Imaging of intrahepatic cholangiocarcinoma: 1. Peripheral cholangiocarcinoma

Intrahepatic cholangiocarcinoma: pathogenesis, current staging, and radiological findings

To this date, it is a major oncological challenge to optimally diagnose, stage, and manage intrahepatic cholangiocarcinoma (ICC). Imaging can not only diagnose and stage ICC, but it can also guide management. Hence, imaging is indispensable in the management of ICC. In this article, we review the pathology, epidemiology, genetics, clinical presentation, staging, pathology, radiology, and treatment of ICC.

Role of liver biopsy in hepatocellular carcinoma

The role of liver biopsy in the diagnosis of hepatocellular carcinoma (HCC) has been challenged over time by the ability of imaging techniques to characterize liver lesions in patients with known cirrhosis. In fact, in the diagnostic algorithm for this tumor, histology is currently relegated to controversial cases. Furthermore, the risk of complications, such as tumor seeding and bleeding, as well as inadequate sampling have further limited the use of liver biopsy for HCC management. However, there is growing evidence of prognostic and therapeutic information available from microscopic and molecular analysis of HCC and, as the information content of the tissue sample increases, the advantages of liver biopsy might modify the current risk/benefit ratio. We herein review the role and potentiality of liver biopsy in the diagnosis and management of HCC. As the potentiality of precision medicine comes to the management of HCC, it will be crucial to have rapid pathways to define prognosis, and even treatment, by identifying the patients who could most benefit from target-driven therapies. All of the above reasons suggest that the current role of liver biopsy in the management of HCC needs substantial reconsideration.

Gadoxetic acid enhanced magnetic resonance imaging for prediction of the postoperative prognosis of intrahepatic mass-forming cholangiocarcinoma

PURPOSE

To identify imaging markers that independently predict the post-operative outcome of intrahepatic mass-forming cholangiocarcinoma (IMCC) using gadoxetate disodium-enhanced magnetic resonance imaging (MRI).

METHODS

Data from 54 patients who underwent pre-operative gadoxetate disodium-enhanced MRI and curative surgery for IMCC were retrospectively evaluated. The prognostic power of various imaging and pathological features reportedly associated with recurrence-free survival (RFS) and overall survival (OS) was analyzed using Cox regression models. A model combining imaging and pathological features was developed and its performance was evaluated using the Harrell C-index and Akaike information criterion.

RESULTS

Capsule penetration (P = 0.016) and tumor size (P = 0.015) were independent markers for worse RFS, while capsule penetration (P = 0.012) and hepatic vein obstruction (HVO, P = 0.016) were independent markers for worse OS, respectively, in the imaging-based model. Capsule penetration was the only imaging marker identified in the combined prediction model of RFS, and the combined model showed a higher C-index and lower AIC value compared with the model based on pathological features alone.

CONCLUSIONS

Capsule penetration and HVO on MRI are significantly worse imaging prognostic factors for post-operative outcomes in patients with IMCC. Incorporation of capsule penetration and HVO into a surgical staging system may improve prediction of the post-operative prognosis of IMCC.

Management of unresectable intrahepatic cholangiocarcinoma: how do we decide among the various liver-directed treatments?

Intrahepatic cholangiocarcinoma often causes death due to obstruction of the biliary system or interruption of the vascular supply of the liver. This fact emphasizes the critical need for local tumor control in this disease. Successful local tumor control has traditionally been achievable through surgical resection for the small proportion of patients with operable tumors. Technological advances in radiation oncology and in interventional radiology have enabled the delivery of ablative radiation doses or other cytotoxic therapies for tumors in the liver. In some cases, this has translated into substantial prolongation of life for patients with this disease, but the indications for these different treatment options are still the subject of ongoing debate. Here, we review the technological advances and clinical studies that are changing the way intrahepatic cholangiocarcinoma is managed, and discuss ways to achieve individualized treatment of patients.

Small intrahepatic peripheral cholangiocarcinomas as mimics of hepatocellular carcinoma in multiphasic CT

PURPOSE

Liver transplant guidelines for diagnosing hepatocellular carcinoma (HCC) do not mandate pathologic confirmation; instead, 'classic' imaging features alone are deemed satisfactory. Intrahepatic peripheral mass forming cholangiocarcinoma (IHPMCC) is a relative contraindication for transplantation due to high rate of recurrence and poor prognosis. This study examines the imaging findings of IHPMCC, to aid in the identification and differentiation from potentially confounding cases of HCC.

METHODS

After IRB approval, 43 tissue-proven cases of IHPMCC on multiphase CT were retrospectively reviewed by 2 fellowship-trained radiologists. Tumor size, presence of cirrhosis, tumor capsule, vascular invasion, tumor markers, and enhancement pattern were assessed. A grading system was assigned as determined by enhancement pattern to background liver on arterial, portal venous, and equilibrium phases, ranging from typical HCC to typical IHPMCC enhancement pattern.

RESULTS

Analysis based on our grading system shows 5 (11.6%) tumors demonstrating grade 1-2 enhancement, 9 (21%) grade 3-4 enhancement, and 29 (67.4%) grade 5 enhancement. Kruskal-Wallis test comparing CA19-9 between the five groups, Wilcoxin rank-sum test comparing tumor markers with presence or absence of tumor capsule, vascular invasion and cirrhosis, and nonparametric Pearson's correlation coefficient comparing tumor markers to tumor size were not statistically significant (p > 0.05).

