Abnormalities of the Distal Common Bile Duct and Ampulla: Diagnostic Approach and Differential Diagnosis Using Multiplanar Reformations and 3D Imaging

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1 Gastrointestinal Imaging Review Raman and Fishman CT of the Distal CD and mpulla Gastrointestinal Imaging Review FOCUS ON: Siva P. Raman 1 Elliot K. Fishman Raman SP, Fishman EK Keywords: 3D imaging, ampulla, ampullary carcinoma, common bile duct, CT, pancreatic adenocarcinoma DOI: /JR Received May 24, 2013; accepted after revision July 2, oth authors: Department of Radiology, Johns Hopkins University, 601 N Caroline St, JHOC 3251, altimore, MD ddress correspondence to S. P. Raman (srsraman3@gmail.com). This article is available for credit. JR 2014; 203: X/14/ merican Roentgen Ray Society bnormalities of the Distal Common ile Duct and mpulla: Diagnostic pproach and Differential Diagnosis Using Multiplanar Reformations and 3D Imaging OJECTIVE. The distal common bile duct (CD) and ampulla are extremely difficult sites to evaluate on CT. This article seeks to provide the reader with a framework and algorithmic approach to the evaluation of abnormalities involving the distal CD and ampulla, including an emphasis on the use of multiplanar reformations and 3D imaging, the morphologic features on CT that suggest the presence of malignancy, and a differential diagnosis for abnormalities in this location. CONCLUSION. In our experience, both the distal CD and ampulla are common sites of missed diagnoses for radiologists. voiding mistakes in interpreting imaging findings in this location requires a systematic approach especially in the setting of unexplained biliary ductal dilatation. Rather than simply suggesting that MRCP or ERCP be performed for the ultimate diagnosis, radiologists can perform a careful CT evaluation using multiplanar reformations and 3D imaging to determine the correct diagnosis prospectively. timely and correct diagnosis is imperative because lesions in the ampulla and CD can be very aggressive despite their small size. T he distal common bile duct (CD) and ampulla can be an extremely challenging location for the radiologist to assess: It can be difficult not only to differentiate a normal distal CD with mild dilatation from a distal CD with true pathologic dilatation but also, even once an abnormality has been identified, to provide the appropriate differential diagnosis. The accurate radiologic evaluation of this location is of great importance because periampullary tumors are the third most common type of gastrointestinal neoplasm, after colonic and gastric tumors, and because the different lesions found in this location can have markedly different prognoses [1]. This article seeks to provide the reader with a framework for interpreting CT studies of the distal CD and ampulla, including providing a differential diagnosis for ampullary and distal CD abnormalities and lesions, a perspective on when a dilated CD requires further evaluation with MRCP or ERCP, and a discussion of the use of multiplanar reformations (MPRs) and 3D imaging to better assess the morphology of the distal CD and ampulla. Of course, many cas- es will ultimately require either MRCP or ERCP for further definitive evaluation, but an accurate interpretation of the initial CT examination may allow the radiologist to prospectively suggest the correct diagnosis. Evaluation of iliary Dilatation In general, the CD should measure 7 mm or less in healthy patients, although the normal duct may be dilated in older patients and those who have undergone cholecystectomy. Thus, overemphasizing CD measurements, especially when the ducts are only mildly dilated, should be avoided, particularly in patients without symptoms (i.e., biliary colic, right upper quadrant pain, jaundice) or biochemical markers suggestive of biliary obstruction [2]. In patients with borderline enlargement of the ducts without CT evidence of a discrete obstructing mass or other suspicious imaging features, the best course of action may be to simply recommend correlation with clinical and biochemical markers of obstruction rather than recommending MRCP or ERCP in every patient. Normal bile ducts on CT should have an almost imperceptible wall ( 1 mm), with only minimal enhancement on either arteri- JR:203, July

