Cross-sectional imaging of biliary tumors: current clinical status and future developments

Diagnosis of cholangiocarcinoma in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the hepatobiliary system characterized by chronic inflammation, progressive fibrosis, stricture formation and destruction of extrahepatic and intrahepatic bile ducts. Areas covered: The increased incidence of cholangiocarcinoma (CCA) in PSC has been well documented and can be explained by the continuous inflammation in the biliary tree leading to an enhanced dysplasia-carcinoma sequence. Although PSC patients may progress to liver cirrhosis; CCA most commonly occurs between the ages of 30 and 45 years when cirrhosis has not yet developed. Therefore, CCA in patients with PSC occurs earlier than in patients without PSC. Expert commentary: Despite improvement in diagnostic methods and devices, the dilemma of diagnosing CCA in patients with PSC has not been solved yet and needs further investigation.

Diagnostic accuracy of magnetic resonance, computed tomography and contrast enhanced ultrasound in radiological multimodality assessment of peribiliary liver metastases

PURPOSE

We compared diagnostic performance of Magnetic Resonance (MR), Computed Tomography (CT) and Ultrasound (US) with (CEUS) and without contrast medium to identify peribiliary metastasis.

METHODS

We identified 35 subjects with histological proven peribiliary metastases who underwent CEUS, CT and MR study. Four radiologists evaluated the presence of peribiliary lesions, using a 4-point confidence scale. Echogenicity, density and T1-Weigthed (T1-W), T2-W and Diffusion Weighted Imaging (DWI) signal intensity as well as the enhancement pattern during contrast studies on CEUS, CT and MR so as hepatobiliary-phase on MRI was assessed.

RESULTS

All lesions were detected by MR. CT detected 8 lesions, while US/CEUS detected one lesion. According to the site of the lesion, respect to the bile duct and hepatic parenchyma: 19 (54.3%) were periductal, 15 (42.8%) were intra-periductal and 1 (2.8%) was periductal-intrahepatic. According to the confidence scale MRI had the best diagnostic performance to assess the lesion. CT obtained lower diagnostic performance. There was no significant difference in MR signal intensity and contrast enhancement among all metastases (p>0.05). There was no significant difference in CT density and contrast enhancement among all metastases (p>0.05).

CONCLUSIONS

MRI is the method of choice for biliary tract tumors but it does not allow a correct differential diagnosis among different histological types of metastasis. The presence of biliary tree dilatation without hepatic lesions on CT and US/CEUS study may be an indirect sign of peribiliary metastases and for this reason the patient should be evaluated by MRI.

Peribiliary liver metastases MR findings

We described magnetic resonance (MR) features of peribiliary metastasis and of periductal infiltrative cholangiocarcinoma. We assessed 35 patients, with peribiliary lesions, using MR 4-point confidence scale. T1-weighted (T1-W), T2-weighted (T2-W) and diffusion-weighted images (DWI) signal intensity, enhancement pattern during arterial, portal, equilibrium and hepatobiliary phase were assessed. We identified 24 patients with periductal-infiltrating cholangiocellular carcinoma. The lesions in 34 patients appeared as a single tissue, while in a single patient, the lesions appeared as multiple individual lesions. According to the confidence scale, the median value was 4 for T2-W, 4 for DWI, 3.6 for T1-W in phase, 3.6 for T1-W out phase, 3 for MRI arterial phase, 3.2 for MRI portal phase, 3.2 for MRI equilibrium phase and 3.6 for MRI hepatobiliary phase. According to Bismuth classification, all lesions were type IV. In total, 19 (54.3%) lesions were periductal, 15 (42.9%) lesions were intraperiductal, and 1 (2.8%) lesion was periductal intrahepatic. All lesions showed hypointense signal in T1-W and in ADC maps and hyperintense signal in T2-W and DWI. All lesions showed a progressive contrast enhancement. There was no significant difference in signal intensity and contrast enhancement among all metastases and among all metastases with respect to CCCs, for all imaging acquisitions (p value >0.05). MRI is the method of choice for biliary tract tumors thanks to the possibility to obtain morphological and functional evaluations. T2-W and DW sequences have highest diagnostic performance. MRI does not allow a correct differential diagnosis among different histological types of metastasis and between metastases and CCC.

Evaluation and management of intrahepatic and extrahepatic cholangiocarcinoma

Cholangiocarcinomas are rare biliary tract tumors that are often challenging to diagnose and treat. Cholangiocarcinomas are generally categorized as intrahepatic or extrahepatic depending on their anatomic location. The majority of patients with cholangiocarcinoma do not have any of the known or suspected risk factors and present with advanced disease. The optimal evaluation and management of patients with cholangiocarcinoma requires thoughtful integration of clinical information, imaging studies, cytology and/or histology, as well as prompt multidisciplinary evaluation. The current review focuses on recent advances in the diagnosis and treatment of patients with cholangiocarcinoma and, in particular, on the role of endoscopy, surgery, transplantation, radiotherapy, systemic therapy, and liver-directed therapies in the curative or palliative treatment of these individuals. Cancer 2016;122:1349-1369. © 2016 American Cancer Society.

