Imaging of intrahepatic and hilar cholangiocarcinoma

Imaging features and management of focal liver lesions

Notably, the number of incidentally detected focal liver lesions (FLLs) has increased dramatically in recent years due to the increased use of radiological imaging. The diagnosis of FLLs can be made through a well-documented medical history, physical examination, laboratory tests, and appropriate imaging methods. Although benign FLLs are more common than malignant ones in adults, even in patients with primary malignancy, accurate diagnosis of incidental FLLs is of utmost clinical significance. In clinical practice, FLLs are frequently evaluated non-invasively using ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI). Although US is a cost-effective and widely used imaging method, its diagnostic specificity and sensitivity for FLL characterization are limited. FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI. MRI is a problem-solving method with high specificity and sensitivity, commonly used for the evaluation of FLLs that cannot be characterized by US or CT. Recent technical advancements in MRI, along with the use of hepatobiliary-specific MRI contrast agents, have significantly improved the success of FLL characterization and reduced unnecessary biopsies. The American College of Radiology (ACR) appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients. ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommendations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios. The American College of Gastroenterology (ACG) Clinical Guideline offers evidence-based recommendations for both the diagnosis and management of FLL. American Association for the Study of Liver Diseases (AASLD) Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma. In this article, FLLs are reviewed with a comprehensive analysis of ACR Appropriateness Criteria, ACG Clinical Guideline, AASLD Practice Guidance, and current medical literature from peer-reviewed journals. The article includes a discussion of imaging methods used for the assessment of FLL, current recommended imaging techniques, innovations in liver imaging, contrast agents, imaging features of common nonmetastatic benign and malignant FLL, as well as current management recommendations.

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Machine learning for differentiating between pancreatobiliary-type and intestinal-type periampullary carcinomas based on CT imaging and clinical findings

PURPOSE

To develop a diagnostic model for distinguishing pancreatobiliary-type and intestinal-type periampullary adenocarcinomas using preoperative contrast-enhanced computed tomography (CT) findings combined with clinical characteristics.

METHODS

This retrospective study included 140 patients with periampullary adenocarcinoma who underwent preoperative enhanced CT, including pancreaticobiliary (N = 100) and intestinal (N = 40) types. They were randomly assigned to the training or internal validation set in an 8:2 ratio. Additionally, an independent external cohort of 28 patients was enrolled. Various CT features of the periampullary region were evaluated and data from clinical and laboratory tests were collected. Five machine learning classifiers were developed to identify the histologic type of periampullary adenocarcinoma, including logistic regression, random forest, multi-layer perceptron, light gradient boosting, and eXtreme gradient boosting (XGBoost).

RESULTS

All machine learning classifiers except multi-layer perceptron used achieved good performance in distinguishing pancreatobiliary-type and intestinal-type adenocarcinomas, with the area under the curve (AUC) ranging from 0.75 to 0.98. The AUC values of the XGBoost classifier in the training set, internal validation set and external validation set are 0.98, 0.89 and 0.84 respectively. The enhancement degree of tumor, the growth pattern of tumor, and carbohydrate antigen 19-9 were the most important factors in the model.

CONCLUSION

Machine learning models combining CT with clinical features can serve as a noninvasive tool to differentiate the histological subtypes of periampullary adenocarcinoma, in particular using the XGBoost classifier.

Locoregional Approaches in Cholangiocarcinoma Treatment

Cholangiocarcinoma (CCA) is a rare hepatic malignant tumor with poor prognosis due to late detection and anatomic factors limiting the applicability of surgical resection. Without surgical resection, palliation is the most common approach. In non-surgical cases contained within the liver, locoregional therapies provide the best chance for increased survival and disease control. The most common methods, transarterial chemoembolization and transarterial radioembolization, target tumors by embolizing their blood supply and limiting the tumor's ability to metabolize. Other treatments induce direct damage via thermal ablation to tumor tissue to mediate their anti-tumor efficacy. Recent studies have begun to explore roles for these therapies outside their previous role of palliation. This review will outline the mechanisms of each of these treatments, along with their effects on overall survival, while comparing these to non-locoregional therapies.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

Imaging of Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is the second most common primary hepatic malignancy and is a heterogeneous tumor of biliary epithelium. We discuss the risk factors, anatomic classification of cholangiocarcinoma (CC) as well as the different morphologic subtypes of CC. Imaging findings of CC on different modalities are described, focusing on intrahepatic CC. Recently recognized imaging features that carry prognostic significance, such as a worse prognosis in tumors that have more desmoplastic stroma, are detailed. Other benign and malignant entities that should be considered in the differential diagnosis of CC will also be discussed.

Primary biliary non-Hodgkin's lymphoma: A case report

RATIONALE

Primary biliary non-Hodgkin's lymphoma (PBNHL) is a rare disease with only 41 cases reported since 1982. The incidence of PBNHL in patients with malignant cholangiocarcinoma was 0.6%, and PBNHL accounted for 0.4% of extranodal non-Hodgkin's lymphoma, and only 0.016% of all non-Hodgkin's lymphoma cases.

PATIENT CONCERNS

We present a rare case of PBNHL in a 59-year-old female who had jaundice for 3 days with weight loss and Epstein-Barr virus infection. Initial computed tomography and magnetic resonance imaging showed diffuse thickening wall of bile ducts with corresponding lumen stenosis, blurred fat space around the portal vein, lymphadenopathy, and a normal spleen. These manifestations and images were similar to hilar cholangiocarcinoma. So, the diagnosis of hilar cholangiocarcinoma was initially considered.

DIAGNOSES

Postoperative pathology confirmed the final diagnosis was PBNHL.

INTERVENTIONS

The patient and her family requested to clarify the histologic diagnosis by laparotomy biopsy. Because the biopsy result could not be defined during operation, then right hemihepatectomy and choledochojejunostomy were performed. She did not receive any antitumor treatment.

OUTCOMES

One month after the patient's first examination, both computed tomography and magnetic resonance images showed diminished stenosis of common bile duct and left hepatic duct, but a new mass in segment IV of liver was observed. Unfortunately, the patient died due to disease progression.