2 Raman and Fishman al or venous phase images. In the setting of dilated bile ducts, the ducts must be carefully evaluated for the presence of focal or diffuse hyperenhancement on arterial or venous phase images; delayed enhancement, if delayed images are acquired; focal or diffuse bile duct wall thickening; and a discrete mass. The same precepts traditionally used to analyze the bile ducts on ERCP are just as important to apply to CT as well: The CD should be carefully evaluated for discrete sites of transition between dilated proximal ducts and a decompressed or narrowed distal duct. Once a site of transition is found, any evidence of irregularity, abrupt narrowing, or shouldering at the transition point should raise suspicion for malignancy. lthough this evaluation can be performed using the source axial images, the use of coronal and sagittal MPR images and 3D reconstructions can be vital [3]. Technique In any patient with a suspected pancreatobiliary abnormality, a dual-phase study with both arterial and venous phase images should be acquired. The arterial phase images are used to identify hypervascular tumors (i.e., ampullary carcinoid, pancreatic neuroendocrine tumors, hypervascular gastrointestinal stromal tumors), subtle biliary tree mucosal hyperenhancement and thickening, and tumor neovascularity and to evaluate the arterial anatomy before surgery. The venous phase images are used to evaluate the liver and pancreas for traditionally hypovascular tumors and metastases, locoregional lymphadenopathy, and involvement of the venous vasculature by tumor [4]. lthough delayed images are not routinely acquired, they may be added to the protocol if cholangiocarcinoma is prospectively thought to be a diagnostic consideration. Positive oral contrast material absolutely must be avoided in patients presenting with jaundice or a suspected mass in the pancreas, ampulla, or duodenum: Not only will the positive contrast agent obscure any intraluminal mass in the duodenum or near the ampulla, but also streak artifact from the contrast agent will make evaluation of subtle duodenal wall thickening or hyperenhancement near the ampulla difficult to perceive and can interfere with 3D postprocessing algorithms. Instead, a neutral contrast agent such as water or a barium suspension (VoLumen, racco Diagnostics) should be used, and some portion of this contrast medium should be given to the patient immediately before scanning to maximize gastric and duodenal distention [4]. fter the acquisition of source axial images and reconstruction of standard MPRs, we have found three image postprocessing reconstruction algorithms (including 3D postprocessing) to be the most useful for image interpretation: volume rendering (VR), minimum intensity projections, and curved planar reformations. VR is a complex, computationally intensive computer algorithm that assigns a specific color and transparency to each voxel in a dataset on the basis of its attenuation and relationship to other adjacent voxels before presenting these data in a 3D display. The VR technique allows the best soft-tissue definition of any of the 3D reconstruction tools and is a vital component of biliary analysis. This technique is useful not only for increasing the conspicuity of obstructing lesions, but also for increasing the conspicuity of subtle biliary hyperenhancement and thickening [4, 5]. Minimum-intensity-projection reconstructions rely on the same principles as maximum-intensity-projection (MIP) imaging. However, unlike MIP reconstructions, which project the highest-attenuation voxels in a dataset, minimum-intensity-projection reconstructions project the lowest-attenuation voxels, making them extraordinarily valuable for visualization of fluid-filled structures, such as the biliary tree or pancreatic duct, particularly when these structures are dilated or obstructed. t our institution, although MIP images are not a major component of biliary tree 3D analysis, minimum-intensity-projection reconstructions are performed in every case, and we have experienced great success in identifying small tumors that were more conspicuous when using this imaging technique [6, 7]. Finally, given that the entire extrahepatic bile duct does not normally course in the coronal, sagittal, or axial plane, visualizing the entire duct on any given MPR or the source axial images can be impossible, making it more difficult to perceive sites of subtle wall thickening or even a discrete mass. Curved planar reformations, which are interactively created by the user as he or she identifies the course of the duct, allow the entire CD to be displayed in a single 2D image and are part of our routine evaluation [6, 8]. Differential Diagnosis Malignant Causes mpullary adenoma denomas of the