Enhancement characteristics of cholangiocarcinomas on mutiphasic helical CT: emphasis on morphologic subtypes

Cholangiocarcinoma imaging: from diagnosis to response assessment

Cholangiocarcinoma (CCA), a highly aggressive primary liver cancer arising from the bile duct epithelium, represents a substantial proportion of hepatobiliary malignancies, posing formidable challenges in diagnosis and treatment. Notably, the global incidence of intrahepatic CCA has seen a rise, necessitating a critical examination of diagnostic and management strategies, especially due to presence of close imaging mimics such as hepatocellular carcinoma (HCC) and combined hepatocellular carcinoma-cholangiocarcinoma (cHCC-CCA). Hence, it is imperative to understand the role of various imaging modalities such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), elucidating their strengths, and limitations in diagnostic precision and staging accuracy. Beyond conventional approaches, there is emerging significance of functional imaging tools including positron emission tomography (PET)-CT and diffusion-weighted (DW)-MRI, providing pivotal insights into diagnosis, therapeutic assessment, and prognostic evaluation. This comprehensive review explores the risk factors, classification, clinical features, and role of imaging in the holistic spectrum of diagnosis, staging, management, and restaging for CCA, hence serving as a valuable resource for radiologists evaluating CCA.

Imaging features based on CT and MRI for predicting prognosis of patients with intrahepatic cholangiocarcinoma: a single-center study and meta-analysis

BACKGROUND

To evaluate the prognostic role of imaging features based on CT and MRI in intrahepatic cholangiocarcinoma (ICC).

METHODS

Two hundred and four patients from a single-center database who underwent radical ICC surgery from 2010 to 2019 were enrolled in the study. Cox proportional hazard model was used for survival analysis of imaging features. A meta-analysis was performed to determine imaging features that predict overall survival (OS) and event-free survival (EFS) in ICC.

RESULTS

In the CT group of the retrospective cohort, tumor multiplicity, infiltrative tumor margin, lymph node metastasis, enhancement pattern in hepatic arterial phase and tumor necrosis correlated with poorer EFS and OS; moreover, enhancing capsules, high carcinoembryonic antigen levels contributed to poor OS. In the MRI group, tumor multiplicity and enhancement pattern were prognostic factors for OS; tumor multiplicity and enhancement pattern resulted in poor EFS. A total of 13 articles containing 1822 patients with ICC were enrolled in the adjusted hazard ratios meta-analysis. The results showed that enhancement pattern and infiltrative tumor margin were predictors of OS and EFS, whereas bile duct invasion was a predictor of OS.

CONCLUSIONS

Arterial enhancement patterns and tumor margin status were associated with both OS and EFS of ICC patients following resection.

New Imaging Techniques

The chapter discusses the advancement of new imaging techniques, the role of imaging in CCA diagnosis, anatomical and morphological classification, ultrasound screening of CCA, ultrasound findings of MF-CCA, PI-CCA, ID-CCA, the use of CT in CCA diagnosis, staging and treatment planning, CT volumetry and estimation of future liver remnant, post-treatment follow-up and surveillance, MRI imaging, Positron Emission Tomography (PET)/CT, limitations to contrast studies and resolution, internal receivers for CCA imaging, and in vitro imaging of CCA.

Clinical relevance of biomarkers in cholangiocarcinoma: critical revision and future directions

Cholangiocarcinoma (CCA) is a malignant tumour arising from the biliary system. In Europe, this tumour frequently presents as a sporadic cancer in patients without defined risk factors and is usually diagnosed at advanced stages with a consequent poor prognosis. Therefore, the identification of biomarkers represents an utmost need for patients with CCA. Numerous studies proposed a wide spectrum of biomarkers at tissue and molecular levels. With the present paper, a multidisciplinary group of experts within the European Network for the Study of Cholangiocarcinoma discusses the clinical role of tissue biomarkers and provides a selection based on their current relevance and potential applications in the framework of CCA. Recent advances are proposed by dividing biomarkers based on their potential role in diagnosis, prognosis and therapy response. Limitations of current biomarkers are also identified, together with specific promising areas (ie, artificial intelligence, patient-derived organoids, targeted therapy) where research should be focused to develop future biomarkers.