CONCLUSION

Typical enhancement pattern of IHPMCC consisting of arterial phase hypoenhancement with progressive, centripetal-delayed enhancement is present in the majority of cases (68%). Five cases (11.7%) showed enhancement features potentially mimicking HCC, all of which are under 3.5 cm in size. Thus, small hyperenhancing lesions in a cirrhotic liver should be carefully scrutinized in light of differing therapy options from HCC, particularly in transplant situations.

MR imaging features of focal liver lesions in Wilson disease

Hepatic involvement in Wilson disease (WD) manifests as a diffuse chronic disease in the majority of patients. However, in a subset of patients focal liver lesions may develop, presenting with a wide range of imaging features. The majority of focal liver lesions in patients with WD are benign nodules, but there are reports that have described malignant liver tumors or dysplastic nodules in these patients. Because of the possibility of malignant transformation of liver nodules, major concerns have been raised with respect to the management and follow-up of patients with WD in whom focal liver lesions have been identified. The assessment of liver involvement in patients with WD is generally performed with ultrasonography. However, ultrasonography conveys limited specificity so that magnetic resonance (MR) imaging is often performed to improve lesion characterization. This review was performed to illustrate the spectrum of MR imaging features of focal liver lesions that develop in patients with WD. It is assumed that familiarity with the MR imaging presentation of focal liver lesions in WD may help clarify the actual nature of hepatic nodules in patients with this condition.

Recurrent Cardiac Tamponade: An Unusual Presentation of Intrahepatic Cholangiocarcinoma

A 48-year-old Egyptian woman presented with 8 months of sharp right upper chest pain and weight loss. She was discovered to have an enlarged cardiac silhouette on chest x-ray, and an echocardiogram revealed a large pericardial effusion with diastolic right atrial collapse. Pericardial window was done, and epithelial membrane antigen-positive neoplastic cells were identified in the pericardial fluid. Computed tomography showed a 6-cm hypermetabolic lesion on the liver segment IV, confirmed on biopsy to be a moderately differentiated adenocarcinoma consistent with intrahepatic cholangiocarcinoma.

Duration of Inflammatory Bowel Disease Is Associated With Increased Risk of Cholangiocarcinoma in Patients With Primary Sclerosing Cholangitis and IBD

OBJECTIVES

Primary sclerosing cholangitis (PSC) often coexists with inflammatory bowel disease (IBD) and can be complicated by cholangiocarcinoma (CCA), a lethal malignancy for which reliable predictors remain unknown. We aimed to characterize the influence of colectomy and IBD duration on risk of CCA in patients with PSC-IBD.

METHODS

A retrospective review of patients with PSC-IBD seen at the Mayo Clinic, Rochester, between January 2005 and May 2013 was performed. The primary outcome was time to development of CCA and our goal was to determine whether the risk differed between patients with and without colectomy. Risk factors were assessed using univariable and multivariable Cox proportional hazard models where colectomy, IBD disease duration, and development of advanced liver disease were treated as time-dependent covariates.

RESULTS

A total of 399 patients with PSC-IBD were included in the study, of whom 137 had a colectomy and 123 patients developed CCA. Age-adjusted univariate Cox proportional hazard models demonstrated that colectomy (hazard ratio (HR) 1.53, 95% confidence interval (CI) 1.05-2.22, P=0.02) and duration of IBD (HR 1.37, 95% CI 1.15-1.63, P<0.01) were associated with an increased risk of CCA, and colonic neoplasia (HR 1.52, 95% CI 0.97-2.37, P=0.06) and colectomy for colonic neoplasia (HR 1.62, 95% CI 1.01-2.61, P=0.05) approached significance. Among patients with a history of colectomy, colonic neoplasia as the indication for surgery was associated with a particularly increased risk of CCA (HR 2.91, 95% CI 1.24-6.84, P=0.01) compared with medically refractory disease. On multivariate analysis, duration of IBD remained significantly associated with CCA (HR 1.33, 95% CI 1.11-1.60, P<0.01). The influence of IBD duration on CCA risk was not modified after colectomy (P=0.69).

CONCLUSIONS

Prolonged duration of IBD is associated with an increased risk of CCA in patients with PSC-IBD, and colectomy itself does not modify this risk. These findings identify a subset of patients who are at high risk of this lethal complication and in need of close surveillance.

Mass-forming Intrahepatic Cholangiocarcinoma: Diffusion-weighted Imaging as a Preoperative Prognostic Marker

Purpose To assess the value of diffusion-weighted (DW) imaging as a prognostic marker in preoperative evaluation of patients with mass-forming intrahepatic cholangiocarcinoma (ICC). Materials and Methods This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. A total of 91 patients who underwent hepatic resection and DW imaging for mass-forming ICC were included. Two radiologists evaluated the degree of diffusion restriction of the tumors by using qualitative (visual) interpretation combined with quantitative analysis by volumetric evaluation of the whole tumor on DW images. Patients were classified into two groups: those in whom less than one-third of the tumor showed diffusion restriction (group 1) and those in whom more than one-third of the tumor showed diffusion restriction (group 2). Imaging findings in tumors were compared with pathology findings. Disease-free and overall survival rates were compared between the two groups by using the Kaplan-Meier method with the log-rank test. Results There were 43 patients in group 1 and 48 patients in group 2. The 1- and 3-year disease-free survival rates were 30% and 16%, respectively, in group 1 and 75% and 64%, respectively, in group 2 (P < .001). The 1- and 3-year overall survival rates were 77% and 26%, respectively, in group 1 and 92% and 67%, respectively, in group 2 (P = .001). Multivariate analysis revealed that diffusion restriction (P = .024), differentiation (P = .030), and intrahepatic metastasis (P = .001) were independent prognostic factors for overall survival. Conclusion The degree of diffusion restriction on DW images may be a prognostic marker in preoperative evaluation of patients with mass-forming ICC. (©) RSNA, 2016 Online supplemental material is available for this article.