small bowel are relatively uncommon compared with those of the large bowel, and within the small bowel, adenomas are more common in the ileum and jejunum than in the duodenum. Within the duodenum, 10% of all duodenal polyps are ultimately found to be adenomas, and the most common location is in proximity to the ampulla of Vater [9]. These lesions are most common in elderly patients, and other than familial adenomatosis coli, no other clear risk factors for the development of ampullary adenomas have been described in the literature [9]. mpullary adenomas are benign lesions that retain malignant potential: Similar to the adenoma-carcinoma sequence in the colon, these lesions usually contain foci of lowgrade dysplasia and have the potential to develop higher-grade dysplasia and invasive carcinoma, particularly as they grow larger. Up to 60% of ampullary adenomas are ultimately found to harbor at least some foci of invasive carcinoma (especially in large lesions), so the preoperative distinction between an adenoma and an ampullary carcinoma is not relevant for the radiologist [9]. There are no dedicated descriptions of the imaging appearance of ampullary adenomas in the literature to date; in our experience, although ampullary adenomas may have a slightly lesser predilection for causing severe ductal obstruction, their CT appearance is not significantly different from that of ampullary carcinomas (Figs. 1 and 2). Cholangiocarcinoma lthough cholangiocarcinomas of the extrahepatic duct have a strong predilection for the proximal one third of the duct, up to 20% of lesions occur in the distal one third and 95% of patients show ductal obstruction at the time of diagnosis [10]. Traditionally, both intrahepatic and extrahepatic cholangiocarcinomas have been classified into three different morphologic subtypes, each of which presents with a different appearance on imaging: mass-forming cholangiocarcinoma, periductal infiltrating cholangiocarcinoma, and intraductal cholangiocarcinoma. The mass-forming cholangiocarcinoma is the easiest of the three subtypes to diagnose: It usually presents as a discrete mass or nodule that obstructs the extrahepatic bile duct. This mass does not have to be particularly large to obstruct the duct, and both the source axial images and coronal MPRs should be scrutinized for evidence of a discrete nodule. Like intrahepatic cholangiocarcinoma, these lesions can show some hypervascularity on arterial phase images and 18 JR:203, July 2014

3 CT of the Distal CD and mpulla increased enhancement on delayed images, making multiphase protocols extremely useful for diagnosis [10, 11]. The periductal infiltrating variant can be more difficult to identify; it often presents as asymmetric bile duct wall thickening and enhancement at the site of transition in the dilated biliary tree and usually involves only a short segment. These tumors can rarely involve a larger segment of the bile duct, sometimes extending into the intrahepatic biliary tree, and can rarely be mistaken for an inflammatory process. In our experience, volume-rendered 3D images have proven to be extremely useful in identifying this variant of cholangiocarcinoma because they nicely accentuate sites of abnormal enhancement and thickening [10] (Figs. 3 5). Finally, the intraductal variant is quite rare and can have a variable morphology that is not readily distinguishable from the other two morphologic subtypes on CT. These lesions tend to spread along the inner surface of the bile duct, either as a superficially spreading mass that presents as focal wall thickening or as a discrete intraluminal polyploid mass [10]. mpullary carcinoma lthough radiologists often regard the ampulla as a single anatomic entity, it is actually a region composed of multiple different structures, the most important of which are the distal CD, downstream pancreatic duct, and duodenum. ccordingly, this region is composed of several different types of epithelium, including intestinal epithelium (duodenum), foveolarlike mucosa (papilla of Vater), and pancreatobiliary epithelium (distal CD and pancreatic duct) [12]. s a result, even though ampullary carcinomas are often thought of as a single pathologic entity, in reality they represent a heterogeneous group of tumors arising in the region of the ampulla that can have different biologic behaviors depending on their exact origin. In general, pathologists broadly divide these tumors into three groups: tumors arising from the duodenal epithelium of the ampulla, tumors arising from the