The Role of Endoscopy in the Diagnosis and Management of Cholangiocarcinoma

Cholangiocarcinomas (CCAs) are associated with poor overall survival, and majority of the tumors are unresectable at the time of diagnosis. Early diagnosis at a resectable stage is essential for improved outcomes. Noninvasive imaging plays an important role in evaluating patients with biliary obstruction, but is limited due to the lack of tissue sampling and in many cases due to the absence of a mass, especially for extrahepatic CCAs. Endoscopic diagnosis is needed in majority of patients with CCA and the diagnostic yield depends on the tumor location as well as the expertise and experience of the endoscopist. Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound remain the most common endoscopic diagnostic tools although newer technologies including fluorescence in situ hybridization, single-operator cholangioscopy, confocal laser endomicroscopy, and intraductal ultrasound are being increasing used. Traditionally, the role of endoscopy has been mainly palliative and limited to biliary drainage in patients with obstructive jaundice, however, newer treatment options like photodynamic therapy and radiofrequency ablation have shown promise toward improved patient survival. Multidisciplinary approach that involves medical oncology, gastroenterology, radiology, and surgical oncology teams is imperative for improved outcomes. In this review, we will first review the diagnostic approach to CCAs including imaging and endoscopic methods followed by a discussion of different endoscopic techniques in management of patients after a diagnosis of CCA.

Radiological diagnosis in cholangiocarcinoma: Application of computed tomography, magnetic resonance imaging, and positron emission tomography

The purpose of radiological imaging in patients with suspected or known cholangiocarcinoma (CCA) is tumour detection, lesion characterization and assessment of resectability. Different imaging modalities are implemented complementary in the diagnostic work-up. Non-invasive imaging should be performed prior to invasive biliary procedures in order to avoid false positive results. For assessment of intraparenchymal tumour extension and evaluation of biliary and vascular invasion, MRI including MRCP and CT are the primarily used imaging modalities. The role of PET remains controversial with few studies showing benefit with the detection of unexpected metastatic spread, the differentiation between benign and malignant biliary strictures, and for discriminating post therapeutic changes and recurrent CCA.

Biliary strictures: diagnostic considerations and approach

Biliary strictures present a diagnostic challenge, especially when no etiology can be ascertained after laboratory evaluation, abdominal imaging and endoscopic retrograde cholangiopancreatography (ERCP) sampling. These strictures were traditionally classified as indeterminate strictures, although with advances in endoscopic techniques and better understanding of hepato-biliary pathology, more are being correctly diagnosed. The implications of missing a malignancy in patients with biliary strictures—and hence delaying surgery—are grave but a significant number of patients (up to 20%) undergoing surgery for suspected biliary malignancy can have benign pathology. The diagnostic approach to these patients involves detailed history and physical examination and depends on the presence or absence of jaundice, level of obstruction, and presence or absence of a mass lesion. While abdominal imaging helps to find the level of obstruction and provides a ‘road map' for further endoscopic investigations, tissue diagnosis is usually needed to make decisions on management. Initially ERCP was the only modality to investigate these strictures but now, with the development of endoscopic ultrasound with fine needle aspiration and the availability of newer techniques such as intraductal ultrasound, single-operator cholangioscopy and confocal laser endomicroscopy, the diagnostic approach to biliary strictures has changed significantly. In this review, we will focus on the decision-making process for patients with biliary strictures and discuss the key decision points that should dictate further diagnostic investigations at each step.

Gadoxetic acid-enhanced MRI with MR cholangiography for the preoperative evaluation of bile duct cancer

PURPOSE

To assess the diagnostic accuracy of gadoxetic acid-enhanced biliary MRI with MR cholangiography (MRC) in the preoperative evaluation of bile duct cancer (BDC) staging and resectability.

MATERIALS AND METHODS

Seventy-three patients with BDC who underwent gadoxetic acid-enhanced biliary MRI and MRC, were included in this study. Two abdominal radiologists evaluated the biliary MRI findings regarding the tumor extent, vascular involvement, lymph node metastasis, and tumor resectability. The results were compared with the surgical and pathology findings which were used as the standard reference. The diagnostic performance of the MRI was evaluated using receiver operating characteristics (ROC) analysis. In addition, to determine whether the hepatobiliary phase images had been successfully obtained, the enhancement percentage of the hepatic parenchyma was measured on the portal venous images (PVI) and hepatobiliary phase images (HBPI), respectively.

RESULTS

The overall accuracy of the two reviewers for determining the tumor resectability was 61.6% and 83.5%, respectively. The Az values were 0.802 for reviewer 1 and 0.892 for reviewer 2 in the evaluation of the secondary biliary confluence tumor involvement and 0.773 for reviewer 1 and 0.846 for reviewer 2 in the evaluation of the intrapancreatic bile duct involvement. In the evaluation of the vascular involvement, the Az values were 0.718 and 0.906, respectively, for the hepatic artery evaluation and 0.55 and 0.88, respectively, for the portal vein evaluation. For assessment of lymph node metastasis, the overall accuracy was 69.6% and 79.7%, respectively. The mean enhancement percentages of hepatic parenchyma on PVI and HBPI were 39.3% and 65.9%, respectively (P % 0.05), and 49 of 73 patients (67.1%) showed higher enhancement percentage on HBPI than on PVI CONCLUSION: Gadoxetic acid-enhanced MRI with MRC is a reliable diagnostic method for assessing the tumor extent and resectability of BDC.