Can lymphovascular invasion be predicted by contrast-enhanced CT imaging features in patients with esophageal squamous cell carcinoma? A preliminary retrospective study

Background

To investigate the value of contrast-enhanced CT (CECT)-derived imaging features in predicting lymphovascular invasion (LVI) status in esophageal squamous cell carcinoma (ESCC) patients.

Methods

One hundred and ninety-seven patients with postoperative pathologically confirmed esophageal squamous cell carcinoma treated in our hospital between January 2017 and January 2019 were enrolled in our study, including fifty-nine patients with LVI and one hundred and thirty-eight patients without LVI. The CECT-derived imaging features of all patients were analyzed. The CECT-derived imaging features were divided into quantitative features and qualitative features. The quantitative features consisted of the CT attenuation value of the tumor (CTV_Tumor), the CT attenuation value of the normal esophageal wall (CTV_Normal), the CT attenuation value ratio of the tumor-to-normal esophageal wall (TNR), the CT attenuation value difference between the tumor and normal esophageal wall (ΔTN), the maximum thickness of the tumor measured by CECT (Thickness), the maximum length of the tumor measured by CECT (Length), and the gross tumor volume measured by CECT (GTV). The qualitative features consisted of an enhancement pattern, tumor margin, enlarged blood supply or drainage vessels to the tumor (EVFDT), and tumor necrosis. For the clinicopathological characteristics and CECT-derived imaging feature analysis, the chi-squared test was used for categorical variables, the Mann–Whitney U test was used for continuous variables with a nonnormal distribution, and the independent sample t-test was used for the continuous variables with a normal distribution. The trend test was used for ordinal variables. The association between LVI status and CECT-derived imaging features was analyzed by univariable logistic analysis, followed by multivariable logistic regression and receiver operating characteristic (ROC) curve analysis.

Results

The CTV_Tumor, TNR, ΔTN, Thickness, Length, and GTV in the group with LVI were higher than those in the group without LVI (P < 0.05). A higher proportion of patients with heterogeneous enhancement pattern, irregular tumor margin, EVFDT, and tumor necrosis were present in the group with LVI (P < 0.05). As revealed by the univariable logistic analysis, the CECT-derived imaging features, including CTV_Tumor, TNR, ΔTN and enhancement pattern, Thickness, Length, GTV, tumor margin, EVFDT, and tumor necrosis were associated with LVI status (P < 0.05). Only the TNR (OR 8.655; 95% CI 2.125–37.776), Thickness (OR 6.531; 95% CI 2.410–20.608), and tumor margin (OR 4.384; 95% CI 2.004–9.717) were independent risk factors for LVI in the multivariable logistic regression analysis. The ROC curve analysis incorporating the above three CECT-derived imaging features showed that the area under the curve obtained by the multivariable logistic regression model was 0.820 (95% CI 0.754–0.885).

Conclusion

The CECT-derived imaging features, including TNR, Thickness, tumor margin, and their combination, can be used as predictors of LVI status for patients with ESCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00804-7.

Role of noninvasive imaging in the evaluation of intrahepatic cholangiocarcinoma: from diagnosis and prognosis to treatment response

INTRODUCTION

Intrahepatic cholangiocarcinoma is the second most common liver cancer. Desmoplastic stroma may be revealed as distinctive histopathologic findings favoring intrahepatic cholangiocarcinoma. Meanwhile, a range of imaging manifestations is often accompanied with rich desmoplastic stroma in intrahepatic cholangiocarcinoma, which can indicate large bile duct ICC, and a higher level of cancer-associated fibroblasts with poor prognosis and weak treatment response.