pancreatobiliary epithelium of the distal CD or pancreatic duct, and intraampullary tumors showing histologic overlap with combined duodenal and pancreaticobiliary epithelial morphology. These three tumor types can have very different prognoses and biologic behavior. Intraampullary tumors tend to have the best prognosis, which may result from their origin within the ampulla and relatively earlier presentation because of a greater propensity for early, severe ductal obstruction and a lesser invasive component. lternatively, tumors arising from the pancreatobiliary epithelium tend to have a worse prognosis, with both histology and prognosis relatively similar to pancreatic adenocarcinoma. Finally, tumors arising from the duodenal mucosa tend to be large at presentation with a greater propensity for lymph node metastases but with a prognosis roughly comparable to duodenal adenocarcinoma [12]. Regardless of this pathologic distinction, these three subtypes cannot be reliably distinguished on any imaging modality including CT. Kim et al. [13] reported that ampullary carcinomas obstructed both the pancreatic and biliary ducts in 52% of cases and that 48% of cases showed only biliary ductal dilatation. These results likely reflect the different possible sites of origin for these tumors in the region of the ampulla and are concordant with our experience, which is that isolated dilatation of the pancreatic duct alone is extraordinarily rare. The lesion can appear as a discrete nodular mass or as ill-defined softtissue thickening near the ampulla. However, in our experience, even if a discrete mass or lesion is not perceptible, careful examination of the ampulla on coronal MPR or 3D images will often show an abrupt margin or irregularity at the site of transition in the CD, which should definitely precipitate further evaluation with ERCP [13 15] (Figs. 6 10). mpullary carcinoid lthough ampullary carcinoid tumors are rare, with fewer than 120 cases described in the literature, these neoplasms have an imaging appearance that may allow a more specific diagnosis [16]. Interestingly, ampullary carcinoids are thought to be biologically distinct from other smallbowel or duodenal carcinoid tumors, with ampullary carcinoids showing a higher predilection for metastatic disease [17]. These tumors tend to present as small lesions, can develop nodal disease even when the primary tumor is quite small, and almost never present with a hypersecretion syndrome [17]. Given the risk of aggressive behavior even with small lesions and their tendency to obstruct the biliary tree, these tumors invariably are treated with a pancreaticoduodenectomy (Whipple procedure) [18]. Like carcinoid and neuroendocrine tumors elsewhere in the bowel or the pancreas, ampullary carcinoid tumors (and their locoregional lymph node metastases) tend to be avidly enhancing on arterial phase images (Fig. 11). lthough the exact site of origin of the tumor may be in doubt, the presence of biliary and pancreatic ductal dilatation and a clear fat plane between the mass and the adjacent pancreatic head should allow the radiologist to prospectively suggest that the tumor arises from the ampulla rather than the pancreatic head or the adjacent duodenal wall. Pancreatic adenocarcinoma In some cases, differentiation of a primary pancreatic head or uncinate process adenocarcinoma from a primary ampullary neoplasm may be difficult: oth types of lesions can result in biliary and pancreatic ductal obstruction; both tend to be hypoenhancing relative to the normal pancreatic parenchyma; and the exact site of origin of a lesion may not be immediately evident, particularly with pancreatic adenocarcinomas primarily centered in the pancreaticoduodenal groove (an anatomic space that includes the ampulla) [4, 19]. However, the distinction between the two types of lesions may not be important given that both are treated with pancreaticoduodenectomy. In our experience, primary ampullary lesions, despite their involvement of the pancreatic duct, do not commonly result in upstream pancreatic atrophy, as is often the case with pancreatic adenocarcinoma (Figs ). Moreover, in some cases, a careful appraisal of the images, particularly in the coronal plane, may allow the radiologist to suggest that the lesion is centered in the pancreatic head rather than the ampulla. Periampullary duodenal carcinoma The duodenum and proximal jejunum are the most common sites for the development of smallbowel adenocarcinoma, accounting for 50 70% of lesions [19]. When these tumors