Focal intrahepatic strictures: a review of diagnosis and management

INTRODUCTION

Focal intrahepatic strictures are becoming more common owing to more prevalent and accurate cross-sectional imaging. However, data relating to their management are lacking. The purpose of the present review was to synthesize the current evidence regarding these lesions and to formulate a strategy for diagnosis and management.

METHODS

A literature search of relevant terms was performed using Medline. References of papers were subsequently searched to obtain older literature.

RESULTS

Focal intrahepatic strictures involve segmental hepatic ducts and/or left and right main hepatic ducts during their intrahepatic course. Most patients are asymptomatic while the minority present with vague abdominal pain or recurrent sepsis and only rarely with jaundice. Investigations used to distinguish benign from malignant aetiologies include blood tests (CEA, Ca19.9), imaging studies [ultrasonography (US), computed tomography (CT), magnetic resonance cholangiopancreatography (MRCP) and fluorodeoxyglucose-positron emission tomography (FDG-PET)], endoscopic modalities [endoscopic retrograde cholangiopancreatography (ERCP)/endoscopic ultrasound (EUS)/cholangioscopy] and tissue sampling (brush cytology/biopsy).

CONCLUSIONS

A focal intrahepatic stricture requires thorough investigation to exclude malignancy even in patients with a history of biliary surgery, hepatolithiasis or parasitic infection. If during the investigative process a diagnosis or suspicion of malignancy is demonstrated then surgical resection should be performed. If all diagnostic modalities suggest a benign aetiology, then cholangioscopy with targeted biopsies should be performed.

Surgical strategy for bile duct cancer: Advances and current limitations

The aim of this review is to describe recent advances and topics in the surgical management of bile duct cancer. Radical resection with a microscopically negative margin (R0) is the only way to cure cholangiocarcinoma and is associated with marked survival advantages compared to margin-positive resections. Complete resection of the tumor is the surgeon's ultimate aim, and several advances in the surgical treatment for bile duct cancer have been made within the last two decades. Multidetector row computed tomography has emerged as an indispensable diagnostic modality for the precise preoperative evaluation of bile duct cancer, in terms of both longitudinal and vertical tumor invasion. Many meticulous operative procedures have been established, especially extended hepatectomy for hilar cholangiocarcinoma, to achieve a negative resection margin, which is the only prognostic factor under the control of the surgeon. A complete caudate lobectomy and resection of the inferior part of Couinaud's segment IV coupled with right or left hemihepatectomy has become the standard surgical procedure for hilar cholangiocarcinoma, and pylorus-preserving pancreaticoduodenectomy is the first choice for distal bile duct cancer. Limited resection for middle bile duct cancer is indicated for only strictly selected cases. Preoperative treatments including biliary drainage and portal vein embolization are also indicated for only selected patients, especially jaundiced patients anticipating major hepatectomy. Liver transplantation seems ideal for complete resection of bile duct cancer, but the high recurrence rate and decreased patient survival after liver transplant preclude it from being considered standard treatment. Adjuvant chemotherapy and radiotherapy have a potentially crucial role in prolonging survival and controlling local recurrence, but no definite regimen has been established to date. Further evidence is needed to fully define the role of liver transplantation and adjuvant chemo-radiotherapy.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Gadobutrol-enhanced, three-dimensional, dynamic MR imaging with MR cholangiography for the preoperative evaluation of bile duct cancer

PURPOSE

To evaluate the diagnostic performance of 1.0-M gadobutrol-enhanced, 3-dimensional (3D), dynamic MR images with 3D-MR cholangiography (MRC) in the preoperative evaluation of bile duct cancer staging and resectability.

MATERIALS AND METHODS

Our institutional review board approved this retrospective study. Sixty patients (46 male, 14 female; mean age 65.9 years; range, 45-77 years) with surgically and pathologically proven bile duct cancers, were included in this study. Two gastrointestinal radiologists evaluated the biliary MR images, including 3D-MRC and gadobutrol-enhanced, dynamic images, using a 3D-gradient echo (GRE) technique, regarding the longitudinal tumor extent, vascular involvement of the bile duct cancer, lymph node metastasis, and tumor resectability. The results were compared with the surgical and pathology findings used as the reference standards.

RESULTS

The area under the receiver operating characteristic curve (Az) of the 2 reviewers was 0.95 and 0.93, respectively, for evaluation of the involvement of both secondary biliary confluences and 0.85 and 0.84, respectively, for assessment of the intrapancreatic duct. For determining the tumor resectability, the overall accuracy was 0.93 and 0.88, respectively, whereas for assessment of the vascular involvement, the Az values were 0.92 for reviewer 1 and 0.70 for reviewer 2 for the portal vein evaluation, and 0.99 for reviewer 1 and 0.76 for reviewer 2 for the hepatic artery evaluation. In the assessment of lymph node metastasis, the overall accuracy was approximately 0.77 for each reviewer.