LESSONS

This case reminds us that although PBNHL is rare, making accurate diagnosis difficult preoperatively, PBNHL should be considered when encountering a case with Epstein-Barr virus infection and those typical imaging findings.

The role of quantitative diffusion-weighted imaging in characterization of hypovascular liver lesions: A prospective comparison of intravoxel incoherent motion derived parameters and apparent diffusion coefficient

BACKGROUND

The utility of intravoxel incoherent motion (IVIM) related parameters in differentiation of hypovascular liver lesions is still unknown.

PURPOSE

The purpose of this study was to evaluate the value of IVIM related parameters in comparison to apparent diffusion coefficient (ADC) for differentiation among intrahepatic mass-forming cholangiocarcinoma (IMC), and hypovascular liver metastases (HLM).

METHODS

Seventy-four prospectively enrolled patients (21 IMC, and 53 HLM) underwent 1.5T magnetic resonance examination with IVIM diffusion-weighted imaging using seven b values (0-800 s/mm2). Two independent readers performed quantitative analysis of IVIM-related parameters and ADC. Interobserver reliability was tested using a intraclass correlation coefficient. ADC, true diffusion coefficient (D), perfusion-related diffusion coefficient (D*), and perfusion fraction (ƒ) were compared among the lesions using Kruskal-Wallis H test. The diagnostic accuracy of each parameter was assessed by receiver operating characteristic (ROC) curve analysis.

RESULTS

The interobserver agreement was good for ADC (0.802), and excellent for D, D*, and ƒ (0.911, 0.927, and 0.942, respectively). ADC, and D values were significantly different among IMC and HLM (both p < 0.05), while there was no significant difference among these lesions for ƒ and D* (p = 0.101, and p = 0.612, respectively). ROC analysis showed higher diagnostic performance of D in comparison to ADC (AUC = 0.879 vs 0.821).

CONCLUSION

IVIM-derived parameters in particular D, in addition to ADC, could help in differentiation between most common hypovascular malignant liver lesions, intrahepatic mass-forming cholangiocarcinoma and hypovascular liver metastases.

Italian Clinical Practice Guidelines on Cholangiocarcinoma - Part I: Classification, diagnosis and staging

Cholangiocarcinoma (CCA) is the second most common primary liver cancer, characterized by a poor prognosis and resistance to chemotherapeutics. The progressive increase in CCA incidence and mortality registered worldwide in the last two decades and the need to clarify various aspects of clinical management have prompted the Italian Association for the Study of the Liver (AISF) to commission the drafting of dedicated guidelines in collaboration with a group of Italian scientific societies. These guidelines have been formulated in accordance with the Italian National Institute of Health indications and developed by following the GRADE method and related advancements.

Radiologic Evaluation and Structured Reporting Form for Extrahepatic Bile Duct Cancer: 2019 Consensus Recommendations from the Korean Society of Abdominal Radiology

Radiologic imaging is important for evaluating extrahepatic bile duct (EHD) cancers; it is used for staging tumors and evaluating the suitability of surgical resection, as surgery may be contraindicated in some cases regardless of tumor stage. However, the published general recommendations for EHD cancer and recommendations guided by the perspectives of radiologists are limited. The Korean Society of Abdominal Radiology (KSAR) study group for EHD cancer developed key questions and corresponding recommendations for the radiologic evaluation of EHD cancer and organized them into 4 sections: nomenclature and definition, imaging technique, cancer evaluation, and tumor response. A structured reporting form was also developed to allow the progressive accumulation of standardized data, which will facilitate multicenter studies and contribute more evidence for the development of recommendations.

Cholangiocarcinoma

Cholangiocarcinoma is a rare malignancy and accounts for 2% of all malignancies. Incidence is on the increase in the Western world. Cholangiocarcinoma arises from the malignant growth of the epithelial lining of the bile ducts and can be found all along the biliary tree. It can be classified into subtypes based on location: intrahepatic (arising from the intrahepatic biliary tract in the hepatic parenchyma), perihilar (at the hilum of the liver involving the biliary confluence) and distal (extrahepatic, often in the head of the pancreas). Margin status and locoregional lymph node metastases are the most important determinants of postsurgical outcomes.

Intrahepatic mass-forming cholangiocarcinoma and solitary hypovascular liver metastases: is the differential diagnosis using diffusion-weighted MRI possible?

Background Intrahepatic mass-forming cholangiocellular carcinoma (IMC) is the second most common primary liver tumor. The differentiation between IMC and solitary hypovascular liver metastases (SHLM) represents a diagnostic challenge due to many overlapping magnetic resonance imaging (MRI) features. Purpose To determine the value of diffusion-weighted imaging (DWI) in addition to conventional MRI for the distinction between intrahepatic mass-forming cholangiocarcinoma and solitary hypovascular liver metastases. Material and Methods Fifty-three patients with pathologically proven IMC (n = 31) and SHLM (n = 22) who had undergone MRI and DWI before surgery or percutaneous biopsy were enrolled in this study. The following MRI features were analyzed: the size and shape of the lesion, presence of capsular retraction and segmental biliary dilatation, T2-weighted (T2W) signal intensity, the presence of target sign on DWI and enhancement pattern. Apparent diffusion coefficient (ADC) values were calculated for each lesion ( b = 800 s/mm²). Univariate and multivariate logistic regression analyses were used to identify significant differentiating features between IMCs and SHLMs. Results Univariate analysis revealed that following parameters favor diagnosis of IMCs over SHLMs: lobulating shape, heterogeneous T2W signal intensity, capsular retraction, segmental biliary dilatation, target sign on DWI and rim-like enhancement on arterial phase followed by progressive enhancement in delayed phases. ADC values measured in the periphery of the lesion were significantly lower in IMCs in comparison to SHLMs. Multivariate analysis revealed that target sign on DWI was the most significant predictor of IMCs. Conclusion Qualitative DWI analysis with target sign significantly improves diagnostic accuracy for differentiation among IMC and SHLM lesions.