[Radiological diagnosis of primary hepatic malignancy]

Modern radiology offers countless opportunities both in the detection but also in the characterization of primary liver malignancies. Ultrasound remains usually the first exploratory overview study whereat using ultrasound contrast agent for a further characterization of liver lesions improves this technique considerably. Advanced cross-sectional imaging methods can, in most cases, already provide an exact diagnosis. Thus, the CT is already considered a standard technique for liver imaging and magnetic resonance imaging has gained in recent years due to liver-specific contrast agents and faster sequences a central role in liver imaging. The following article provides an overview of these various radiological procedures and describes the different primary liver malignancies and their imaging characteristics.

Intrahepatic mass-forming cholangiocarcinoma: enhancement patterns on gadoxetic acid-enhanced MR images

PURPOSE

To evaluate the enhancement patterns of intrahepatic mass-forming cholangiocarcinomas (IMCCs) with emphasis on the hepatobiliary phase (HBP) of gadoxetic acid-enhanced magnetic resonance (MR) imaging.

MATERIALS AND METHODS

This retrospective study was institutional review board approved, and the requirement for informed consent was waived. Fifty patients (41 men, nine women; mean age, 62.3 years; range, 44-76 years) with IMCC underwent unenhanced and gadoxetic acid-enhanced T1- and T2-weighted MR imaging including dynamic phase and hepatobiliary phase imaging between May 2008 and December 2010. Signal intensity and enhancement patterns of lesions were compared with those of the liver parenchyma in each phase. Conspicuity and margin sharpness of lesions on dynamic phase and HBP images were rated on a 4- or 5-point scale and compared by using the Wilcoxon signed-rank test. Percentage of relative enhancement was compared among pathologic subgroups by using the unpaired Student t test.

RESULTS

On dynamic phase images, 29 of 48 (60%) lesions showed a thin peripheral rim with centripetal or gradual progression. On HBP images, 48 of 50 (96%) IMCCs were hypointense, and two of 50 (4%) were hyperintense. Subjective ratings of conspicuity and margin sharpness were significantly higher on HBP (median scores, 5 and 4, respectively) (P < .001) than on the dynamic phase (median scores, 4 and 3, respectively) images (P < .001). Additional daughter nodules were found in five patients and intrahepatic metastasis was found in one. Percentage of relative enhancement on HBP images was significantly higher in moderately differentiated (66.4% ± 42.1) than in poorly differentiated (36.84% ± 21.5) tumors (P = .039) and in patients without (59.7% ± 28.8) than in those with (24.9% ± 14.7) (P = .036) lymph node metastasis.

CONCLUSION

The most prevalent enhancement pattern on gadoxetic acid-enhanced MR images of IMCCs was a thin peripheral rim with internal heterogeneous enhancement during the dynamic phase. HBP images showed increased lesion conspicuity and better delineation of daughter nodules and intrahepatic metastasis, which may aid in the diagnosis of IMCC.

T2-weighted and diffusion-weighted MRI for discriminating benign from malignant focal liver lesions: diagnostic abilities of single versus combined interpretations

PURPOSE

To compare the diagnostic accuracies of diffusion-weighted imaging (DWI), T2-weighted imaging (T2WI), and the combination of both sequences in discriminating benign from malignant focal liver lesions (FLLs).

MATERIALS AND METHODS

In all, 166 patients with 269 FLLs (153 benign and 116 malignant) were retrospectively evaluated. Two abdominal readers visually assessed the DWI, T2WI, and the combined (DWI+T2WI) image sets in an independent and blinded manner. The diagnostic abilities of each image set in discriminating the benign from the malignant FLLs set were compared using a binary logistic regression model. Pathologic results, consensus reading, and follow-up imaging were used as the reference standard.

RESULTS

The overall characterization accuracy in all lesions of the combined set (80.3%) was significantly higher than those of the T2WI set (68.8%) and DWI set (73.2%) (combined vs. T2WI, P < 0.001; combined vs. DWI, P = 0.001), while there was no significant difference between the T2WI and DWI sets (P = 0.058). All image sets were more accurate in the characterization of malignant FLLs than of benign FLLs (P < 0.001).

CONCLUSION

T2WI and DWI are complementary in discriminating benign from malignant FLLs; their combination improves diagnostic confidence.

Value of contrast-enhanced sonography in the diagnosis of peripheral intrahepatic cholangiocarcinoma

BACKGROUND

To illustrate contrast-enhanced harmonic ultrasonography (CEUS) findings of peripheral intrahepatic cholangiocarcinoma (PICC) and to assess the usefulness of CEUS in the diagnosis of this disease.

METHODS

This study is a retrospective analysis of 46 patients (20 men, 26 women) with PICC who underwent both preoperative CEUS and pathologic examination. Sonographic examinations were performed with sonographic instruments equipped with low mechanical index contrast imaging software. The contrast agent SonoVue was used. The wash-in and wash-out features of the lesions were documented and the enhancement patterns were analyzed by visual inspection of the real-time cine loops.

RESULTS

During the hepatic arterial phase of CEUS, the majority of PICC lesions (43/46, 93.5%) showed hypervascularity compared with the liver parenchyma, whereas three lesions (3/46, 6.5%) showed hypovascularity. In the portal phases, all lesions were either isoechoic or hypoechoic, while they were all hypoechoic in the late phase. Of all the hypervascular lesions, 48.8% (21/43) showed diffuse enhancement and 51.2% (22/43) showed rim-like or thick, rim-like enhancement. In 62.8% (27/43) of cases, progressive dendritic and centripetal fill-in of the contrast agent was observed. There were 83.7% (36/43) of hypervascular nodules showing heterogeneous enhancement during peak contrast enhancement of the lesions. CEUS provided clearer visualization of lesion margins than did conventional sonography.