CONCLUSION

One-molar, gadobutrol-enhanced, dynamic imaging, using a 3D-GRE technique with isotropic 3D-MRC showed excellent diagnostic capability for assessing the longitudinal extent and tumor resectability of bile duct cancer, although it generally underestimated the tumor involvement of vessels and lymph nodes.

The role of (18)F-fluorodeoxyglucose positron emission tomography in the diagnosis, staging, and follow-up of cholangiocarcinoma

(18)F-Fluorodeoxyglucose positron emission tomography ((18)FDG-PET) is a new diagnostic technique for the diagnosis and staging of cholangiocarcinoma. For diagnosis of a primary cholangiocarcinoma, (18)FDG-PET seems to be helpful to discriminate between malignant and benign lesions. However, the accuracy of (18)FDG-PET seems to be dependent on the anatomic location, growth pattern, and pathologic characteristics of the lesion. It has been proved that the accuracy of (18)FDG-PET is limited to detection of extrahepatic, infiltrating, and mucinous cholangiocarcinomas. Due to its lower sensitivity, (18)FDG-PET provides complementary rather than confirmative information in the diagnosis of regional lymph node metastasis. In contrast, it has high accuracy in detecting unsuspected distant metastases. The role of (18)FDG-PET in detecting cancer recurrence, monitoring treatment response, and predicting prognosis is still controversial.

[Cholestasis and liver dysfunction in critical care patients]

Cornerstones of the diagnostic investigations of disturbances in liver function are analysis and sophisticated evaluation of serum liver enzymes, bilirubin and ammonia. Coagulation factors, serum albumin and cholinesterase levels are indicators of the hepatic metabolic capacity. Dynamic assessment of complex liver functions allows quantification of the hepatic metabolic activity and excretory function. Imaging techniques permit visualization of the size and texture of the liver, the vascular supply and perfusion as well as an assessment of the gall bladder and the extra-hepatic and intra-hepatic bile ducts. Manifold causes for cholestasis and/or liver dysfunction are known, such as ventilation with high pressure, total parenteral nutrition, shock, hypoxia and certain drugs. Obstructive cholestasis requires reconstitution of bile duct drainage, while non-obstructive cholestasis primarily requires treatment of the causative disease. The symptomatic therapy of liver insufficiency is rarely possible via direct treatment of the cause, but mostly requires specific management of secondary organ dysfunctions related to hepatic dysfunction including circulatory failure, hepatorenal syndrome and hepatic encephalopathy. In rare cases a temporary liver surrogate is necessary. The molecular absorbent recirculating system (MARS), a form of extracorporeal albumin dialysis, is introduced as a modality for the treatment of liver failure.

Hilar cholangiocarcinoma: role of preoperative imaging with sonography, MDCT, MRI, and direct cholangiography

OBJECTIVE

The purpose of this article is to describe the roles of sonography, MDCT, MRI, and direct cholangiography in the evaluation of hilar cholangiocarcinoma.

CONCLUSION

Hilar cholangiocarcinoma is a primary malignant tumor typically located at the confluence of the right and left ducts within the porta hepatis. Staging of hilar cholangiocarcinoma with various imaging techniques is crucial for management, and a comprehensive approach is needed for accurate preoperative assessment.

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.

Obstructive jaundice in polycystic liver disease related to coexisting cholangiocarcinoma

Although jaundice rarely complicates polycystic liver disease (PLD), secondary benign or malignant causes cannot be excluded. In a 72-year-old female who presented with increased abdominal girth, dyspnea, weight loss and jaundice, ultrasound and computed tomography confirmed the diagnosis of PLD by demonstrating large liver cysts causing extrahepatic bile duct compression. Percutaneous cyst aspiration failed to relief jaundice due to distal bile duct cholangiocarcinoma, suspected by magnetic resonance cholangiopancreatography (MRCP) and confirmed by endoscopic retrograde cholangiopancreatography (ERCP). Coexistence of PLD with distal common bile duct cholangiocarcinoma has not been reported so far.

MR imaging and MR cholangiopancreatography in the preoperative evaluation of hilar cholangiocarcinoma: correlation with surgical and pathologic findings

The primary aim was to evaluate delayed contrast-enhanced MRI in depicting perineural spread of hilar cholangiocarcinoma (CCC) and consequently to determine the capability of MRI/MRCP for staging CCC. Fifteen patients that underwent MRI/MRCP and surgical treatment were retrospectively included. Two radiologists evaluated MR images to assess delayed periductal enhancement, extent of bile duct stenosis, liver parenchymal and vascular involvement and presence of liver atrophy. An agreement between delayed enhancement of the bile duct walls and perineural neoplastic spread showed a very good correlation factor (0.93). The overall accuracy in detecting biliary neoplastic invasion was higher for delayed T1-weighted images (93.3%) than for the MRCP images (80%), and T1-delayed image increased the MR accuracy in assessing the neoplastic resectability (p<0.05). MRI correctly predicted vascular involvement in 73% and liver involvement in 80% of the cases. The number of overall correctly assessed patients with regard to resectability was 11 true positive, 1 false positive and 3 true negative. The combination of MRI/MRCP is a reliable diagnostic method for staging hilar cholangiocarcinomas. Delayed periductal enhancement is accurate in the evaluation of neoplastic perineural spread, and it can improve diagnostic accuracy to identify resectable and unresectable tumours.