Intrahepatic and hilar mass-forming cholangiocarcinoma: Qualitative and quantitative evaluation with diffusion-weighted MR imaging

OBJECTIVE

To qualitatively and quantitatively analyze the presentation of intrahepatic and hilar mass-forming cholangiocarcinoma with diffusion-weighted magnetic resonance imaging (DW-MRI).

MATERIALS AND METHODS

Twenty-eight patients with histopathologically proven mass-forming cholangiocarcinoma (hilar, n=17; intrahepatic, n=11) underwent hepatic DW-MRI at 1.5-T using free-breathing acquisition and three b-values (0,400,800s/mm(2)). Cholangiocarcinomas were evaluated qualitatively using visual analysis of DW-MR images and quantitatively with conventional ADC and normalized ADC measurements using liver and spleen as reference organs.

RESULTS

All cholangiocarcinomas (28/28; 100%) were visible on DW-MR images. DW-MRI yielded best conspicuity of cholangiocarcinomas than the other MRI sequences (P<0.001). Seven cholangiocarcinomas (7/11; 64%) showed hypointense central area on DW-MR images. Conventional ADC value of cholangiocarcinomas (1.042×10(-3)mm(2)/s±0.221×10(-3)mm(2)/s; range: 0.616×10(-3)mm(2)/s to 2.050×10(-3)mm(2)/s) was significantly lower than that of apparently normal hepatic parenchyma (1.362×10(-3)mm(2)/s±0.187×10(-3)mm(2)/s) (P<0.0001), although substantial overlap was found. No significant differences in ADC and normalized ADC values were found between intrahepatic and hilar cholangiocarcinomas. The use of normalized ADC using the liver as reference organ resulted in the most restricted distribution of ADC values of cholangiocarcinomas (variation coefficient=16.6%).

CONCLUSION

There is a trend towards a common appearance of intrahepatic and hilar mass-forming cholangiocarcinomas on DW-MRI but variations may be observed. Familiarity with these variations may improve the diagnosis of mass-forming cholangiocarcinoma.

Noninvasive Imaging of the Biliary Tree for the Interventional Radiologist

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

CA 19-9 in combination with abdominal CT scan for the diagnosis of mass-forming intrahepatic cholangiocarcinoma

Aim

Cholangiocarcinoma (CCA) is a common form of cancer in Thailand. The diagnosis of CCA by pathology is widely accepted. Unfortunately, tissue diagnosis of mass-forming intrahepatic cholangiocarcinoma is difficult to perform due to the risk of the procedure and accessibility. The aim of this study is to assess the diagnostic utility of CA19-9 in combination with CT scan for the diagnosis of mass-forming cholangiocarcinoma.

Materials & methods

The medical records of patients with a diagnosis of CCA and hepatocellular carcinoma (HCC) during January 2005-December 2009 were reviewed. Only cases with pathology and CT scan reports from Maharaj Nakorn Chiang Mai Hospital were included. Demographic data, clinical manifestations and laboratory results, including CA19-9 and CT scans of the liver, were carefully examined in order to establish their diagnostic utility in mass-forming CCA without a pathological diagnosis.

Results

A total of 79 CCA patients and 66 HCC patients were included in CA19-9 cut-off level analyses. A total of 31 CCA patients and 44 HCC patients were included in the CT scan evaluation and scored according to the Chiang Mai CT score for CCA. The specificity of a CA19-9 value of 500 U/ml for the diagnosis of CCA was 95.5% with a sensitivity of 50.6%, positive predictive value of 91.8% and likelihood ratio of positive (LR+) of 11.24. A CT score greater than 2 demonstrates a positive predictive value of more than 90% in diagnosis of CCA. The CA19-9 level of 140 U/ml in combination with a CT score of 2 demonstrated LR+ as high as 57.09. A CA19-9 level of 280 U/ml in combination with a CT score of 1 demonstrated LR+ of 58.4.

Conclusion

A CA19-9 level combined with the Chiang Mai CT score for CCA are good diagnostic tools for the diagnosis of mass-forming cholangiocarcinoma with high specificity, high positive predictive value and high likelihood ratio of positive.

Diagnosis and management of intrahepatic cholangiocarcinoma: a comprehensive update for the radiologist

There is increasing focus on intrahepatic cholangiocarcinoma (IHCC) due to its rising incidence worldwide and relatively poor prognosis, with the revised TNM classification (2009) introducing a separate staging system for IHCC for the first time. In this article, we comprehensively review the current role of the radiologist in the diagnosis and management of patients with IHCC.

Selective internal radiotherapy (SIRT) versus transarterial chemoembolization (TACE) for the treatment of intrahepatic cholangiocellular carcinoma (CCC): study protocol for a randomized controlled trial

Background

Cholangiocellular carcinoma is the second most common primary liver cancer after hepatocellular carcinoma. Over the last 30 years, the incidence of intrahepatic cholangiocellular carcinoma has risen continuously worldwide. Meanwhile, the intrahepatic cholangiocellular carcinoma has become more common than the extrahepatic growth type and currently accounts for 10-15% of all primary hepatic malignancies. Intrahepatic cholangiocellular carcinoma is typically diagnosed in advanced stages due to late clinical symptoms and an absence of classic risk factors. A late diagnosis precludes curative surgical resection. There is evidence that transarterial chemoembolization leads to better local tumor control and prolongs survival compared to systemic chemotherapy. New data indicates that selective internal radiotherapy, also referred to as radioembolization, provides promising results for treating intrahepatic cholangiocellular carcinoma.

Methods/Design

This pilot study is a randomized, controlled, single center, phase II trial. Twenty-four patients with intrahepatic cholangiocellular carcinoma will be randomized in a 1:1 ratio to receive either chemoembolization or radioembolization. Randomization will be stratified according to tumor load. Progression-free survival is the primary endpoint; overall survival and time to progression are secondary endpoints. To evaluate treatment success, patients will receive contrast enhanced magnetic resonance imaging every 3 months.