arise in close proximity to the ampulla, ultimately resulting in biliary and pancreatic ductal obstruction, the distinction between a primary periampullary duodenal adenocarcinoma and a primary ampullary carcinoma is impossible to make based on imaging alone (Fig. 15). Once again, although these lesions arise in very close anatomic proximity, their biologic behavior tends to be different: dsay et al. [12] reported that duodenal adenocarcinomas were usually less advanced at presentation (i.e., lesser T stage and less likely to harbor lymph node metastases) than ampullary tumors and that patients with duodenal adenocarcinomas typically had better survival rates. enign Causes Distal common bile duct stones There is little argument that CT is not the prima- JR:203, July

4 Raman and Fishman ry diagnostic modality for the identification of stones within either the extrahepatic bile duct or the gallbladder, with both ultrasound and MRI holding clear advantages over CT in both sensitivity and specificity [6]. However, the poor reputation of CT in evaluating biliary stones has almost certainly been exaggerated by a number of early studies based on older technology that were marred by motion artifact, thick-section acquisitions, and poor spatial and contrast resolution [6]. Depending on their internal composition, stones can be visualized to varying degrees on CT: Highly calcified gallstones can usually be fairly easily identified, often with a rim or crescent of surrounding bile, whereas soft-tissue density stones can be more difficult to visualize [20] (Fig. 16). Thus, visualization of cholesterol stones, which are often isodense to surrounding bile, is particularly problematic on CT. Moreover, small stones of soft-tissue density, particularly when impacted at the level of the ampulla, can be almost impossible to identify in some cases [21]. s a result, the radiologist must attempt to carefully examine the distal CD in the setting of biliary obstruction and dilatation, particularly in patients with a known history of cholecystectomy or gallstones. The use of narrow window settings is vital for identifying subtle soft-tissue density stones and the use of multiplanar and curved planar reformations is helpful for tracing the extrahepatic bile duct inferiorly from the liver hilum to the ampulla [21]. Even if a high-density stone is not identified, a sharp cutoff of a dilated CD at the ampulla, often with a wellmarginated meniscus configuration, can hint at the presence of an occult stone [21]. Using these primary and secondary signs of choledocholithiasis, several studies have shown CT sensitivities of more than 80%, including at least one study predating the MDCT era [21 24] (Figs. 17 and 18). Some practices use unenhanced images in the belief that unenhanced imaging might increase the conspicuity of high-density stones in the duct, but there are no data to suggest that dedicated unenhanced images provide any significant benefit in stone detection. lthough not widely used in routine clinical practice, CT examinations performed at higher tube voltage settings (usually 140 kvp) may increase the conspicuity of stones and, in particular, may increase the attenuation and conspicuity of cholesterol stones that are difficult to perceive on standard images [25, 26]. This increased conspicuity of stones at higher tube voltage settings may offer a source of potential clinical utility for dual-energy CT as this technology becomes more widely used in practice. enign biliary strictures The list of different causes of benign biliary strictures is long and extensive, with the most common causes including prior iatrogenic injuries (most often after cholecystectomy and liver transplantation), chronic pancreatitis, and primary sclerosing cholangitis (PSC). Other more rare causes include HIV cholangiopathy, unusual infections (including tuberculosis) (Fig. 19), Mirizzi syndrome, inflammatory strictures from certain chemotherapy drugs and other medications, radiation therapy, portal biliopathy, and sarcoidosis [27 29]. lthough a detailed discussion of each of these entities is beyond the scope of this article, certain entities are important to consider when dealing with obstruction of the distal CD, including chronic pancreatitis, PSC, and strictures related to HIV cholangiopathy [30]. Chronic pancreatitis can be associated with distal bile duct strictures in up to 46% of patients and jaundice in up to 50% [27]. The presence of stigmata of chronic pancreatitis including pancreatic ductal irregularity and