Comparison of early and delayed FDG PET for evaluation of biliary stricture

OBJECTIVE

We assessed whether delayed FDG PET imaging is more useful for the evaluation of biliary stricture in differential diagnosis of malignancy from benign disease.

METHODS

Thirty-seven patients who underwent FDG PET for differential diagnosis of the disease causing biliary stricture were included. FDG PET imaging was performed at 70+/-12 min (early) post FDG injection and repeated 188+/-27 min (delayed) after injection only in the abdominal region. Image analysis was performed with visual interpretation and using a semi-quantitative method if lesion was visible on the PET image. The semi-quantitative analysis using the standardized uptake value (SUV) was determined for both early and delayed images (SUVearly and SUVdelayed, respectively). The tumour-to-normal liver (T/L) ratio was also calculated.

RESULTS

The final diagnosis was cholangiocarcinoma in 29 and benign disease in eight patients. In cases of cholangiocarcinoma, visual analysis of FDG PET using the delayed images, improve the diagnosis with one more patient correctly identified. For early and delayed FDG PET, sensitivities were 82.8% and 86.2%, respectively; specificities were 87.5% for both; and accuracies were 83.8% and 86.5%, respectively. Both SUV and T/L ratio derived from delayed images were significantly higher than those derived from early images for cholangiocarcinoma (P<0.0002 and P<0.0001, respectively).

CONCLUSION

FDG PET could be useful for differential diagnosis of malignancy from benign disease in patients with biliary stricture. Especially, the delayed targeted FDG PET imaging can be recommended in those patients when early imaging is negative or equivalent, because of increased lesion uptake and increased lesion to background contrast ratio.

Evaluation of the longitudinal tumor extent of bile duct cancer: value of adding gadolinium-enhanced dynamic imaging to unenhanced images and magnetic resonance cholangiography

OBJECTIVE

To determine the added value of gadolinium-enhanced dynamic magnetic resonance (MR) images compared with unenhanced and MR cholangiography (MRC) images, to evaluate the longitudinal extension of bile duct cancer.

MATERIALS AND METHOD

Thirty-three patients with hilar cholangiocarcinoma or common duct cancer who had undergone MRC, unenhanced, and gadolinium-enhanced dynamic MR images and surgery were included in this study. Two experienced radiologists independently reviewed 2 image sets in 2 steps, that is, the MRC set (unenhanced and MRC) and the combined image set (MRC set with dynamic images). At each step, the readers determined the tumor status according to the Bismuth-Corlette classification. The readers assigned their confidence levels on a 5-point scale regarding whether the tumor involved the secondary confluence of the bile duct and the intrapancreatic common bile duct. The radiologists' diagnostic confidence of the 2 image sets was analyzed using receiver operating characteristic analysis.

RESULTS

Receiver operating characteristic analysis showed higher areas under the curve values when the combined image set was interpreted (0.990 +/- 0.017 for reader 1 and 0.951 +/- 0.027 for reader 2) than when the MRC set was interpreted (0.982 +/- 0.017 for reader 1 and 0.902 +/- 0.038 for reader 2); however, the difference was not statistically significant for either reader (P > 0.05). In addition, regarding evaluation of the tumor status according to the Bismuth-Corlette classification, the overall accuracy was higher for the combined image set than for the MRC set alone, but the difference was not significant (P > 0.05). When dynamic images were added to the MRC images, interobserver agreement improved from 0.72 to 0.84.

CONCLUSIONS

The addition of contrast-enhanced dynamic images to unenhanced and MRC images did not significantly improve the diagnostic accuracy for assessment of the longitudinal extent of bile duct cancer.

A pilot study of bendamustine in advanced bile duct cancer

We performed a pilot study to evaluate the safety and tolerability of bendamustine in patients with advanced hilar bile duct cancer and impaired liver function. Six patients with histologically proven, unresectable adenocarcinoma of the hilar bile duct were treated with bendamustine 140 mg/m intravenously on day 1 of the first cycle and with bendamustine 100 mg/m on days 1 and 2 of the second to fourth cycle. Treatment cycles were repeated every 21 days. Primary endpoint was the safety and tolerability of the treatment; secondary endpoints were response rate, time to progression and overall survival. Transient lymphopenia grade 3 occurred in all six patients. No other grade 3 or 4 toxicities were present. The most common nonhematologic toxicity was mouth dryness grade 2 in six patients. Three patients had stable disease. No partial or complete responses were observed. Median time to progression was 3.3 months; median overall survival was 6 months. Our study demonstrates that bendamustine can be safely administered in patients with hilar bile duct cancer and impaired liver function. A potential role of bendamustine in combination therapies for bile duct cancer will be a subject of further trials.