CONCLUSIONS

CEUS examination yields some specific findings that are useful in the diagnosis of PICC.

Gadoxetic acid disodium-enhanced hepatocyte phase MRI: can increasing the flip angle improve focal liver lesion detection?

PURPOSE

To determine whether hepatocyte phase gadoxetic acid disodium (EOB)-enhanced MRI using a high flip angle (FA) improves focal liver lesion (FLL) detection compared with using a standard low FA.

MATERIALS AND METHODS

Sixty-two consecutive patients with 159 FLLs underwent EOB-enhanced MRI during the hepatocyte phase at 5, 10, 15, and 20 min, with both low (10°) and high (30°) FAs. Two blinded radiologists independently and randomly reviewed the two image sets using a four-point rating scale. Sensitivities and specificities were calculated and lesion-to-liver contrast ratio (LLC) on all hepatocyte phase images was measured.

RESULTS

The sensitivities with high FA for small (≤10 mm) malignant FLLs were significantly higher than those with low FA, at all time points, for both readers (P ≤ 0.05). Meanwhile, the specificities of the two protocols for the detection of all FLLs at all time points during the hepatocyte phase were high and same (98.2%) for both readers, without any significant differences (P = 1.00). LLCs with high FA were significantly higher than those with low FA at all time points (P ≤ 0.001).

CONCLUSION

Hepatocyte phase EOB-enhanced MRI with increasing FA can significantly increase LLC and improve the detection of FLLs, particularly small malignant lesions.

Enhancement patterns of intrahepatic cholangiocarcinoma: comparison between contrast-enhanced ultrasound and contrast-enhanced CT

The aim of this study was to compare the enhancement pattern of intrahepatic cholangiocarcinoma (ICC) on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). 40 pathologically proven ICC lesions in 40 patients were evaluated retrospectively with both CEUS and CECT. The enhancement level and pattern in the dynamic phases on both CEUS and CECT were analysed. The diagnostic results of CEUS and CECT before pathological examination were also recorded. During arterial phases, the number of lesions that appeared as (i) peripheral irregular rim-like hyperenhancement, (ii) diffuse heterogeneous hyperenhancement, (iii) diffuse homogeneous hyperenhancement and (iv) diffuse heterogeneous hypoenhancement were 19 (47.5%), 9 (22.5%), 5 (12.5%) and 7 (17.5%), respectively, on CEUS, and 22 (55.0%), 3 (7.5%), 2 (5.0%) and 13 (32.5%), respectively, on CECT (p = 0.125). In the portal phase, the number of lesions showing hyperenhancement and hypoenhancement were 1 (2.5%) and 39 (97.5%), respectively, on CEUS, and 15 (37.5%) and 25 (62.5%) on CECT (p = 0.0001). CEUS made a correct diagnosis in 32 (80.0%) lesions before pathological examination; CECT made a correct diagnosis in 27 (67.5%) lesions (p = 0.18). In conclusion, the enhancement patterns of ICC on CEUS were consistent with those on CECT in the arterial phase, whereas in the portal phase ICC faded out more obviously on CEUS than on CECT. CEUS had the same accuracy as CECT in diagnosing ICCs, and so can be used as a new modality for the characterization of ICC.

Primary Cancer of the Liver and Biliary Duct

F-18-FDG PET and PET/CT are useful for staging, predicting the prognosis, and evaluating recurrence and treatment response in hepatocellular carcinomas (HCCs) and cholangiocarcinomas. Increased F-18-FDG uptake within tumors could be a surrogate marker of aggressive behavior and poor clinical outcome, despite high false-negative rates in detecting primary intrahepatic low-grade HCCs and periductal-infiltrating cholangiocarcinomas. Dualtracer PET or PET/CT using carbon-11-acetate and F-18-FDG will increase diagnostic performance in HCC.

The multidisciplinary management of gastrointestinal cancer. The diagnostic and therapeutic approach for primary solid liver tumours in adults

The finding of a focal solid liver lesion represents a challenge for the clinician in terms of the most optimal diagnostic and therapeutic algorithm. Tumours may arise from hepatocytes (hepatocellular adenoma, dysplastic nodules and carcinoma), bile ducts (cholangiocarcinoma) or mesenchymal tissue (hemangioma, epithelioid haemangioendothelioma), or are metastases from primary tumours outside the liver. Focal nodular hyperplasia is the most frequent tumour-like lesion. Imaging techniques are able to detect and characterise most lesions. However, small hypervascular lesions in a cirrhotic liver may be difficult to characterise. More insight has been gathered recently in the histological classification of hepatocellular adenomas, but the differential diagnosis by imaging of adenoma versus FNH or well-differentiated hepatocellular carcinoma remains often difficult. The therapy of a focal liver lesion is determined by its natural history and the functional status of the surrounding liver parenchyma. Selected patients with primary liver cancer are candidates for liver transplantation, while patients with advanced malignant tumours have a poor outcome.