AREAS COVERED

We provide a comprehensive review of current state-of-the-art and recent advances in the imaging evaluation for diagnosis, staging, prognosis and treatment response of intrahepatic cholangiocarcinoma. In addition, we discuss precursor lesions, cells of origin, molecular mutation, which would cause the different histological classification. Moreover, histological classification and tumor microenvironment, which are related to the proportion of desmoplastic stroma with many imaging manifestations, would be also discussed.

EXPERT OPINION

The diagnosis, prognosis, treatment response of intrahepatic cholangiocarcinoma may be revealed as the presence and the proportion of desmoplastic stroma with a range of imaging manifestations. With the utility of radiomics and artificial intelligence, imaging is helpful for ICC evaluation. Multicentre, large-scale, prospective studies with external validation are in need to develop comprehensive prediction models based on clinical data, imaging findings, genetic parameters, molecular, metabolic, and immune biomarkers.

MRCP Combined With CT Promotes the Differentiation of Benign and Malignant Distal Bile Duct Strictures

Objective

To determine whether contrast-enhanced computed tomography (CT) can promote the identification of malignant and benign distal biliary strictures (DBSs) compared to the use of magnetic resonance cholangiopancreatography (MRCP) alone and to identify imaging findings of malignant DBSs.

Materials and Methods

A total of 168 consecutive patients with confirmed DBSs were reviewed. MRCP alone and MRCP combined with CT images were blindly analyzed by two radiologists (e.g., stricture pattern, margins), and malignant or benign DBSs were identified based on surgical findings, endoscopy findings, or follow-up. The diagnostic accuracy of the two reviewers using MRCP alone and MRCP combined with CT were evaluated. MRCP and CT features of malignant and benign DBSs were compared using multiple logistic regression analysis to identify independent malignant risk factors.

Results

MRCP combined with CT examination could improve the diagnostic accuracy, which increased from 70.2% to 81.5% in Doctor A and from 85.1% to 89.3% in Doctor B. The multiple logistic regression model revealed that stricture length [odds ratio (OR) 1.070, P=0.016], angle of the DBS (OR 1.061, P<0.001), double duct sign (OR 4.312, P=0.003) and low density in the arterial phase (OR 0.319, P=0.018) were associated with malignant DBS. A scoring model incorporating these four factors was established; at a threshold value of 1.75, and the sensitivity and specificity for the detection of malignant DBSs were 73.5 and 85.9%, respectively.

Conclusions

Compared to the use of MRCP alone, MRCP combined with contrast-enhanced CT can improve the accuracy of DBS diagnosis. The scoring model accurately predicts malignant DBSs and helps make treatment decisions.

Cholangiocarcinoma: Part 1, Pathological and Morphological Subtypes, Spectrum of Imaging Appearances, Prognostic Factors and Staging

Cholangiocarcinoma (CC) is the most frequent malignant tumor of the biliary tract. The vast majority of cholangiocarcinomas are adenocarcinomas with a high proportion of fibrous stroma. Based on the macroscopic growth pattern, CC is classified as mass-forming, periductal infiltrating, or intraductal, with each type having its own characteristic imaging findings and prognostic outcome. The recently proposed pathological classification of cholangiocarcinoma into two types: perihilar large duct type and peripheral small duct and/or ductular type helps in better understanding of the morphology and the imaging appearances. Computed tomography (CT) and magnetic resonance imaging (MRI) remain the main tools of imaging. We aim to provide a comprehensive outline of the different subtypes and the rationale behind various imaging features of these subtypes. Cholangiocarcinoma is one of the more difficult tumors to treat and till date, surgery remains the only definitive curative treatment.

Gadoxetic acid magnetic-enhanced resonance imaging in the diagnosis of cholangiocarcinoma

The use of liver magnetic resonance imaging is increasing thanks to its multiparametric sequences that allow a better tissue characterization, and the use of hepatobiliary contrast agents. This review aims to evaluate gadoxetic acid enhanced magnetic resonance imaging in the diagnosis and staging of cholangiocarcinoma and its different clinical and radiological classifications proposed in the literature. We also analyze the epidemiology, risk factors in correlation with clinical findings and laboratory data.