beading, parenchymal and ductal calcification, pancreatic pseudocysts, and pancreatic atrophy in the setting of pancreatic and biliary ductal dilatation should strongly raise the possibility of this diagnosis [27]. However, given that patients with chronic pancreatitis are at increased risk of developing pancreatic cancer and the fact that some patients can develop a fibroinflammatory mass at the pancreatic head, the distinction between benign and malignant strictures at this site may not be a simple one [31 33]. PSC very rarely involves the extrahepatic bile duct without abnormalities of the intrahepatic ducts. s a result, when considering this diagnosis in a patient with a CD stricture, it is imperative to closely evaluate the intrahepatic ducts for characteristic features, including beading of the ducts and alternating sites of ductal narrowing and dilatation. Like other types of cholangitis, PSC can be associated with ductal thickening and enhancement, which is usually more diffuse than is commonly seen with malignancy [27] (Fig. 20). However, even in patients with known PSC, abnormal ductal enhancement, thickening, or strictures cannot automatically be assumed to be inflammatory given that the lifetime risk of cholangiocarcinoma in PSC patients may be as high as 10 30% and up to 0.6% per year [34, 35]. ny new stricture on CT regardless of its appearance or apparently benign features must be considered as suspicious and further examined for the presence of malignancy. In particular, CT has proven efficacy in identifying cholangiocarcinoma in the setting of PSC with a sensitivity of 82% and specificity of 80%, which are higher than standard cholangiography [36]. Now increasingly rare given the widespread availability of highly active antiretroviral therapy (HRT), HIV cholangiopathy can result in strictures of both the intrahepatic and extrahepatic ducts and in papillary stenosis. Depending on the exact findings, HIV cholangiopathy can mimic the appearance of an obstructing CD cholangiocarcinoma, ampullary neoplasm, or inflammatory cholangitis such as PSC [27, 30]. Imaging alone cannot reliably differentiate a benign from a malignant biliary stricture, although benign strictures are less likely to produce severe proximal biliary dilatation, are usually associated with a lesser degree of bile duct wall thickening and enhancement at the site of transition, and should not be associated with suspicious locoregional lymphadenopathy or metastatic disease [27]. Moreover, although it can be difficult in many cases, a careful examination of the site of transition in the distal CD should reveal smooth, tapered narrowing rather than an abrupt margin or shouldering [2]. Conclusion In our experience, both the distal CD and the ampulla are common sites of missed diagnoses for radiologists. voiding mistakes in interpreting imaging findings in this location requires a systematic approach especially in the setting of unexplained biliary ductal dilatation. Rather than simply suggesting that MRCP or ERCP be performed for the ultimate diagnosis, radiologists can perform a careful CT evaluation using multiplanar reformations and 3D imaging to determine the correct diagnosis prospectively. timely and correct diagnosis is imperative because lesions in the ampulla and CD can be very aggressive despite their small size. References 1. Sugita R, Furuta, Ito K, Fujita N, Ichinohasama R, Takahashi S. Periampullary tumors: high-spatial-resolution MRI imaging and histopathologic findings in ampullary region specimens. Radiology 2004; 231: Yeh, Liu P, Soto J, Corvera C, Hussain H. MR 20 JR:203, July 2014

5 CT of the Distal CD and mpulla imaging and CT of the biliary tract. RadioGraphics 2009; 29: Pham DT, Hura S, Willmann JK, Nino-Murcia M, Jeffrey R Jr. Evaluation of periampullary pathology with CT volumetric oblique coronal reformations. JR 2009; 193:[web]W202 W Raman SP, Horton K, Fishman E. Multimodality imaging of pancreatic cancer: computed tomography, magnetic resonance imaging, and positron emission tomography. Cancer J 2012; 18: Raman SP, Horton KM, Fishman EK. Transitional cell carcinoma of the upper urinary tract: optimizing image interpretation with 3D reconstructions. bdom Imaging 2012; 37: nderson SW, Zajick D, Lucey C, Soto J. 64-detector row computed tomography: an improved tool for evaluating the biliary and pancreatic ducts? Curr Probl Diagn Radiol 2007; 36: Salles, Nino-Murcia M, Jeffrey R Jr. CT of pancreas: minimum intensity projections. bdom Imaging 2008; 33: Nino-Murcia M, Jeffrey R