[F-18]fluorodeoxyglucose positron emission tomography and positron emission tomography: computed tomography in recurrent and metastatic cholangiocarcinoma

OBJECTIVES

We retrospectively assessed the diagnostic utility of dedicated positron emission tomography (PET) and hybrid PET-computed tomography (CT) scans with [F-18]fluorodeoxyglucose (FDG) in the imaging evaluation of patients with known or suspected recurrent and metastatic cholangiocarcinoma.

METHODS

The study group included 24 patients (13 males and 11 females; age range, 34-75 years) with known or suspected recurrent and metastatic cholangiocarcinoma. We performed 8 dedicated PET scans (Siemens 953/A, Knoxville, Tenn) in 8 patients and 24 hybrid PET-CT scans (Siemens Biograph, Knoxville, Tenn) in 16 patients. Four patients underwent both pretreatment and posttreatment scans. Nonenhanced CT transmission scans were obtained for attenuation correction after administration of oral contrast material. PET images were obtained 60 minutes after the intravenous administration of 15 mCi (555 MBq) FDG. Prior treatments included surgery alone in 12 patients, surgery and chemotherapy in 6 patients, and surgery and combined chemoradiation therapy in 6 patients. Diagnostic validation was conducted through clinical and radiologic follow-up (2 months to 8 years).

RESULTS

PET and CT were concordant in 18 patients. PET-CT correctly localized a hypermetabolic metastatic lesion in the anterior subdiaphragmatic fat instead of within the liver and was falsely negative in intrahepatic infiltrating type cholangiocarcinoma. PET was discordant with CT in 6 patients. PET was negative in an enlarged right cardiophrenic lymph node on CT, which remained stable for 1 year. In 1 patient, PET-CT scan showed hypermetabolic peritoneal disease in the right paracolic gutter without definite corresponding structural abnormalities, which was subsequently confirmed on a follow-up PET-CT scan performed 6 months after the initial study, at which time peritoneal nodular thickening was evident on concurrent CT. PET-CT documented the progression of locally recurrent and metastatic disease in another patient based on interval appearance of several new hypermetabolic lesions and significant increase in the standardized uptake values of the known lesions despite little interval change in the size and morphologic character of lesions on concurrent CT. It was also helpful in excluding metabolically active disease in patients with contrast enhancement at either surgical margin of hepatic resection site or focally within hepatic parenchyma and in an osseous lesion. Overall, based on the clinically relevant patient basis for detection of recurrent and metastatic cholangiocarcinoma, the sensitivity and specificity of PET (alone and combined with CT) were 94% and 100% and, for CT alone, were 82% and 43%, respectively.

CONCLUSIONS

FDG PET and PET-CT are useful in the imaging evaluation of patients with cholangiocarcinoma (except for infiltrating type) for detection of recurrent and metastatic disease and for assessment of treatment response. In particular, the combined structural and metabolic information of PET-CT enhances the diagnostic confidence in lesion characterization.

Assessment of hilar and extrahepatic bile duct cancer using multidetector CT: value of adding multiplanar reformations to standard axial images

To retrospectively assess the value of multiplanar reformations (MPRs) compared with standard axial images in the assessment of hilar and extrahepatic bile duct cancer. Forty-eight patients with confirmed bile duct cancer were included as preoperative work-ups; all of these patients underwent contrast-enhanced multidetector CT consisting of axial and MPR images. Two radiologists independently assessed the axial images alone and the combined axial and MPR images in the coronal and sagittal planes for the presence of tumor, its extent, vascular involvement, and resectability. The results were compared with surgical and pathologic findings. For tumor presence and conspicuity, combined axial and MPR images had higher values than the axial only images. For evaluation of tumoral extent, there was no difference between the two image sets for either reader. The accuracy for tumor extent was lower in hilar cancer than in extrahepatic bile duct cancer. For evaluation of vascular involvement and resectability, the area under the receiver operating characteristic curve of axial images was not significantly different from that of the reformatted images. The addition of MPR images to the standard axial images did not significantly improve the diagnostic performance of MDCT in the evaluation of the bile duct cancer.

What is the current state-of-the-art imaging for detection and staging of cholangiocarcinoma?

Cholangiocarcinoma is an adenocarcinoma that arises from the bile duct epithelium and is the second most common primary hepatobiliary cancer, after hepatocellular cancer, with approximately 2,500 cases annually in the U.S. However, cholangiocarcinoma remains a relatively rare disease, accounting for <2% of all human malignancies. Although the entire biliary tree is potentially at risk, tumors involving the biliary confluence or the right or left hepatic ducts (hilar cholangiocarcinoma) are most common and account for 40%-60% of all cases. Most patients present with advanced disease that is not amenable to surgical treatment. The median survival time for patients with intrahepatic cholangiocarcinoma without involvement of the hilum varies among centers from 18-30 months. The median survival time for patients with perihilar cholangiocarcinoma is slightly less, varying from 12-24 months. Despite the overall poor prognosis, survival after surgical treatment of hilar cholangiocarcinoma has improved during the past 10-15 years. This review highlights the imaging features of cholangiocarcinoma, with particular emphasis on the imaging techniques that can best assess tumor resectability and guide the surgeon regarding the potential extent of resection required in operable candidates.