Bile duct angulation and tumor vascularity are useful radiographic features for differentiating pancreatic head cancer and intrapancreatic bile duct cancer

BACKGROUND AND PURPOSE

To perform radical resection without leaving residual cancer, surgeons must distinguish between pancreatic head cancer (PHC) and intrapancreatic bile duct cancer (IPBDC) preoperatively. The aim of this study was to establish the points of difference between these two cancers, especially on preoperative multi-detector computed tomography (MDCT) images.

METHODS

The subjects of this study were 28 patients with PHC and proven bile duct invasion who underwent pancreatoduodenectomy (PHC group) and 22 patients with IPBDC and upstream bile duct dilation (IPBDC group). We compared the preoperative clinical and radiographic features, including the bile duct angle, calculated on coronal images of MDCT, and the vascularity of the tumor.

RESULTS

The optimal cut-off values for the bile duct angle, the CT value ratio of the tumor (late arterial phase/non-enhanced), and the main pancreatic duct (MPD) ratio (diameter of MPD/diameter of parenchyma) were 110°, 3.0, and 0.2, respectively. Multivariate analysis revealed that a bile duct angle < 110°, a CT value ratio of the tumor < 3, and an MPD ratio ≥ 0.2 were independently associated with PHC.

CONCLUSIONS

A bile duct angle and CT value reflecting the vascularity of the tumor might be useful radiographic features for differentiating PHC and IPBDC, in addition to MPD dilatation.

Cross-Sectional Imaging of Intrahepatic Cholangiocarcinoma: Development, Growth, Spread, and Prognosis

OBJECTIVE

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor that arises from the intrahepatic bile ducts. Although the pathologic and imaging features of ICC have been clearly identified, recent updates have addressed the pathologic classification and imaging features of ICC using new imaging techniques. First, a proposed new pathologic ICC subclassification includes perihilar large duct and peripheral small duct ICCs. Second, advanced MR-based imaging features of ICC, such as hepatobiliary phase imaging using hepatocytespecific contrast material and DWI, have recently been described. These imaging features are important when differentiating ICCs from hepatocellular carcinomas. Finally, some imaging features of ICC, such as prominent arterial enhancement or degree of delayed enhancement, exhibit potential as prognostic imaging biomarkers.

CONCLUSION

Comprehensive and updated knowledge of ICC is necessary for accurate diagnosis and could facilitate prediction of clinical outcomes for patients with ICC.

Multimodality imaging of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinomas account for approximately 20% of cases of cholangiocarcinomas. Three growth patterns or morphologic subtypes exist, including mass-forming, periductal-infiltrating, and intraductal-growth subtypes. Knowledge of these morphologic subtypes and their radiologic appearance aids in timely diagnosis, a key to optimizing patient outcomes. The morphologic variability of intrahepatic cholangiocarcinomas has a direct impact on the diagnostic sensitivity and specificity of various diagnostic imaging modalities, including ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP), and positron emission tomography (PET). The following review emphasizes optimal imaging technique for each of these modalities and reviews the imaging appearance of each morphologic subtype of intrahepatic cholangiocarcinoma.

Bile duct tumors

Bile duct tumors are benign or malignant lesions which may be associated to risk factors or potentially malignant lesions. They constitute an heterogenous entities group with a different biological behavior and prognosis according to location and growth pattern. We revise the role of the radiologist in order to detect, characterize and stage these tumors, specially the importance of their classification when deciding an appropriate management and treatment.