Discussion

Currently, chemoembolization is routinely performed in many centers instead of systemic chemotherapy for treating intrahepatic cholangiocellular carcinoma confined to the liver. Recently, radioembolization has been increasingly applied to cholangiocellular carcinoma as second line therapy after TACE failure or even as an alternative first line therapy. Nonetheless, no randomized studies have compared radioembolization and chemoembolization. Considering all this background information, we recognized a strong need for a randomized controlled trial (RCT) to compare the two treatments. Therefore, the present protocol describes the design of a RCT that compares SIRT and TACE as the first line therapy for inoperable CCC confined to the liver.

Trial registration

ClinicalTrials.gov, Identifier: NCT01798147, registered 16^th of February 2013.

Hilar cholangiocarcinoma: diagnosis, treatment options, and management

Hilar cholangiocarcinoma (HC) is a rare disease with a poor prognosis which typically presents in the 6(th) decade of life. Of the 3,000 cases seen annually in the United States, less than one half of these tumors are resectable. A variety of risk factors have been associated with HC, most notably primary sclerosing cholangitis (PSC), biliary stone disease and parasitic liver disease. Patients typically present with abdominal pain, pruritis, weight loss, and jaundice. Computed topography (CT), magnetic resonance imaging (MRI), and ultrasound (US) are used to characterize biliary lesions. Endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC) assess local ductal extent of the tumor while allowing for therapeutic biliary drainage. MRCP has demonstrated similar efficacies to PTC and ERCP in identifying anatomic extension of tumors with less complications. Treatment consists of surgery, radiation, chemotherapy and photodynamic therapy. Biliary drainage of the future liver remnant should be performed to decrease bilirubin levels thereby facilitating future liver hypertrophy. Standard therapy consists of surgical margin-negative (R0) resection with extrahepatic bile duct resection, hepatectomy and en bloc lymphadenectomy. Local resection should not be undertaken. Lymph node invasion, tumor grade and negative margins are important prognostic indicators. In instances where curative resection is not possible, liver transplantation has demonstrated acceptable outcomes in highly selected patients. Despite the limited data, chemotherapy is indicated for patients with unresectable tumors and adequate functional status. Five-year survival after surgical resection of HC ranges from 10% to 40% however, recurrence can be as high as 50-70% even after R0 resection. Due to the complexity of this disease, a multi-disciplinary approach with multimodal treatment is recommended for this complex disease.

Imaging of malignancies of the biliary tract- an update

Malignancies of the biliary tract include cholangiocarcinoma, gallbladder cancers and carcinoma of the ampulla of Vater. Biliary tract adenocarcinomas are the second most common primary hepatobiliary cancer. Due to their slow growing nature, non-specific and late symptomatology, these malignancies are often diagnosed in advanced stages with poor prognosis. Apart from incidental discovery of gall bladder carcinoma upon cholecystectomy, early stage biliary tract cancers are now detected with computed tomography (CT) and magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP). Accurate characterization and staging of these indolent cancers will determine outcome as majority of the patients’ are inoperable at the time of presentation. Ultrasound is useful for initial evaluation of the biliary tract and gallbladder masses and in determining the next suitable modality for further evaluation. Multimodality imaging plays an integral role in the management of the biliary tract malignancies. The imaging techniques most useful are MRI with MRCP, endoscopic retrograde cholangiopancreatography (ERCP), endoscopic ultrasound (EUS) and positron emission tomography (PET). In this review we will discuss epidemiology and the role of imaging in detection, characterization and management of the biliary tract malignancies under the three broad categories of cholangiocarcinomas (intra- and extrahepatic), gallbladder cancers and ampullary carcinomas.

MR imaging of the biliary system

Although ultrasound, computed tomography, and cholescintigraphy play essential roles in the evaluation of suspected biliary abnormalities, magnetic resonance (MR) imaging and MR cholangiopancreatography can be used to evaluate inconclusive findings and provide a comprehensive noninvasive assessment of the biliary tract and gallbladder. This article reviews standard MR and MR cholangiopancreatography techniques, clinical applications, and pitfalls. Normal biliary anatomy and variants are discussed, particularly as they pertain to preoperative planning. A spectrum of benign and malignant biliary processes is reviewed, emphasizing MR findings that aid in characterization.

Unusual images of mass-forming intrahepatic cholangiocarcinoma

We experienced a case of mass-forming intrahepatic cholangiocarcinoma which could not been diagnosed accurately without pathologic findings. A 78-year-old Japanese woman with no particular symptoms was admitted for changes in liver function tests. Ultrasonography revealed a solid liver tumor. When there are no typical imaging features, no pathognomonic clinical findings and no obvious risk factors for any specific hepatic tumor, it may be difficult to make an accurate diagnosis before surgical resection. The lesion was resected on the basis of a high degree of suspicion for malignancy and submitted for pathologic evaluation. Microscopically, the neoplasm was a moderately differentiated adenocarcinoma with abundant fibrous stroma, consistent with a mass-forming cholangiocarcinoma. This case exemplifies the importance of considering the various tumorous and non-tumorous diseases in the differential diagnosis of a liver mass with atypical features, especially when malignancy cannot be excluded.

The Preoperative Assessment of Hepatic Tumours: Evaluation of UK Regional Multidisciplinary Team Performance

Introduction. In the UK, patients where liver resection is contemplated are discussed at hepatobiliary multidisciplinary team (MDT) meetings. The aim was to assess MDT performance by identification of patients where radiological and pathological diagnoses differed. Materials and Methods. A retrospective review of a prospectively maintained database of all cases undergoing liver resection from March 2006 to January 2012 was performed. The presumed diagnosis as a result of radiological investigation and MDT discussion is recorded at the time of surgery. Imaging was reviewed by specialist gastrointestinal radiologists, and resultswereagreedonby consensus. Results. Four hundred and thirty-eight patients were studied. There was a significant increase in the use of preoperative imaging modalities (P ≤ 0.01) but no change in the rate of discrepant diagnosis over time. Forty-two individuals were identified whose final histological diagnosis was different to that following MDT discussion (9.6%). These included 30% of patients diagnosed preoperatively with hepatocellular carcinoma and 25% with cholangiocarcinoma of a major duct. Discussion. MDT assessment of patients preoperatively is accurate in terms of diagnosis. The highest rate of discrepancies occurred in patients with focal lesions without chronic liver disease or primary cancer, where hepatocellular carcinoma was overdiagnosed and peripheral cholangiocarcinoma underdiagnosed, where particular care should be taken. Additional care should be taken in these groups and preoperative multimodality imaging considered.