Differential diagnosis of proximal biliary obstruction

BACKGROUND

Obstruction at the hepatic duct confluence is generally due to hilar cholangiocarcinoma (HCCA). However, in up to 15% of patients, hilar obstruction could be due to alternative diagnoses other than HCCA. The aim of this study was to determine preoperative criteria that could differentiate HCCA from the alternative diagnoses.

METHODS

All patients with hilar obstruction presumed to represent HCCA were included (1997-2001). The extent of disease was assessed preoperatively with computed tomography, magnetic resonance cholangiopancreatography, and Duplex ultrasonography, and these findings were correlated to the final histopathology.

RESULTS

A total of 171 patients were included in the study, with HCCA being the most common diagnosis (141 patients [82.4%], group I). Alternative diagnoses other than HCCA were encountered in 30 patients (17.5%, group II) and included benign stricture (9 patients [5.2%]) and other malignancy (21 patients [12%]). There was a higher incidence of involvement of the second-order bile ducts in group I (26% vs 3% in group II, P<.01). Vascular involvement and lobar atrophy were more common in group I (58% and 41%) when compared with group II (16% and 6%, P<.005 and P<.002). The combination of these 2 findings (vascular invasion+lobar atrophy) was reliable for discriminating patients with HCCA from the alternative diagnoses. (38% in group I and 3.3% in group II, P<.001).

CONCLUSIONS

Involvement of second-order bile ducts, vascular invasion, and lobar atrophy are more likely in patients with HCCA. The combination of vascular invasion and lobar atrophy significantly increases the diagnostic likelihood of HCCA. The absence of these findings should raise awareness of the possibility of an alternative diagnosis.

Preoperative staging accuracy of multidetector row computed tomography for extrahepatic bile duct carcinoma

PURPOSE

This study sought to evaluate the accuracy of multidetector computed tomography (MDCT) for preoperative staging of extrahepatic bile duct (EHD) carcinoma and to assess the value of coronal reformations from isotropic voxels.

MATERIALS AND METHODS

Thirty patients with surgically proven EHD cancer underwent dynamic MDCT with coronal reformation. Two experienced radiologists independently evaluated contrast-enhanced dynamic transverse CT images (axial approach) and combined transverse and coronal images (combined approach). The radial extent (TNM staging) and the vertical extent of tumors were assessed and correlated with pathological findings of surgical specimen.

RESULTS

All of primary tumors were detected by axial and combined CT imaging (100%). Overall accuracy of the T staging was 73% (22/30) with axial and 77% (23/30) with combined CT imaging (P>0.05). The accuracy of N staging was 57% (17/30) with axial and 63% (19/30) with combined CT imaging (P>0.05). The accuracy of M staging was 97% (29/30) with both axial and combined CT imaging. Upper margin accuracy was 97% (29/30) for axial and 100% for combined CT imaging (P>0.05), whereas that of the lower margin was 90% (27/30) for axial and 93% (28/30) for combined CT imaging (P>0.05).

CONCLUSIONS

Multidetector computed tomography was sufficiently accurate for evaluating the vertical extents, but radial extents of EHD cancer. The addition of coronal reformatted images did not improve the accuracy for staging of EHD cancer.

[Value of radiological methods in the diagnosis of biliary diseases]

The modern cross-sectional radiological methods of ultrasound, computed tomography, and magnetic resonance imaging provide manifold possibilities for the diagnosis of inflammatory and tumorous diseases of the gallbladder and the bile ducts as well as stone-related diseases. The invasive methods for direct imaging of the bile ducts, such as endoscopic retrograde cholangiopancreatography, are mainly used within therapeutic concepts. According to the literature, ultrasound and magnetic resonance imaging show a sensitivity of up to 100% in the diagnosis of intra- and extrahepatic cholestasis, but concerning the diagnosis of the cause of cholestasis these methods are limited. Therefore, additional MRI sequences or computed tomography are necessary. Computed tomography is particularly efficient for the diagnosis of the biliary system and adjacent anatomical and pathological structures within the pre- and postoperative period.

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.