Imaging bile duct tumors: pathologic concepts, classification, and early tumor detection

Cholangiocarcinoma is the most common primary malignancy of the bile ducts which has several predisposing factors such as hepatolithiasis and primary sclerosing cholangitis, and can develop from precancerous conditions such as biliary intraepithelial neoplasia and intraductal papillary neoplasm of the bile duct. As surgical resection of early stage cholangiocarcinoma or precancerous lesions may provide better prognosis, early detection of those lesions is very important. Imaging studies play important roles in the diagnosis of bile duct tumors followed by appropriate management. Indeed, not only diagnosis of cholangiocarcinoma but also appropriate categorization of bile duct tumors based on their morphologic features and location on cross-sectional imaging studies, including computed tomography and magnetic resonance imaging, is important to predict their biologic behaviors, and choose relevant treatment strategies. We herein review the classification system of the bile duct tumors with their radiologic and pathologic findings as well as role of imaging in the early detection of bile duct tumors.

Intrahepatic cholangiocarcinoma: relationship between tumor imaging enhancement by measuring attenuation and clinicopathologic characteristics

PURPOSE

Arterial enhancement of intrahepatic cholangiocarcinoma (ICC) has been noted. To precisely identify the characteristics of tumor enhancement patterns, we examined the relationship between CT attenuation in the tumor and clinicopathological parameters or prognosis.

METHODS

Subjects were 42 ICC patients who had undergone hepatectomy. microvessel density (MVD) determined by CD34 staining was compared with imaging. Attenuation was calculated in images from multidetector CT of tumor and non-tumorous regions. Enhancement patterns were divided into two groups: arterial enhancement with higher attenuation (>16 HU; Hyper group, n = 12); and arterial enhancement with lower attenuation (Hypo group, n = 30).

RESULTS

Univariate analysis identified high tumor marker level, increased size, less-differentiation, incomplete resection, increased bleeding, and lower MVD as significantly associated with poor survival (p < 0.05). Increased attenuation throughout the whole ICC correlated significantly with radiological findings and MVD. Concomitant hepatitis, well-differentiation, and smaller tumor were more significantly frequent in the Hyper group than in the Hypo group (p < 0.05). Postoperative early recurrence was significantly less frequent in the Hyper group, and overall survival was significantly better in the Hyper group (p < 0.05).

CONCLUSIONS

Increased CT attenuation correlated with ICC tumor vascularity. Increased tumor enhancement in the arterial phase was associated with chronic hepatitis, lower malignancy, and better survival.

Differential diagnosis of sclerosing cholangitis with autoimmune pancreatitis and periductal infiltrating cancer in the common bile duct at dynamic CT, endoscopic retrograde cholangiography and MR cholangiography

OBJECTIVES

To compare findings at dynamic computed tomography (CT), endoscopic retrograde cholangiography (ERC) and magnetic resonance cholangiography (MRC) in patients with sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and periductal infiltrating cancer in the common bile duct (CBD), and to evaluate the diagnostic performance of ERC and MRC in differentiating between the two diseases.

METHODS

Bile duct changes at dynamic CT, ERC and MRC were compared in 58 patients with SC-AIP and CBD involvement and 93 patients with periductal infiltrating CBD cancer. Two radiologists rated their confidence in differentiating between the two diseases and the diagnostic performances of ERC and MRC were compared.

RESULTS

At CT, SC-AIP was more frequently associated with intrapancreatic CBD involvement, thinner CBD walls, concentric wall thickening, smooth outer margins, and lower degrees of upstream ductal dilatation and contrast enhancement (P ≤ 0.05) than CBD cancer. At ERC and MRC, SC-AIP was more frequently associated with smooth margins, gradual and symmetric narrowing, multifocal involvement and hourglass appearance (P ≤ 0.027) than CBD cancer. MRC showed good diagnostic performance comparable to ERC.

CONCLUSIONS

Dynamic CT, ERC and MRC can be helpful in distinguishing SC-AIP from periductal infiltrating CBD cancer. MRC may be a useful diagnostic alternative to ERC in differentiating between the two diseases.

KEY POINTS

• SC-AIP often mimics periductal infiltrating ductal cancer. • Imaging findings of SC-AIP and periductal infiltrating CBD cancer can be similar. • Dynamic CT, ERC and MRC help differentiate between these two diseases. • MRC may be a useful diagnostic alternative to ERC.