The T1W hyperintense signal on the surface of distal segment of bile duct tumor thrombi and its significance

RATIONALE AND OBJECTIVES

To evaluate the magnetic resonance (MR) findings of bile duct tumor thrombi (BDTT) and intraductal growing-type cholangiocarcinoma (IDG-type CC), especially focusing on the distal segment of intrabiliary tumors.

MATERIALS AND METHODS

Twenty-nine cases of hepatocellular carcinoma with BDTT and 17 cases of IDG-type CC were available for retrospective review. The following MR findings were evaluated: presence of necrosis and T1-weighted (T1W) hyperintense signal on the surface of the distal segment of intrabiliary tumors, bile duct wall thickening adjacent to the tumor, dilation of bile duct of the tumor-bearing segment, location and maximum diameter of intraductal mass, and presence of a hepatic parenchymal mass.

RESULTS

There was significant difference in T1W hyperintense signal on the surface of the distal segment of intrabiliary tumors between BDTT and IDG-type CC (P < .05). The T1W hyperintense signal detected in BDTT was identified as bile layering (9/25) or hemobilia (16/25) pathologically. For the diagnosis of BDTT, the sensitivity and specificity of T1W hyperintense signal was 86.2% and 100%, respectively. There was significant difference in necrosis at the distal end of intrabiliary tumors and presence of hepatic parenchymal mass between BDTT and IDG-type CC (P < .05). However, no statistical significance was found in bile duct dilation, the absence of wall thickening, the location of intraductal mass, or the maximum diameter of intrabiliary mass between the two groups (P > .05).

CONCLUSIONS

The T1W hyperintense signal on the distal segment of intrabiliary mass was because of concentrated bile deposits or hemobilia. The sign of T1W hyper signal on the distal segment is valuable to differentiate BDTT and IDG-type CC.

Current management of cholangiocarcinoma

Cholangiocarcinoma is the second most common primary hepatobiliary malignancy after hepatocellular carcinoma and remains among the most difficult management problems faced by surgeons. Curative surgery is achieved in only 25% to 30% of patients. Local tumor extent, such as portal vein invasion and hepatic lobar atrophy, does not preclude resection. Long-term survival has been seen only in patients who underwent extensive liver resections, suggesting that bile-duct excision alone is less effective. The majority of patients have unresectable disease, with 20% to 30% incidence of distant metastasis at presentation. Unresectable patients should be referred for nonsurgical biliary decompression, and in potential curative resection candidates the use of biliary stents should be reduced. Liver transplantation provides the option of wide resection margins, expanding the indication of surgical intervention for selected patients who otherwise are not surgical candidates due to lack of functional hepatic reserve.

Solitary hepatic granuloma preoperatively diagnosed as intrahepatic cholangiocellular carcinoma: report of a case

We herein report the case of a 67-year-old female with a solitary hepatic granuloma preoperatively diagnosed as a mass-forming type of intrahepatic cholangiocellular carcinoma. Magnetic resonance imaging using gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid as a contrast medium is expected to be useful for making a differential diagnosis between hepatic granuloma and other hypovascular liver tumors, such as the mass-forming type of intrahepatic cholangiocellular carcinoma and metastatic liver tumors.

MRCP and 3D LAVA imaging of extrahepatic cholangiocarcinoma at 3 T MRI

Extrahepatic cholangiocarcinoma (CCA) is a primary bile duct malignant tumour with poor prognosis. Familiarity with their varied imaging characteristics can be helpful in developing a correct diagnosis and in optimal treatment planning, and thus contribute to a better prognosis. The purpose of this article is to illustrate the typical appearances of extrahepatic CCA on magnetic resonance cholangiopancreatography (MRCP) and three-dimensional (3D) LAVA (liver acquisition with volume acceleration) sequences at 3 T magnetic resonance imaging (MRI), and to discuss the superiority of the two techniques in the diagnosis of CCA.

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.

Tumors of the liver and intrahepatic bile ducts: radiologic-pathologic correlation

Primary tumors of the liver can be classified pathologically based on their cell of origin into epithelial tumors, arising from hepatocytes or biliary epithelium, and nonepithelial tumors, including mesenchymal tumors and lymphoma. Characteristic findings on MR imaging can be seen in many cases. This article reviews the MR imaging appearance of these tumors with pathologic correlation.

Biliary, pancreatic, and hepatic imaging for the general surgeon

Technologic advancements have allowed imaging modalities to become more useful in the diagnosis of hepatobiliary and pancreatic disorders. Computed tomography scanners now use multidetector row technology with contrast-delayed imaging for quicker and more accurate imaging. Magnetic resonance imaging with cholangiopancreatography can more clearly delineate liver lesions and the biliary and pancreatic ducts, and can diagnose pathologic conditions early in their course. Newer technologies, such as single-operator cholangioscopy and endoscopic ultrasonography, have sometimes shown superiority to traditional modalities. This article addresses the literature regarding available imaging techniques in the diagnosis and treatment of common surgical hepatobiliary and pancreatic diseases.

Synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type C liver cirrhosis

As a result of having undergone computed tomography (CT), a 75-year-old woman with type-C liver cirrhosiswas shown to have two tumors on the ventral and dorsal sides of subsegment 3 (S3). The tumor on the ventral side was diagnosed as a classic hepatocellular carcinoma (HCC), while that on the dorsal side was considered atypical for a HCC. Although the indocyanine green (ICG) findings indicated poor hepatic reserve, the prothrombin time (PT) was relatively good. An operation was performed in February 2007; however, this resulted in exploratory laparotomy. Dynamic CT performed 12 mo after the operation revealed that the tumor on the dorsal side of S3 had apparently increased. The marginal portion of the tumor was shown to be in the early and parenchymal phases, while the internal portion was found to have grown only slightly in the delayed phase. We diagnosed this tumor as a cholangiocellular carcinoma (CCC). S3 subsegmentectomy was performed in April 2008. The tumor on the ventral side was pathologically diagnosed as a moderately differentiated HCC, and that on the dorsal side was diagnosed as a CCC. We can therefore report a rare case of synchronous development of HCC and CCC in the same subsegment of the liver in a patient with type-C liver cirrhosis. We also add a literature review for all the reported cases published in Japan and around the world, and summarize the features of double cancer exhibiting both HCC and CCC.

