the tumor, recognition of these features may indicate the need for more aggressive treatment in selected patients.