Liver metastases: imaging considerations for protocol development with multislice CT (MSCT)

Conventional, single-slice helical computed tomography (SSCT) allowed for scanning the majority of the liver during the critical portal venous phase. This was often referred to as the ‘optimal temporal window’. The introduction of current day multislice CT (MSCT) now allows us to acquire images in a much shorter time and more precisely than ever before. This yields increased conspicuity between low attenuation lesions and the enhanced normal liver parenchyma and optimal imaging for the vast majority of hepatic hypovascular metastases. Most importantly, these scanners, when compared to conventional non-helical scanners, avoid impinging upon the ‘equilibrium’ phase when tumors can become isodense/invisible. MSCT also allows for true multiphase scanning during the arterial and late arterial phases for detection of hypervascular metastases. The MSCT imaging speed has increased significantly over the past years with the introduction of 32- and 64-detector systems and will continue to increase in the future volumetric CT. This provides a number of important gains that are discussed in detail.

Imaging of peripheral cholangiocarcinoma with low-mechanical index contrast-enhanced sonography and SonoVue: initial experience

OBJECTIVE

The purpose of this study was to investigate the imaging findings of peripheral cholangiocarcinoma with low-mechanical index (MI) contrast-enhanced sonography.

METHODS

Eighteen nodules of peripheral cholangiocarcinoma proved by pathologic examination in 18 patients were evaluated with contrast-enhanced sonography. A low-MI real-time contrast-enhanced sonographic mode (ie, contrast pulse sequencing) and a sulfur hexafluoride-filled microbubble contrast agent (SonoVue [BR1]; Bracco SpA, Milan, Italy) were used.

RESULTS

On contrast-enhanced sonographic images, all 18 nodules (100%) of peripheral cholangiocarcinoma showed inhomogeneous enhancement during the arterial phase, and the emergence of nodule enhancement was earlier in 3 nodules (16.7%), simultaneous in 13 (72.2%), and later in 2 (11.1%), respectively, when compared with the adjacent liver tissue. During the arterial phase, 8 nodules (44.4%) showed irregular peripheral rimlike hyperenhancement, 2 (11.1%) showed inhomogeneous hyperenhancement, and 8 (44.4%) showed inhomogeneous hypoenhancement. In portal and late phases, all 18 nodules (100%) showed hypoenhancement. When contrast-enhanced sonography was added for analysis, the confidence levels of the investigators were improved in 15 (83.3%) of 18 nodules, and 17 (94.4%) of 18 peripheral cholangiocarcinomas were correctly characterized.

CONCLUSIONS

The imaging findings of peripheral cholangiocarcinoma had some characteristics on low-MI contrast-enhanced sonography. Knowledge of these characteristics might be beneficial for improving the diagnostic performance of sonography in evaluating this entity.

Clonorchiasis and cholangiocarcinoma: etiologic relationship and imaging diagnosis

Despite a gradual decrease in prevalence, clonorchiasis is still prevalent in East Asia. A large and compelling body of evidence links clonorchiasis and cholangiocarcinoma, although the mechanisms involved are not completely understood. Clonorchiasis induces biliary epithelial hyperplasia and metaplasia, and this could facilitate at least one stage of the carcinogenesis, which is promoting effect. In areas of endemic infection, more clonorchiasis cases are now diagnosed incidentally during radiological examinations such as cholangiography, ultrasonography, and computed tomography. Radiological findings are regarded as pathognomonic for clonorchiasis since they reflect the unique pathological changes of this disorder. These radiological examinations currently play important roles in the diagnosis, staging, and decision-making process involved in the treatment of cholangiocarcinoma. The morphological features and radiological findings of clonorchiasis-associated cholangiocarcinoma are essentially combinations of the findings for the two diseases. The morphological features of clonorchiasis- associated cholangiocarcinoma, observed in radiological examinations, do not differ from those of the usual cholangiocarcinoma. In patients diagnosed with or suspected to have clonorchiasis, radiological findings should be carefully scrutinized for occult cholangiocarcinoma.

Magnetic Resonance Imaging of cholangiocarcinoma

Preoperative imaging with MRI/MRA/MRCP is an accurate non-invasive method for staging cholangiocarcinoma, and determining resectability. It provides information regarding tumor size, extent of bile duct involvement, vascular patency, extrahepatic extension, nodal or distant metastases, and the presence of lobar atrophy. MRCP is better for demonstrating bile ducts distal to the stricture, although with ERCP, therapeutic intervention such as stent placement and biopsy can be performed.

Usefulness of 18F-FDG PET in intrahepatic cholangiocarcinoma

Surgical resection is the only curative treatment strategy for intrahepatic cholangiocarcinoma (CC). Therefore, accurate staging is essential for appropriate management of patients with CC. We assessed the usefulness of 2-[(18)F]fluoro-2-deoxy- d-glucose (FDG) positron emission tomography (PET) in the staging of CC. We undertook a retrospective review of FDG PET images in 21 patients (10 female, 11 male; mean age 57 years) diagnosed with CC. Ten patients had hilar CC and 11, peripheral CC. Patients underwent abdominal magnetic resonance imaging (MRI) ( n=20) and computed tomography (CT) ( n=12) for the evaluation of primary tumours, and chest radiography and whole-body bone scintigraphy for work-up of distant metastases. For semi-quantitative analysis, the maximum voxel standardised uptake value (SUV(max)) was obtained from the primary tumour. All peripheral CCs showed intensely increased FDG uptake, and some demonstrated ring-shaped uptake corresponding to peripheral rim enhancement on CT and/or MRI. In nine of the ten patients, hilar CCs demonstrated increased FDG uptake of a focal nodular or linear branching appearance. The remaining case was false negative on FDG PET. One patient with a false negative result on MRI demonstrated increased uptake on FDG PET. Among the ten hilar CCs, FDG uptake was intense in only two patients and was slightly higher than that of the hepatic parenchyma in the remaining patients. For the detection of lymph node metastasis, FDG PET and CT/MRI were concordant in 16 patients, and discordant in five (FDG PET was positive in three, and CT and MRI in two). FDG PET identified unsuspected distant metastases in four of the 21 patients; all of these patients had peripheral CC. FDG PET is useful in detecting the primary lesion in both hilar and peripheral CC and is of value in discovering unsuspected distant metastases in patients with peripheral CC. FDG PET could be useful in cases of suspected hilar CC with non-confirmatory biopsy and radiological findings.

