Radiological Spectrum of Intraductal Papillary Tumors of the Bile Ducts

Papillary tumor of the bile duct is characterized by the presence of an intraductal tumor with a papillary surface comprising innumerable frondlike infoldings of proliferated columnar epithelial cells surrounding slender fibrovascular stalks. There may be multiple tumors along the bile ducts (papillomatosis or papillary carcinomatosis), which are dilated due to obstruction by a tumor per se, by sloughed tumor debris, or by excessive mucin. Radiologically, the biliary tree is diffusely dilated, either in a lobar or segmental fashion, or aneurysmally, depending on the location of the tumor, the debris, and the amount of mucin production. A tumor can be depicted by imaging as an intraductal mass with a thickened and irregular bile duct wall. Sloughed tumor debris and mucin plugs should be differentiated from bile duct stones. Cystically or aneurysmally, dilated bile ducts in mucin-hypersecreting variants (intraductal papillary mucinous tumors) should be differentiated from cystadenoma, cystadenocarcinoma and liver abscess.

Recurrent Pyogenic Cholangitis: Clinico-Pathologic Correlation of Focal Attenuation Differences on Multi-Phasic Spiral CT

PURPOSE: To determine the clinical and the pathologic significance of the focal attenuation differences (FAD) and bile duct wall enhancement occurring in recurrent pyogenic cholangitis (RPC) and seen at multiphasic spiral CT. MATERIALS AND METHODS: Among the multiphasic (non-contrast, arterial and portal or delayed phase) spiral CT findings of 60 consecutive patients, two types of FAD were noted during the non-contrast phase. These were Type A (iso) and Type B (low attenuation), and their distribution pattern (lobar versus patchy, multifocal) and the and the presence or absence of bile duct wall enhancement were recorded. The radiologic findings were correlated with the clinical and pathologic findings. RESULTS: Two types of FAD were noted in 40 of the 60 patients. Active in flammation was present in 19 of the 27 with Type-A and in ten of the 15 in whom the presence of RPC was pathologically proven. Ten of the 13 with Type-B FAD were in a subclinical state, and nine of the ten in whom RPC was pathologically proven had chronic inflammation. Among 20 patients who did not have FAD, RPC was subclinical in 18 and dormant in nine of the eleven in whom its presence was pathologically proven (p<0.001). Clinico-pathologic correlation with bile duct wall enhancement and the distribution pattern of FAD showed no statistical significance. CONCLUSION: The inflammatory activity of RPC can be predicted by analysis of the FAD seen at multiphasic spiral CT.

Vascular Invasion of Klatskin Tumor: Computed Tomography vs Digital Subtraction Angiography in Determining Resectability

PURPOSE: To compare the accuracy of computed tomography (CT) with that of digital subtraction angiography (DSA) in predicting the resectability of Klatskin tumor on the basis of vascular invasion. MATERIALS AND METHODS: Twenty-five patients with Klatskin tumor who had undergone laparotomy were in-cluded in this study. In order to assess the surgical resectability of their tumors, the preoperative CT scans and DSA of these patients were retrospectively assessed in terms of vascular invasion. The criteria of unresectability were tumoral invasion of the proper hepatic artery or main portal vein, or simultaneous invasion of the hepatic artery on one side and the other side portal vein. RESULTS: Tumors were unresectable in 13 cases, and resectable in 12. CT and DSA predicted nine and three tumors as unresectable ones, respectively. The sensitivity, specificity, positive predictive value, negative predic-tive value and accuracy of CT in determining whether a tumor was unresectable were 61.5 %, 91.7%, 88.9 %, 6 8 .8 % and 76.0 %, respectively. For DSA, the respective figures were 23.1 %, 100 %, 100 %, 54.5 % and 6 0 .0 %. For the detection of vascular invasion without diameter change, CT was superior to DSA; for the evaluation of vascular anatomy, it was, however, less effective. CT failed to detect small hepatic metastasis (n=2), lymph node metastasis (n=1), variation of the bile duct (n=1), and the distal extent of tumor in the bile duct (n=1), factors which precluded surgical resection. CONCLUSION: CT is a reliable method for the detection of vascular invasion and tumor unresectability. For the detection of vascular anatomic variation, the combined use of CT and DSA would be helpful.