Correlations between MDCT features and clinicopathological findings of hepatic paragonimiasis

AIM

To illustrate the MDCT features of hepatic paragonimiasis and correlate the results with clinicopathological findings.

MATERIALS AND METHODS

Eighteen patients (8 male, 10 female; mean age 37years) with hepatic paragonimiasis were included in this study. MDCT features of their hepatic lesions were retrospectively reviewed and correlated with clinicopathological findings.

RESULTS

All patients were lifelong residents in endemic areas of paragonimiasis, especially Paragonimiasis skrjabini variety. Abdominal pain or discomfort, fever and high eosinophil percentage were the predominant clinical features. In total, 21 lesions were detected on MDCT images, 18 (85.7%) directly contacted the hepatic capsule and 3 (14.3%) were adjacent to the capsule. Segment V (26%), VIII (26%) and VI (18.5%) were the most commonly involved sites. Sixteen lesions (76%) were conglomerated cystic or multilocular and 5 (24%) were solid. On plain MDCT scan, the margin and internal detail of the lesions were not clear except for one cystic variety, while they were clearly demonstrated on enhanced images. Single or multiple cysts with different diameters were commonly detected in the non-solid lesions, and some of them were mutually connected with tortuous tract formation. Among the solid lesions, 2 and 3 showed tubular and homogeneous enhancement, respectively.

CONCLUSION

Peripherally distributed lesions, mutually connected cysts with tortuous tract formation, and tubular enhancement, which may be closely associated with the infection route and migration of the worm, could be seen as the main MDCT features of hepatic paragonimiasis.

Differentiation of intraductal growing-type cholangiocarcinomas from nodular-type cholangiocarcinomas at biliary MR imaging with MR cholangiography

PURPOSE

To describe the magnetic resonance (MR) findings of intraductal growing (IDG)-type cholangiocarcinoma (CC) and to identify the features that differentiate it from nodular-type CC.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived the informed consent requirement. Thirty-nine patients with pathologically proved IDG-type (n = 19) or nodular-type (n = 20) CCs who had undergone preoperative gadolinium-enhanced MR imaging with MR cholangiography were included in this study. Analysis of MR findings included determination of the (a) shape, enhancement degree, and pattern of the tumor; (b) outer caliber of the tumor-bearing segment; and (c) presence of tumor multiplicity, upstream and downstream bile duct dilatation, bile duct wall thickening adjacent to the tumor, and adjacent organ invasion. The significance of these findings was determined with the χ² test.

RESULTS

Significant features in the differentiation of IDG-type CCs from nodular-type CCs included papillary or irregular polypoid shape, lack of constriction of the tumor-bearing segment, hypoenhancement of the tumor to the liver during the equilibrium phase, tumor multiplicity, upstream and downstream bile duct dilatation, and no bile duct wall thickening adjacent to the tumor (P < .05). When at least two of these six imaging features were used in combination, sensitivity and specificity in the diagnosis of IDG-type CCs were 95% and 70%, respectively.

CONCLUSION

By using characteristic MR features, one can differentiate IDG-type CC from nodular-type CC with a high degree of accuracy at biliary MR imaging with MR cholangiography.

Differential CT features of intraductal biliary metastasis and double primary intraductal polypoid cholangiocarcinoma in patients with a history of extrabiliary malignancy

OBJECTIVE

The purpose of this study was to discern clinical and imaging features for differentiating intraductal metastasis from double primary intraductal cholangiocarcinoma in patients with a history of extrabiliary malignant disease.

MATERIALS AND METHODS

Over a 10-year period, the cases of 14 patients with histopathologically proven intraductal metastasis (n = 8) or double primary intraductal cholangiocarcinoma (n = 6) who had a history of extrabiliary malignancy were identified. Two radiologists retrospectively reviewed CT (n = 14) and MR (n = 6) images for the size and appearance of the intraductal lesion, presence of a parenchymal mass, multiplicity, attenuation on arterial and portal phase images, and presence of calcification. Clinical findings such as the location of extrabiliary malignancy and presence of Clonorchis sinensis infestation also were recorded. Univariate tests were used to differentiate the two disease entities.