Multislice CT in imaging the liver

The objective of this paper is to address the dramatic impact of multislice CT (MSCT) in imaging the liver. Standard helical (spiral) CT has finally allowed for scanning the majority of the liver during the critical portal venous phase (PVP). This is often referred to as the ‘optimal temporal window’. In general, it occurs following a 70 s scan delay and is coincidental with the maximal delivery of contrast via the portal vein that provides 80% of the hepatic blood supply. This yields maximal conspicuity between low-attenuation lesions and the dramatically enhanced normal liver parenchyma at routine injection rates of 2–3 ml/s. Most importantly, these scanners, when compared to single-slice scanners, avoid impinging on the ‘equilibrium’ phase where tumors can become isodense/invisible. The introduction of MSCT with four, eight and 16-detector systems has significantly increased imaging speed. Volumetric CT will continue to increase speed in the future. This provides a number of important gains that will be described.

MR cholangiopancreatography

Although MRCP is still an evolving technique, it has established itself as clinically useful and comparable with ERCP for the evaluation of various biliary or pancreatic ductal diseases. MRCP is not only comparable with ERCP in its diagnostic ability, but it has the tremendous advantage of being noninvasive. Furthermore, MR imaging is useful in patients with incomplete or failed ERCP, and in patients with certain biliary or gastrointestinal surgical procedures it is the imaging modality of choice. ERCP will remain an extremely important modality because of the great clinical importance for interventional biliary procedures with this technique. Nonetheless, MRCP may in the near future replace most of the diagnostic imaging of the biliary tree, with diagnostic results even more improved with further developments of hardware and technique.

Imaging the spectrum of biliary tract disease

An understanding of underlying biliary pathology and the corresponding subtle changes reflected at imaging can greatly improve imaging accuracy in evaluating the biliary tract. The optimal demonstration of biliary tract imaging findings requires attention to specific imaging and contrast techniques, regardless of the modality used.

Hepatic neoplasms: computed tomography and magnetic resonance features

Over the last decade, major advances in computed tomography and magnetic resonance technology have occurred. These advances enable accurate, noninvasive detection and characterization of many hepatic neoplasms. This article illustrates the role of imaging in the evaluation of hepatic neoplasms and reviews the typical imaging features of both benign and malignant hepatic tumors. Benign tumors discussed include hemangiomas, focal nodular hyperplasia, hepatocellular adenoma, and simple cysts, as well as cysts associated with polycystic liver disease. Malignant neoplasms reviewed include metastases and conventional hepatocellular carcinoma as well as less common tumors such as fibrolamellar hepatocellular carcinoma, intrahepatic cholangiocarcinoma, angiosarcoma, and epithelioid hemangioendothelioma.

Arterial chemoinfusion therapy through an implanted port system for patients with unresectable intrahepatic cholangiocarcinoma--initial experience

Arterial chemoinfusion therapy through an implanted port system was performed for patients with unresectable intrahepatic cholangiocarcinoma (ICC). Eleven patients with unresectable ICC were studied. Seven patients had stage-IV disease, two had stage-III disease, and two had stage-II disease. The mean tumor size was 7.0+/-2.6 cm (range 3.8-13.5 cm). A catheter and port system was percutaneously implanted, and anticancer drugs featuring fluorouracil were administered via the infusion system every 1-2 weeks on the outpatient basis in all patients except 2. Arterial chemoinfusion therapy was repeated 12-84 times per patient (mean 51 times). Partial and minor responses were achieved in sevenents (64%). Disease was stable in two patients (18%), and progressed in the other two patients (18%). Tumor growth was controlled during a mean period of 14.5 months in seven responders and two patients with stable disease. The survival rates were 91% at 1 year, 51% at 2 years, 20% at 3 years, and 10% at 4 years, respectively. The mean survival period was 26 months. Toxicity such as cholangitis and pancytopenia was found in three patients (27%). This treatment seems to improve the prognosis of patients with unresectable ICC and deserves further studies.

Radiologic spectrum of cholangiocarcinoma: emphasis on unusual manifestations and differential diagnoses

Most cholangiocarcinomas are ductal adenocarcinomas that arise from both intra- and extrahepatic bile duct epithelium, and their typical growth pattern can be classified as exophytic, infiltrative, polypoid, or a combination of these. Those of unusual histologic type (eg, mucin-hypersecreting cholangiocarcinoma, squamous adenocarcinoma, biliary cystadenocarcinoma, and mucinous carcinoma) show a growth pattern different from that of the typical ones (ie, ductal). Cholangiocarcinomas frequently develop in patients with any of a variety of preexisting bile duct diseases, some of which are considered precursors of cholangiocarcinoma (eg, biliary lithiasis, clonorchiasis, recurrent pyogenic cholangitis, and primary sclerosing cholangitis). Some bulky hepatic tumors of either primary or secondary origin mimic exophytic peripheral cholangiocarcinoma. Some variants of hepatocellular carcinoma, such as sclerosing, fibrolamellar, and cholangiohepatocellular carcinoma, resemble exophytic peripheral cholangiocarcinoma, while that with intraductal growth resembles polypoid cholangiocarcinoma. Among benign bile duct diseases, tumorous conditions (eg, benign biliary tumors) may mimic polypoid cholangiocarcinoma, whereas benign stricture of various causes (eg, cholangitides, traumatic and postsurgical sequelae, chronic pancreatitis, papillary stenosis) usually mimics infiltrative cholangiocarcinoma.