Jr, eaulieu CF, Li KC, Rubin GD. Multidetector CT of the pancreas and bile duct system: value of curved planar reformations. JR 2001; 176: Wittekind C, Tannapfel. denoma of the papilla and ampulla: premalignant lesions? Langenbecks rch Surg 2001; 386: Lim J. Cholangiocarcinoma: morphologic classification according to growth pattern and imaging findings. JR 2003; 181: Choi Y, Lee J, Lee J, et al. iliary malignancy: value of arterial, pancreatic, and hepatic phase imaging with multidetector-row computed tomography. J Comput ssist Tomogr 2008; 32: dsay V, Ohike N, Tajiri T, et al. mpullary region carcinomas: definition and site specific classification with delineation of four clinicopathologically and prognostically distinct subsets in an analysis of 249 cases. m J Surg Pathol 2012; 36: Kim J, Kim M, Chung J, Lee WJ, Yoo H, Lee JT. Differential diagnosis of periampullary carcinomas at MR imaging. RadioGraphics 2002; 22: Walsh RM, Connelly M, aker M. Imaging for the diagnosis and staging of periampullary carcinomas. 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Eur J Radiol 2010; 75:e74 e Shanbhogue K, Tirumani SH, Prasad SR, Fasih N, McInnes M. enign biliary strictures: a current comprehensive clinical and imaging review. JR 2011; 197:[web]W295 W esa C, Cruz JP, Huete, Cruz F. Portal biliopathy: a multitechnique imaging approach. bdom Imaging 2012; 37: Catalano O, Sahani D, Forcione D, et al. iliary infections: spectrum of imaging findings and management. RadioGraphics 2009; 29: Tonolini M, ianco R. HIV-related/IDS cholangiopathy: pictorial review with emphasis on MRCP findings and differential diagnosis. Clin Imaging 2013; 37: Edge M, Hoteit M, Patel, Wang X, aumgarten D, Cai Q. Clinical significance of main pancreatic ductal dilatation on computed tomography: single and double duct dilatation. World J Gastroenterol 2007; 13: Menges M, Lerch MM, Zeitz M. The double duct sign in patients with malignant and benign pancreatic lesions. Gastrointest Endosc 2000; 52: Schlosser W, Siech M, Gorich J, eger HG. Common bile duct stenosis in complicated chronic pancreatitis. Scand J Gastroenterol 2001; 36: Morris-Stiff G, hati C, Olliff S, et al. Cholangiocarcinoma complicating primary sclerosing cholangitis: a 24-year experience. Dig Surg 2008; 25: Schulick RD. Primary sclerosing cholangitis: detection of cancer in strictures. J Gastrointest Surg 2008; 12: Campbell WL, Peterson MS, Federle MP, et al. Using CT and cholangiography to diagnose biliary tract carcinoma complicating primary sclerosing cholangitis. JR 2001; 177: (Figures start on next page) JR:203, July

6 Raman and Fishman Fig year-old man with ampullary mass found at upper endoscopy performed for symptoms of indigestion and reflux. and, Coronal multiplanar reformation () and volume-rendered () CT images show discrete mass at ampulla (arrow, ) and only minimal biliary ductal dilatation (). Mass was ultimately found to be ampullary adenoma. Fig year-old woman with ampullary mass found at endoscopy performed for sensation of chest fullness. and, Coronal multiplanar reformation () and coronal volume-rendered () CT images show polyploid mass (arrows) in periampullary duodenum and no visible ductal dilatation. Mass was found to be ampullary adenoma. 22 JR:203, July 2014

7 CT of the Distal CD and mpulla Fig year-old woman who presented with 1-year history of recurrent jaundice. and, Coronal volume-rendered CT images show abrupt irregular narrowing and beaking of distal common bile duct (CD) with irregular enhancement (arrows). This case was found to be distal CD cholangiocarcinoma. Fig year-old man who presented with elevated liver enzyme values and bilirubin level during routine office visit. Coronal multiplanar reformation CT image shows focal soft tissue (arrow) obstructing mid common bile duct with proximal biliary dilatation and abrupt margin at site of transition. This case was found to be cholangiocarcinoma. Fig year-old man who presented with elevated liver function test values and abdominal pain. Coronal multiplanar reformation CT image shows diffuse enhancement and wall thickening (arrow) of common bile duct. Intrahepatic ducts (not shown) were not involved. lthough inflammatory or infectious cholangitis was considered, this case was found to be cholangiocarcinoma. JR:203, July