RESULTS

Histopathologic confirmation was obtained by surgical resection (n = 12) or ultrasound-guided biopsy (n = 2). All intraductal metastatic lesions were of colorectal cancer, and all intraductal cholangiocarcinomas were associated with extracolonic malignant disease, including three cases of gastric cancer (p < 0.0001). All cholangiocarcinomas manifested themselves as purely intraductal masses, but five of the eight intraductal metastatic lesions were contiguous with parenchymal masses (p = 0.031). The appearance of the intraductal lesion was predominantly expansile in cases of metastasis (seven of eight cases) but not in cases of cholangiocarcinoma (one of six cases) (p = 0.026). Other findings were not statistically significant in differentiating the two disease entities.

CONCLUSION

When an intraductal lesion is found in a patient with extrabiliary malignancy, the presence of a contiguous parenchymal mass, an expansile nature of the intraductal lesion, and a history of colorectal cancer may suggest the presence of intraductal metastasis rather than double primary intraductal cholangiocarcinoma.

MR imaging findings of early bile duct cancer

PURPOSE

To retrospectively evaluate the MR imaging features of early bile duct cancer and to correlate them with the clinicopathologic findings.

MATERIALS AND METHODS

This retrospective study was approved by our institutional review board, and informed consent was waived. Seventeen patients with surgically proven early bile duct cancer who had undergone preoperative MR cholangiopancreatography with gadolinium-enhanced MR imaging, were included in this study. Two, experienced radiologists evaluated the MR images in consensus regarding the following findings: tumor number and morphology; signal intensity of the tumor; sharpness of the outer border of the bile duct wall; enhancement pattern of the tumor; and the presence of enlarged peribiliary lymph nodes. Another radiologist measured the SNR of the tumor and bile duct wall on gadolinium-enhanced MRI during the dynamic phases to evaluate the tumor enhancement degree.

RESULTS

In all patients, MR imaging demonstrated single or multiple intraluminal bile duct masses showing a sharply defined outer margin. The most common enhancement pattern of the biliary lesions showed heterogeneous amorphous enhancement or heterogeneous enhancement with central, dot-like structures or vascular structures (76.5%, 13/17 patients). The difference of SNR between bile duct and tumor was greatest in the equilibrium phase (P < 0.05).

CONCLUSION

MRCP combined with dynamic contrast-enhanced MRI can be useful for detecting early bile duct cancers. Common MR findings of early bile duct cancer include one or more inhomogeneously enhancing intraductal masses with clear outer margins and preservation of the bile duct wall.

Relationship between pattern of tumor enhancement and clinicopathologic characteristics in intrahepatic cholangiocarcinoma

AIM

Common enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on computed tomography (CT) is that of hypovascular enhancement; however, in some cases, tumor shows identical enhancement in the arterial phase to that in hepatocellular carcinoma. To identify the specific characteristics of different enhancement patterns, we examined the relationship between CT enhancement pattern and clinicopathological features or postoperative prognosis.

METHOD

Subjects were 43 consecutive ICC patients who had undergone hepatectomy. Enhancement patterns were divided into two types: hypovascular or delayed enhancement (Type A), and early enhancement in the arterial phase (Type B).

RESULTS

Type A enhancement was observed in 23 patients and Type B in 20. Accompanying chronic viral hepatitis was significantly more frequent in Type B than Type A. Well-differentiated adenocarcinoma was significantly more frequent in Type B than Type A. Multiple tumors were significantly more frequent in Type A than Type B. Japanese TNM stage I and II was more frequent in patients with Type B than those with Type A. Disease-free or overall survival was significantly better in patients with Type B than those with Type A.

CONCLUSION

Early enhancement in the arterial phase might be a useful indicator of lower malignant potential and better survival in ICC patients.