Hepatic capsular retraction: unusual finding of cavernous hemangioma

We report a case of hepatic giant hemangioma, which showed hepatic capsular retraction on CT and MRI. Pathologic examination revealed fibrosis combined with hemangioma, especially in a subcapsular location, which was responsible for the capsular retraction.

Retrospective analysis of prognostic factors after liver resection and transplantation for cholangiocellular carcinoma

BACKGROUND

Cholangiocellular carcinoma is an uncommon primary liver cancer, which may be mixed with hepatocellular carcinoma. A retrospective analysis was undertaken to evaluate the results of surgical treatment and to identify prognostic factors.

METHODS

Between 1978 and 1996, 162 patients underwent surgery for cholangiocellular carcinoma: liver resection (n = 95), liver transplantation (n = 24) and exploratory laparotomy with and without drainage (n = 43). Univariate and multivariate analyses of prognostic factors were performed.

RESULTS

Overall survival was 47 per cent at 1 year, 28 per cent at 2 years and 13 per cent at 5 years. Survival rates for patients with resectable tumours were 64, 43 and 21 per cent respectively, and for those who underwent liver transplantation 21, 8 per cent and zero respectively. Univariate analysis showed that the following variables had an effect on survival: age, jaundice, liver resection, T, N and M stage in the tumour node metastasis classification, Union Internacional Contra la Cancrum (UICC) tumour stage, tumour-free margins, vascular infiltration, tumour number, tumour size and serum level of carcinoembryonic antigen. Multivariate analysis identified jaundice, N and M category, and UICC tumour stage as independent prognostic factors.

CONCLUSION

The data underscore the importance and prognostic value of the UICC tumour classification for cholangiocellular carcinoma. The prognosis of mixed tumours is no different. Liver resection remains the treatment of choice; transplantation offers no solution for otherwise unresectable tumours.

Incidence of primary cholangiocellular carcinoma of the liver in japanese patients with hepatitis C virus-related cirrhosis

BACKGROUND

Hepatitis C virus (HCV) infection is a major risk factor for the development of hepatocellular carcinoma. However, the risk factors for primary cholangiocellular carcinoma of the liver (PCC-L) have not been fully investigated. The authors determined the incidence of PCC-L in patients with HCV-related cirrhosis.

METHODS

Between 1980 and 1997, the authors prospectively studied 600 consecutive patients for the appearance of PCC-L; these patients were positive for HCV and later developed cirrhosis. The follow-up period ranged from 0 to 18.5 years (median, 7.2 years).

RESULTS

During the observation period, PCC-L developed in 14 patients (2.3%). Among these, 11 (1.8%) had cholangiocellular carcinomas and the other 3 (0.5%) had a combined type of hepatocellular and cholangiocellular carcinoma. Within the same period, hepatocellular carcinoma (HCC) developed in 206 patients (34.3%). The cumulative rates of newly diagnosed PCC-L were 1.6% at 5 years and 3.5% at 10 years, which was about 1000 times higher than the estimated incidence of PCC-L in the general population of Japan. PCC-L was treated by surgical resection in 3 patients who survived for > 3 years. However, the other 11 patients received palliative therapy or chemotherapy. The survival rates among PCC-L patients were 39.3%, 23. 6%, and 16.5% at the end of 1, 3, and 5 years, respectively, and were significantly lower than those of HCC (P = 0.0001).

CONCLUSIONS

The results of this study show a relatively high incidence of PCC-L in patients with HCV-related cirrhosis, and also show that this type of liver cancer is associated with a relatively poor prognosis. These results indicate that HCV-related cirrhosis is a major risk factor for PCC-L in Japanese patients.

Biliary obstruction: findings at MR cholangiography and cross-sectional MR imaging

Twenty-two patients with malignant biliary obstruction and 21 patients with suspected obstruction of biliary-enteric anastomoses were evaluated over a 12-month period with magnetic resonance (MR) cholangiography and cross-sectional MR imaging. In patients with malignant obstruction, MR cholangiography helped accurately determine the status of the biliary ductal system by identifying the exact location and extent of the obstruction and the severity of duct dilatation. In so doing, MR cholangiography helped determine whether percutaneous transhepatic cholangiography with antegrade stent placement or retrograde cholangiography with stent placement constituted the more suitable treatment. Cross-sectional MR imaging was necessary to identify the organ of tumor origin, define the tumor margins, and determine the stage of disease. This information helped evaluate the appropriateness of curative surgical therapy versus palliative drainage procedures. In patients with biliary-enteric anastomoses, MR cholangiography clearly depicted the site of the anastomosis and demonstrated the status of the intrahepatic ducts, thereby helping determine which patients would benefit from undergoing antegrade duct cannulation with a drainage procedure or perhaps balloon dilation. In some of these patients, MR cholangiography was sufficient to help plan therapeutic intervention. MR cholangiography also demonstrates the presence and size of biliary stones and associated findings such as intraductal tumor growth. In addition, MR cholangiography may obviate retrograde cholangiography, which can be technically difficult to perform.

Intrahepatic peripheral cholangiocarcinoma: comparison of dynamic CT and dynamic MRI

PURPOSE

The purpose of this work was to compare dynamic MRI (D-MRI) with dynamic CT (D-CT) for the diagnosis of peripheral cholangiocarcinoma (PCC) of the liver.