Advances in diagnosis, treatment and palliation of cholangiocarcinoma: 1990-2009

Several advances in diagnosis, treatment and palliation of cholangiocarcinoma (CC) have occurred in the last decades. A multidisciplinary approach to this disease is therefore recommended. CC is a relatively rare tumor and the main risk factors are: chronic inflammation, genetic predisposition and congenital abnormalities of the biliary tree. While the incidence of intra-hepatic CC is increasing, the incidence of extra-hepatic CC is trending down. The only curative treatment for CC is surgical resection with negative margins. Liver transplantation has been proposed only for selected patients with hilar CC that cannot be resected who have no metastatic disease after a period of neoadjuvant chemo-radiation therapy. Magnetic resonance imaging/magnetic resonance cholangiopancreatography, positron emission tomography scan, endoscopic ultrasound and computed tomography scans are the most frequently used modalities for diagnosis and tumor staging. Adjuvant therapy, palliative chemotherapy and radiotherapy have been relatively ineffective for inoperable CC. For most of these patients biliary stenting provides effective palliation. Photodynamic therapy is an emerging palliative treatment that seems to provide pain relief, improve biliary patency and increase survival. The clinical utility of other emerging therapies such as transarterial chemoembolization, hepatic arterial chemoinfusion and high intensity intraductal ultrasound needs further study.

Intrahepatic cholangiocarcinoma and hepatocellular carcinoma: differential diagnosis with contrast-enhanced ultrasound

OBJECTIVE

We assessed the usefulness of contrast-enhanced ultrasound (CEUS) in the differentiation of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

METHODS

The CEUS enhancement patterns of 50 ICCs were retrospectively analysed and compared with 50 HCCs. Two readers independently reviewed the baseline ultrasound (BUS) and CEUS images and the diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis. Time-intensity curves (TIC) were plotted for quantification analysis.

RESULTS

In the arterial phase, peripheral rim-like hyperenhancement, heterogeneous hyperenhancement, homogeneous hyperenhancement and heterogeneous hypoenhancement were found in 25, 10, 3 and 12 of the ICCs versus 2, 29, 19 and 0 of the HCCs (P < 0.001), respectively. The diagnostic performance of both readers in terms of the area under the ROC curve (0.745 vs. 0.933 for reader 1, and 0.803 vs. 0.911 for reader 2), sensitivity (28% vs. 90%, and 44% vs. 82%) and accuracy (64% vs. 90%, and 71% vs. 90%) improved significantly after CEUS (all P < 0.05). The interobserver agreement increased from kappa = 0.575 at BUS to kappa = 0.720 after CEUS. TICs demonstrated that the intensities of the peripheral and central portions of the ICCs were lower than those of HCCs (both P < 0.05).

CONCLUSION

CEUS improves the diagnostic performance significantly in the differentiation between ICC and HCC.

Enhancement pattern of hilar cholangiocarcinoma: contrast-enhanced ultrasound versus contrast-enhanced computed tomography

OBJECTIVE

To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT).

METHODS

Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated.

RESULTS

In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P=0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P=0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ultrasound, 89.5% (17/19) for CEUS, and 78.9% (15/19) for CECT (all P>0.05 between every two groups). CEUS significantly improved the lesion conspicuity in comparison with CECT. CEUS and CECT made correct diagnoses in 30 (93.8%) and 25 (78.1%) lesions prior to pathological examination (P=0.125).

CONCLUSION

The enhancement pattern of hilar cholangiocarcinoma on CEUS was similar with that on CECT in arterial phase, whereas in portal phase hilar cholangiocarcinoma shows hypoenhancement more likely on CEUS. CEUS and CECT lead to similar results in evaluating portal vein infiltration and diagnosis of this entity.

Comparative diagnostic evaluation with MR cholangiopancreatography, ultrasonography and CT in patients with pancreatobiliary disease

PURPOSE

The aim of this study was to directly compare the results of magnetic resonance cholangiopancreatography (MRCP) with those of ultrasonography (US) and multislice computed tomography (MSCT) in the diagnosis of pancreaticobiliary diseases.

MATERIALS AND METHODS

A total of 70 patients (41 men, 29 women) aged 22-89 years were studied either before (n=59) or after cholecystectomy (n=11) for biliary lithiasis. Clinical signs and symptoms were jaundice (n=15), abdominal pain (n=37) and proven biliary lithiasis (n=18). MRCP was performed in all patients, whereas abdominal US was performed in 55 (group 1) and MSCT in 37 (group 2) patients. A regional evaluation of the main structures of the pancreaticobiliary system was performed: gallbladder and cystic duct, intra- and extrahepatic bile ducts and main pancreatic duct. Histology (n=27), biopsy (n=5), endoscopic retrograde cholangiopancreatography (ERCP) (n=28) and/or clinical-imaging follow-up (n=10) were considered standards of reference. In particular, patients were classified as showing benign (n=47) or malignant (n=12) lesions or normal biliary anatomy (n=11).

RESULTS

In group 1, the results of MRCP and US were concordant in the majority (92%) of cases; however, statistically significant discordance (p<0.01) was found in the evaluation of the extrahepatic ducts, with nine cases (16%) of middle-distal common bile duct stones being detected on MRCP only. In group 2, the results of MRCP and MSCT were also concordant in most cases (87%). However, findings were significantly discordant when the intra- and extrahepatic ducts were analysed, with seven (19%) and six (16%) cases, respectively, of lithiasis being detected on MRCP only (p<0.01 for both).

CONCLUSIONS

The results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.

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

PURPOSE

The purpose of this study was to characterize the differences in CT enhancement pattern among the morphologic subtypes of cholangiocarcinomas.