Staging of Klatskin tumours (hilar cholangiocarcinomas): comparison of MR cholangiography, MR imaging, and endoscopic retrograde cholangiography

The aim of the study was to compare prospectively magnetic resonance cholangiography (MRC) and magnetic resonance imaging (MRI) with endoscopic retrograde cholangiography (ERC) in the diagnosis and staging of Klatskin tumours of the biliary tree (hilar cholangiocarcinomas). Forty-six patients with suspected Klatskin tumours of the biliary tract underwent MRI and heavily T2-weighted, non-breathhold, respiratory-triggered fast spin-echo MRC. Forty-two patients underwent ERC within 24 h; in four patients, ERC was not feasible, and percutaneous trans-hepatic cholangiography (PTC) was carried out instead. Two independent investigators evaluated imaging results for the presence of tumour, bile duct dilatation, and stenosis. Clinical and histopathological correlation revealed Klatskin tumours in 33 patients. MRI revealed a slightly hyperintense signal of infiltrated bile ducts in T2-weighted fast spin-echo sequences. The malignant lesion was regularly visualized as a hypointense area in T1-weighted gradient-echo sequences with substantial contrast enhancement along the involved bile duct walls. MRC revealed the location and extension of the tumour in 31 of 33 cases correctly (sensitivity 94%, specificity 100%, diagnostic accuracy 95%). In 27 of 31 cases, ERC enabled accurate staging and diagnosis of Klatskin tumours with a sensitivity of 87%. ERC and PTC combined yielded a sensitivity of 84% and a specificity of 97%. Tumours were grouped according to the Bismuth classification, with MRC allowing correct identification of type I tumour in seven patients, type II tumour in four patients, type III tumour in 12 patients, and type IV tumour in ten patients. MRC provided superior visualization of completely obstructed peripheral systems. MRC in combination with MRI is a reliable non-invasive diagnostic method for the pre-therapeutic staging of Klatskin tumours.

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.

Biliary ductal evaluation of hilar cholangiocarcinoma: three-dimensional direct multi-detector row CT cholangiographic findings versus surgical and pathologic results--feasibility study

The study was conducted, with institutional review board approval and informed patient consent, to assess the feasibility and diagnostic effectiveness of three-dimensional direct multi-detector row computed tomographic (CT) cholangiography for determining the extent of bile duct invasion by hilar cholangiocarcinoma. Eleven patients underwent contrast material-enhanced direct multi-detector row CT cholangiography of the primary and secondary biliary confluence levels and then surgical resection. In most patients, CT cholangiography was tolerable and yielded excellent or good opacification of the biliary tree. CT cholangiography enabled a correct diagnosis of the extent of ductal involvement at all 11 primary confluence levels and at 18 of the 19 secondary confluence levels. Three secondary confluences, which could not be analyzed owing to nonopacification or poor opacification, proved to be involved by hilar cholangiocarcinoma. The authors conclude that three-dimensional direct multi-detector row CT cholangiography is accurate and feasible for defining the extent of ductal invasion by hilar cholangiocarcinoma, especially in patients with preliminary biliary drainage.

[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.

Vergleich von 2D- und 3D-Sequenzen für die MRCP

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements.

State-of-the-art computed tomographic and magnetic resonance imaging of the gastrointestinal system

Among the major innovations in radiology of the gastrointestinal (GI) system are the replacement of classic invasive diagnostic methods with noninvasive ones and the improvement in lesion characterization and staging of pancreatobiliary malignancies. Developments in imaging technology have led to many improvements in the field of diagnostic GI radiology. With its fast and thin-section scanning abilities, multidetector-row CT (MDCT) strengthens the place of CT as the most efficient tool to diagnose, characterize, and preoperatively stage pancreatic neoplasms. MR cholangiopancreatography has widely replaced endoscopic retrograde cholangiopancreatography in the diagnosis and staging of pancreatobiliary malignancies. MR imaging, using phased-array or endorectal coils, demonstrates local tumor invasion accurately in rectal cancers and thus allows an improved surgical planning. Virtual colonoscopy with MDCTs is an efficient screening method for colon cancer, and MDCT enterography is becoming the standard imaging technique for many small bowel disorders. The continuing developments in CT and MR technology will most probably further improve the accuracy of these and other imaging applications in the near future.

Assessment of MRI and MRCP in diagnosis of biliary cystadenoma and cystadenocarcinoma

Magnetic resonance imaging (MRI) and magnetic resonance cholangio-pancreatography (MRCP) features were analyzed in the diagnosis of seven surgically resected hepatobiliary cystic tumors with reference to histopathological data. Homogeneity, size, location, signal intensity, presence or absence of septa and/or nodules and MRCP features of the lesions were studied. Histological evidence demonstrated six biliary cystadenoma (BCA) including four pseudo-ovarian stroma (POS) and one biliary cystadenocarcinoma (BCAC). Cystic lesions (3-15 cm in diameter) were homogeneous in the six BCA, heterogeneous in the one BCAC, and were located in the left and right liver, respectively. On T2-weighted images all lesions were hyperintense. On T1-weighted images hypointensity was found in three BCA (all serous fluid, including one POS), isointensity was found in the three others (two mucinous and one hemorrhagic fluid, including three POS) and in the one BCAC (containing mucinous fluid). Septas were present in all cases and nodules only in the one BCAC. On MRCP a hyperintense cystic lesion was found in all cases and a bile ducts dilatation in two BCA and the one BCAC. Gadolinium-enhanced MRI in combination with MRCP is a valuable tool for the diagnosis of BCA or BCAC. However, no specific information is gained for POS detection.