Intrahepatic Cholangiocarcinoma: Gross Appearance and Corresponding Pathologic and Radiologic Features

PURPOSE: To assess the clinical and pathologic features of each type of intrahepatic cholangiocarcinoma,which is divided into three types according to gross appearance, and to determine the efficacy of CT in detectingthis tumor. MATERIALS AND METHODS: The pathologic and CT features of 53 surgically proven cases of intrahepaticcholangio-carcinoma were reviewed. On the basis of their gross appearance, the tumors were divided into threetypes, as follows: mass forming (n=33), periductal infiltrating (n=6), and intraductal growth type (n=14). CTscans were analyzed for sensitivity of detection and correlation between a tumors appearance and itshistopathology. RESULTS: The most common histopathologic feature of mass forming and periductal infiltrating typewas tubu-lar adenocarcinoma, while in the intraductal growth type, papillary adenocarcinoma (100%) was common.With regard to pattern of tumor spread, intrahepatic and lymph node metastasis were more common in the massforming and periductal infiltrating type than in the intraductal growth type. CT findings including intra-hepaticmass, ductal wall thickening or intraductal mass associated with segmental dilatation of intrahepataic bile ducts,corresponded with these morphologic types. CONCLUSION: This classification according to gross appearance is ofconsiderable value when interpreting the pathologic features of intrahepatic cholangiocarcinoma. CT seems to be auseful modality for the detection of tumors and may be consistent with their gross morphologic findings.

Bile Duct Dilatation after Subtotal Gastrectomy in Stomach Cancer: Comparison with Gastroduodenostmy (BillothI) and Gastro Jejunosto my (Billoth II)

PURPOSE: To evaluate the incidence and degree of bile duct dilatation after partial gastrectomy due togastric cancer and to determine any differences between gastroduodenostomy (Billoth I) and gastrojejunostomy(Billoth II). MATERIALS AND METHODS: We retrospectively analyzed the follow up abdominal CT findings in 113patients who had undergone partial gastrectomy without truncal vagotomy or cholecystectomy. In all cases,preoperative abdminal CT findings showed no evidence of bile duct dilatation. Among 113 patients, 41 underwentBilloth I surgery, and 72 underwent Billoth II. No case showed clinical or radiological evidence of obstructivecauses of bile duct dilatation. Among these patients, we decided the criteria for dilatation when this was noted.The grade was either mild (3 -4 mm), moderate (5 -8mm), or severe (over 9mm), as measured at the centralintra-hepatic duct. Extra-hepatic duct dilatation was graded as mild (6 -8mm), moderate (9 -12mm) or severe (over13 mm). We analyzed serum bilrirubin and alkaline phosphatase levels. RESULTS: When the central intrahepatic ductwas measured, 78 of 113 patients(69 %) showed bile duct dilata-tion; 24 of 41 cases(58.5 %) were in the billoth Igroup and 54 of 72 (75 %) were the in Billoth II group. After measurement of the extra hepatic duct, 22 of41cases(53.6%) in the Billoth I group and 54 of 72 (75 %) in the Billoth II group were found to be dilated. Theresults showed a slightly increased incidence of bile duct dilatation in the Billoth, II group but this was notstatistically significant(p>0.05). In the laboratory, total, direct, and indirect bilirubin, as well as alkalinephosphatase levels, were measured. Higher levels were found in Billoth II than in Billoth I but all findings werewithin normal limits. CONCLUSION: Mild dilatation of the bile duct after partial gastrectomy was a not uncommonfinding, and there was no significant difference of incidence or degree of dilatation according to the procedureperformed. If a patient has no clinical symptoms, it appears that clinical it appears that clinical evaluationdoes not require fur-ther study.