MATERIALS AND METHODS

Unenhanced, hepatic arterial (HAP), and portal venous phase (PVP) CT images of 84 patients with pathologically proven cholangiocarcinoma were retrospectively reviewed. Tumors were of the following types: 27 mass-forming, 39 periductal-infiltrating, and 18 intraductal. The CT attenuation values of tumors were measured at each phase. The tumor enhancement ratio (ER) on HAP and PVP was calculated.

RESULTS

Each cholangiocarcinoma subtype produced characteristic enhancement relative to liver on HAP and PVP images: mass-forming tumors demonstrated hyperenhancing periphery and hyopenhancing centers; periductal-infiltrating tumors, hyperenhancing; and intraductal tumors, hypoenhancing. The ER of the tumor types was significantly different (P<.001, HAP, PVP): periductal-infiltrating tumors showed the highest ER (2.5; 3.8); the centers of mass-forming tumors, lowest (1.5; 2.2); the peripheries of mass-forming tumors, high (2.1; 3.0); intraductal tumors, low (1.9; 2.6).

CONCLUSION

Cholangiocarcinoma subtypes tended to exhibit distinct enhancement characteristics. Knowledge of these enhancement patterns may aid diagnosis and surgical planning.

Hilar cholangiocarcinoma: MRI/MRCP in staging and treatment planning

The role of MR imaging in hilar cholangiocarcinoma is to confirm/reach a diagnosis and to assess resectability. Hilar cholangiocarcinoma shows the same signal intensity pattern of peripheral tumors both on T1- and T2-weighted images. On magnetic resonance cholangiopancreatography (MRCP) images, hilar cholangiocarcinoma appears as a moderately irregular thickening of the bile duct wall (5 mm) with symmetric upstream dilation of the intrahepatic bile ducts. The aim of preoperative investigation in Klatskin tumors typically requires the evaluation of the level of biliary obstruction, the intrahepatic tumor spread, and the vascular involvement; it also needs to show any atrophy-hypertrophy complex. Because of its intrinsic high tissue contrast and multiplanar capability, MR imaging and MRCP are able to detect and preoperatively assess patients with cholangiocarcinoma, investigating all involved structures such as bile ducts, vessels and hepatic parenchyma. The main reason for surgical/imaging discrepancy is represented by the microscopic diffusion along the mucosa and in the perineural space.

MR Imaging of hepatocellular carcinoma in the cirrhotic liver: challenges and controversies

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the next 2 decades, largely due to hepatitis C infection and secondary cirrhosis. HCC is being detected at an earlier stage owing to the implementation of screening programs. Biopsy is no longer required prior to treatment, and diagnosis of HCC is heavily dependent on imaging characteristics. The most recent recommendations by the American Association for the Study of Liver Diseases (AASLD) state that a diagnosis of HCC can be made if a mass larger than 2 cm shows typical features of HCC (hypervascularity in the arterial phase and washout in the venous phase) at contrast material-enhanced computed tomography or magnetic resonance (MR) imaging or if a mass measuring 1-2 cm shows these features at both modalities. There is an ever-increasing demand on radiologists to detect smaller tumors, when curative therapies are most effective. However, the major difficulty in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. The authors present a review of the MR imaging and pathologic features of regenerative nodules and dysplastic nodules and focus on HCC in the cirrhotic liver, with particular reference to small tumors and lesions that may mimic HCC. The authors also review the sensitivity of MR imaging for the detection of these tumors and discuss the staging of HCC and the treatment options in the context of the guidelines of the AASLD and the imaging criteria required by the United Network for Organ Sharing for transplantation. MR findings following ablation and chemoembolization are also reviewed.

[Diagnostic imaging of liver tumours. Current status]

Nowadays, contrast enhanced ultrasound (CEUS) is an imaging technique equivalent to multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection and characterization of focal liver lesions. These methods have comparable sensitivity and specificity in differentiating a liver lesion as "benign" or "malignant". For benign lesions, CEUS is the recommended method of the choice. In unclear cases, or if CEUS is not available, MRI or CT are the methods of the second choice. If a benign tumor remains unclear, then a needle biopsy is recommended. In the case of a malignant tumor, it is necessary to use a second imaging technique besides CEUS. In addition to the detection and characterization of a liver tumor, CT and MRI provide information on the extrahepatic spread of a tumor, particularly into the lung or retroperitoneum. The rapid development of surgical and interventional approaches requires accurate information on the character and number of malignant liver lesions. Therefore, the combined use of CEUS and MDCT or MRI currently represents the most modern and optimal standard of imaging. The standardization of CT and MRI protocols has increased the general diagnostic level of these images. Adequate training and a certificate for the use of CEUS is recommended in order to maintain the high diagnostic level of this method (EFSUMB guide lines). An optimal interdisciplinary imaging strategy for focal liver lesions minimises unnecessary invasive or potentially harmful imaging and reduces health costs.

Is preoperative histological diagnosis necessary before referral to major surgery for cholangiocarcinoma?

Major surgical resection is often the only curative treatment for cholangiocarcinoma. When imaging techniques fail to establish the accurate diagnosis, biopsy of the lesion is unavoidable. However, biopsy is not necessarily required for topography of the cholangiocarcinoma (intrahepatic or extrahepatic). 1) In extrahepatic cholangiocarcinoma (ECC), clinical features and radiological imaging relate to biliary obstruction. Provided that between 8% and 43% of bile duct strictures are not ECC, the lesions mimicking ECC that should be ruled out are gallbladder cancer, Mirizzi syndrome, primary sclerosing cholangitis (PSC), autoimmune pancreatitis and portal biliopathy. Systematic biopsy is usually difficult and has poor sensitivity, but a good knowledge of these mimicking ECC diseases, along with precise analysis of clinical and imaging semiology, may lead to a correct diagnosis without the need for biopsy. 2) Intrahepatic cholangiocarcinoma (ICC) developing in normal liver appears as a hypovascular tumour with fibrotic component and capsular retraction that can be confused with fibrous metastases such as breast and colorectal cancers. The lack of the primary site, a relatively large tumour size and ancillary findings such as bile duct dilatation may provide a clue to the diagnosis. If not, we advocate local resection with lymph node dissection, since ICC is the most likely diagnosis and surgery is the only curative treatment. In the event of adenocarcinoma from unknown primary, surgery is an effective treatment even if prognosis is poor.