8 Raman and Fishman Fig year-old woman who presented with weight loss, jaundice, and abdominal pain. Coronal volume-rendered CT image shows markedly dilated intrahepatic and extrahepatic ducts and abrupt beaking (arrow) and narrowing of distal common bile duct. lthough no discrete mass was visualized on CT, small ampullary carcinoma was found at endoscopic ultrasound. Fig year-old man who presented with painless jaundice. Coronal multiplanar reformation CT image shows polyploid mass (arrow) at ampulla obstructing both pancreatic duct and common bile duct. This mass was found to be ampullary carcinoma. Fig year-old man who presented with jaundice and pruritus. and, Coronal volume-rendered () and multiplanar reformation () CT images. Despite presence of stent and poor duodenal distention, images show focal medial duodenal wall thickening (arrows) at level of ampulla, which was ultimately found to be ampullary carcinoma. 24 JR:203, July 2014

9 CT of the Distal CD and mpulla Fig year-old woman who presented with jaundice and abdominal pain. Coronal volume-rendered CT image shows focal wall thickening (arrows) along medial duodenal wall at level of ampulla, which was ultimately found to be ampullary carcinoma. Fig year-old man who presented with jaundice. Coronal volumerendered CT image shows focal mass (arrow) at ampulla obstructing distal common bile duct (CD). Distal CD is abruptly narrowed and irregular. This mass was ultimately found to be ampullary carcinoma. Fig year-old woman with incidentally discovered biliary dilatation on unenhanced CT performed to exclude renal stones. and, xial () and coronal () arterial phase multiplanar reformation images show hypervascular mass (white arrows) obstructing distal common bile duct and pancreatic ducts and adjacent hypervascular lymph node metastasis (black arrow, ). Mass was found to be ampullary carcinoid. JR:203, July

10 Raman and Fishman Fig year-old man who presented with jaundice. and, Coronal multiplanar reformation (MPR) () and volume-rendered () CT images show abrupt obstruction of common bile duct by hypodense mass in pancreatic head (arrows). C, Coronal MPR image shows concurrent severe obstruction of pancreatic duct. Mass was found to be pancreatic adenocarcinoma. Fig year-old woman who presented with painless jaundice. Coronal minimum-intensityprojection CT image shows markedly dilated common bile duct with abrupt narrowing near ampulla. Morphology of ductal narrowing raised concern even though no discrete mass was identified; this case was found to be small pancreatic adenocarcinoma obstructing duct. Fig year-old man who presented with jaundice and abdominal pain. Coronal volumerendered CT image shows markedly dilated common bile duct with abrupt irregular narrowing distally. Subtle texture change in pancreatic head is seen but no discrete mass. This case was found to be small pancreatic adenocarcinoma. Fig year-old man with duodenal mass discovered during upper endoscopy performed for upper gastrointestinal bleeding. Coronal multiplanar reformation CT image shows annular constricting mass (arrows) that extends into ampulla. This mass was judged after surgical resection to be periampullary duodenal adenocarcinoma. C 26 JR:203, July 2014

11 CT of the Distal CD and mpulla Fig year-old man with known cholelithiasis on prior ultrasound. xial CT image shows softtissue density stone (arrow) in distal common bile duct and ampulla with characteristic rim of surrounding bile. Fig year-old man with history of gallstones. Coronal volume-rendered CT image shows obstructing stone (arrow) in distal common bile duct and proximal biliary dilatation. Fig year-old woman who presented with fever and jaundice. Coronal volume-rendered CT image shows focal thickening of distal common bile duct (arrows) initially thought to be either pancreatic cancer or ampullary carcinoma. This case was ultimately found to be tuberculosis, and there were multiple other sites of infection elsewhere in body. Fig year-old woman with choledocholithiasis incidentally discovered during evaluation for melanoma. Coronal volume-rendered CT image shows common bile duct stone (arrow) without significant proximal biliary dilatation. JR:203, July

12 Raman and Fishman Fig year-old man with known primary sclerosing cholangitis. and, xial () and coronal () CT images show thickening and enhancement of right hepatic duct (arrow, ) and common bile duct (arrow, ); these findings are suggestive of active bile duct inflammation. FOR YOUR INFORMTION This article is available for CME and Self-ssessment (S-CME) credit that satisfies Part II requirements for maintenance of certification (MOC). To access the examination for this article, follow the prompts associated with the online version of the article. 28 JR:203, July 2014