METHOD

Twenty patients with PCC underwent both D-CT and D-MRI during the early, middle, and delayed phase after contrast medium administration. The findings from D-MRI were compared with those from D-CT.

RESULTS

D-CT and D-MRI exhibited a similar tumoral enhancement pattern, and this enhancement was more conspicuous on D-MRI. A wedge-like enhancement area peripheral to the tumor was observed in 9 (45%) patients on D-CT and 11 (55%) patients on D-MRI. Ductal dilatation was found in 13 (65%) patients on both techniques. Vascular involvement and extrahepatic invasion were seen in nine (45%) and two (10%) patients, respectively. The relationship of the tumor to the vessels and surrounding organs was more easily evaluated on D-CT.

CONCLUSION

Both D-CT and D-MRI can provide important information for the diagnosis of PCC. D-CT is better than D-MRI for demonstrating vascular involvement and extrahepatic invasion. D-MRI gives more conspicuous enhancement.

Cholangiocarcinoma: spectrum of appearances on MR images using current techniques

This study describes the spectrum of appearances of cholangiocarcinoma on magnetic resonance (MR) sequences, including gadolinium-enhanced, fat-suppressed spoiled gradient echo images and MR cholangiography. Fifteen patients were included in the study. Histologic diagnosis was established in 11 patients by surgical resection (6 patients), percutaneous biopsy (4 patients), and open liver biopsy (1 patient). The final diagnosis was determined by correlation of the MR findings with cholangiographic studies and laboratory studies in 4 patients. MR studies were performed at 1.5 T, and the following sequences were obtained: T1-weighted spoiled gradient echo (SGE), T1-weighted fat-suppressed spin echo or SGE, T2-weighted fat-suppressed conventional or turbo spin echo, MR cholangiography, and gadolinium-enhanced T1-weighted fat-suppressed SGE images. The following determinations were made: tumor location, tumor extent, ductal dilatation, ductal wall thickness, signal intensity, enhancement pattern, and associated findings. Mass-like neoplasms were peripheral (6 patients), hilar (1 patient), and extrahepatic (2 patients). Circumferential tumors were hilar (2 patients) and extrahepatic (4 patients). All peripheral tumors were multifocal. Mass-like tumors were well-defined, rounded, and ranged from 1 to 14 cm in diameter. Circumferential tumors had less well-defined margins and measured from 3 to 15 mm in thickness. All mass-like tumors were moderately hypointense on T1-weighted images and mildly to moderately hyperintense on T2-weighted images. The circumferential tumors were iso- to moderately hypointense on T1-weighted images and iso- to mildly hyperintense on T2-weighted images. Mass-like tumors were generally well shown on non-contrast and immediate gadolinium-enhanced images, whereas circumferential tumors were poorly seen on non-contrast images and best shown on gadolinium-enhanced T1-weighted fat-suppressed images. The degree of enhancement ranged from minimal to intense on immediate gadolinium-enhanced images, with all tumors becoming more homogeneous in signal intensity on images obtained between 1 and 5 min following contrast administration. Tumor-containing lymph nodes greater than or equal to 1 cm in diameter were demonstrated in 11 out of 15 patients (73.3%). These were best shown on T2-weighted fat-suppressed images and gadolinium-enhanced fat-suppressed SGE images. MR cholangiography demonstrated the level of obstruction and degree of dilatation of the proximal biliary system in 5 out of 6 patients who underwent MR cholangiography. The spectrum of appearances of cholangiocarcinoma is demonstrable on MR images. Mass-like tumors are well shown on both pre- and post-gadolinium sequences. Circumferential tumors may cause minimally increased duct wall thickness and are most clearly shown on gadolinium-enhanced fat-suppressed SGE images obtained 1 to 5 min following gadolinium administration.

Magnetic resonance imaging of focal and diffuse hepatic disease

MRI is a powerful tool in the detection and characterization of both focal and diffuse liver pathology. Because of superior soft tissue characterization, direct multi-planar capabilities and lack of ionizing radiation, current state of the art MRI is useful when contrast CT is relatively contraindicated or not definitive. This article reviews the MRI findings of the most common focal and diffuse liver diseases encountered in clinical practice. Reviews of current MR techniques and MR contrast agents used in liver imaging have been recently published. For this article, discussion of specific techniques and use of contrast is addressed for each pathological entity discussed.

A western surgical experience of peripheral cholangiocarcinoma

The aim of this retrospective study was to analyse outcome in 31 European patients operated on for peripheral cholangiocarcinoma between 1988 and 1995 (hilar cholangiocarcinoma was excluded). Before 1992, in addition to conventional resection, patients with irresectable tumour and with no extrahepatic metastasis underwent total hepatectomy with liver transplantation. Mild abdominal pain was the most frequent presenting clinical sign (11 of 31 patients) and jaundice was present in only four patients. Preoperative histological findings were available for 20 patients but the diagnosis was correct in only eight of these. Nineteen patients had curative surgery: 17 underwent conventional resection and two had total hepatectomy with liver transplantation. Major hepatectomy was performed in 12 of 17 cases, extended to the caudate lobe in five, to the bile duct confluence in four and to the retrohepatic vena cava in one. Postoperative mortality and morbidity rates were three and seven of 19 patients respectively, median survival was 15 months, and actuarial 1-, 2- and 5-year survival rates were 67, 40 and 32 per cent respectively. Twelve patients had only exploratory laparotomy because of the presence of extrahepatic metastasis or irresectable tumour. The invasive nature of peripheral cholangiocarcinoma can explain the limited number of resectable cases and the particularly unfavourable prognosis. Total hepatectomy does not provide survival benefit. Conventional surgery remains the only effective treatment, even for patients with advanced stage tumours.