Biliary tract neoplasms: diagnosis and staging

Most biliary tract neoplasms are malignant and have been traditionally divided into cancers of the gallbladder, the extrahepatic bile ducts, and ampulla of Vater. Although infrequent, bile duct carcinomas and cancer of the gallbladder are not rare. In the United States, an estimated 6000-7000 new cases of carcinoma of the gallbladder and 3000-4000 new cases of carcinoma of the bile ducts are diagnosed annually. Familiarity with the imaging characteristics of gallbladder and bile duct neoplasms is important to expedite the diagnosis and appropriate treatment of patients who often present with non-specific symptoms of right upper quadrant pain, jaundice, and weight loss.

Diagnostic imaging of carcinomas of the gallbladder and the bile ducts

Early diagnosis and accurate staging of carcinomas of the gallbladder and the bile ducts are helpful in improving the prognosis. Ultrasonography (US), a useful initial modality when exploring the background of jaundice or non-specific gastrointestinal complaints, sensitively reveals bile duct obstruction in particular. In unclear cases, or if US suggests a resectable biliary malignancy, computed tomography (CT), magnetic resonance imaging (MRI) with magnetic resonance cholangiography (MRC) and / or traditional cholangiography often provide additional information, and imaging-guided fine-needle biopsy or an endoscopic brush sample may verify the malignant nature of the tumor. Complementary modalities are usually needed for accurate staging, and traditional cholangiography is often performed for therapeutic purposes as well. Comparative studies of MRI with MRC and multidetector CT in biliary cancers would be welcome.

Accuracy of preoperative routine MRI for hepatic lesion detection

BACKGROUND

The outcome of liver resections depends on complete removal of all detectable foci. Our aim was to determine the value of preoperative routine magnetic resonance imaging (MRI) for complete detection of hepatic lesions.

METHODS

We compared 271 lesions seen on MRI in 182 patients to intraoperative findings (including intraoperative ultrasonography) and histology.

RESULTS

The overall rate of lesions was 7% each for segments 2 and 3, as compared to 14-17% each for segments 5, 6, 7, and 8. Twenty-three additional lesions were found intraoperatively, two thirds of them in the left lobe (mean size: 1.4 cm; mean total number of lesions in those patients: 2.2). In segments 2 and 3, the relative frequency for intraoperative diagnosis of additional lesions was 17% and 20%, respectively. On the other hand, most of the 15 MRI lesions not verified intra- or postoperatively had been described in the right hepatic lobe (maximum: segment 6).

CONCLUSION

MRI provided reliable preoperative lesion detection. Special attention should be paid to segments 2 and 3, which showed a lower total number of lesions but an elevated relative frequency of intraoperatively detected additional foci.

Preoperative assessment of resectability of hepatic hilar cholangiocarcinoma: combined CT and cholangiography with revised criteria

PURPOSE

To retrospectively assess the accuracy of combined multiphasic computed tomography (CT) and direct cholangiography for evaluation of the resectability of hilar cholangiocarcinoma, on the basis of revised criteria for unresectability, by using surgery as the reference standard.

MATERIALS AND METHODS

Institutional review board approval was obtained, and informed consent was waived. From 1998 to 2003, 55 patients (37 men, 18 women; mean age +/- standard deviation, 59 years +/- 12) with surgically proved hilar cholangiocarcinomas who underwent preoperative CT (single-detector row CT, n = 26; multi-detector row CT, n = 29) and cholangiography were included for study. The authors' revised criteria for unresectable tumor were contralateral hepatic artery invasion; main or contralateral portal vein invasion longer than 2 cm; biliary extension to the contralateral secondary confluence, farther than 2 cm from hepatic hilum; enlarged lymph nodes at the celiac, portacaval, and paraaortic area; and other ancillary findings. Tumor resectability based on these parameters was determined at imaging by two radiologists in consensus. Mann-Whitney U test and weighted kappa coefficient of agreement were used for accuracy determination.

RESULTS

For depiction of portal vein invasion (in 26 patients), CT yielded an accuracy of 85.5%. Arterial invasion was found at surgery in 19 patients, with CT providing an accuracy of 92.7%. For prediction of node involvement (15 patients, 27%), CT yielded an accuracy of 83.6%. The extent of ductal involvement could be accurately predicted in 46 patients (84%) (weighted kappa = 0.767). In 30 of 42 patients with disease classified as resectable according to revised criteria, disease was found to be resectable at surgery (71.4% positive predictive value). In 11 of 13 patients with disease classified as unresectable according to revised criteria, unresectable disease was confirmed (84.6% negative predictive value). Overall accuracy of resectability was 74.5%.

CONCLUSION

Combined interpretation of CT and direct cholangiographic images by using our revised criteria resulted in overall accuracy of 74.5% for prediction of resectability for hilar cholangiocarcinoma.

[Imaging in congenital fibrocystic diseases of the liver]

The identification of dilatations of the intrahepatic bile ducts in the absence of bile duct obstruction is rare. Imaging techniques, especially MR cholangio-pancreaticography, generally permit the distinction between fibrocystic liver diseases and polycystic liver diseases. The presence of dilated sacciform or tubular bile ducts on cholangio-pancreaticography associated with a centrally located fibrovascular bundle (central dot sign) suggests Caroli's syndrome. The presence of associated signs of liver dysmorphia including right lobe atrophy and hypertrophy of segment IV suggests associated congenital hepatic fibrosis. The findings on cholangio-pancreaticography, computerized tomography or Doppler ultrasonography correlate well with the pathogenesis of fibrocystic liver diseases, linked to an embryologic malformation of the ductal plate.

Liver masses

In summary, MR imaging is superior to other imaging modalities, including CT, for the work-up of liver masses. The current challenge is whether the superior performance of MR imaging translates into a beneficial effect on patient management, disease outcome, and health care costs. New MR sequences, phased-array surface coils, and tissue-specific MR contrast agents suggest that MR imaging may exceed further the diagnostic ability of CT.