CT Findings of Intrahepatic Cholangiocarcinoma Associated with Hepatolithiasis

PURPOSE: To assess the CT findings of intrahepatic cholangiocarcinoma associated with hepatolithiasis. MATERIALS AND METHODS: The CT features of 26 patients with cholangiocarcinoma and hepatolithiasis were reviewed and compared with those of 23 patients with intrahepatic stones alone, acting as control subjects. CT findings were analyzed for tumor appearance and adjacency to hepatolithiasis. We studied clinical findings, noting the presence or absence of wall thickening or soft tissue attenuation within the bile duct, the luminal diameter of dilated bile duct, and the presence of periductal enhancement, and compared these with the findings for control groups. RESULTS: CT images of the tumor revealed a hepatic low-attenuating mass with peripheral rim enhancement(n=14, 54 %), or periductal thickening, or low-attenuating lesions in segmental dilatation of intrahepataic bile ducts(n=12, 46%). Most hepatic tumors were seen in areas adjacent to hepatolithiasis, or in a bile duct. Compared with control groups, patients with cholangiocarcinoma were old (p0.05). CONCLUSION: When an intrahepatic low-attenuating mass, or peridutal thickening and low-attenuating lesions in segmental dilated intrahepatic duct are found associated in adjacent intrahepatic stones, intrahepatic cholangiocarcinoma should be considered.

Prominent Papilla of Vater at CT: Differentiation between Benign and Malignant Lesion

PURPOSE: To establish the criteria for differential diagnosis between malignant tumor and benign prominenceof papilla of Vater, as seen on CT. METHOD AND MATERIALS: Sixteen consecutive patients with prominent papilla ofVater, as seen on CT during a ten-month period were includedin this study. Final diagnosis was papilla of Vatercancer (n=5), chronic inflammation (n =3), benign tumor (n=3), or and normal (n=5), and this was confirmed bysurgery in 11 cases, and endoscopy in five. Papilla size and attenuation, the presence of accompanied dilatationof the bile or pancreatic duct, and lymph node enlargement were analyzed by two experienced radiologists, whoreached a conensus. A past history of stone disease, laboratory findings such as serum bilirubin, serum alkalinephosphatase, or endoscopic findings of duodenal diverticulum were additionally analyzed. RESULT: Papilla size wasthe only significantly different CT finding between malignant and benign lesions, and serum alkaline phosphataselevels were also significantly different between the two groups. The smallest malignant tumor was 18 mm and thelargest benign lesion was 15 mm. The presence of bile or pancreatic duct dilatation, serum bilirubin level,attenuation of the mass, a history of stone disease, and lymph node enlargement were not significantly differentbetween the two groups. CONCLUSION: In patients with prominent papilla of Vater, as seen on CT, a mass largerthan 18 mm is the only reliable radiologic finding to indicate malignant tumor of papilla of Vater. Serum alkalinephosphatase levels can, in addition, be helpful for the differential diagnosis of benign and malignant lesions.

Thin Section Helical CT Findings of Klatskin Tumor and Benign Stricture: Cholangiographic Correlation

PURPOSE: The purpose of this study was 1) to describe the thin section helical CT findings of hilar cholangiocarcinoma and of benign stricture, and to discuss the differential points between the two disease entities and 2) using cholangiographic correlation, to evaluate the diagnostic accuracy of helical CT in determining the extent of hilar cholangiocarcinoma. MATERIALS AND METHODS: Twenty-seven patients with hilar cholangiocarcinoma and eight with benign biliary dilatation were studied. All except four with hilar cholangiocarcinoma, who underwent CT using a conventional scanner, were studied with two-phase helical CT. In all patients, cholangiographs were obtained by digital fluoroscopy after the injection of contrast materials into PTBD catheters. The level of obstruction was classified according to Bismuth, and 35 CT scans were studied blindly and retrospectively by two radiologists. The findings were analyzed for the presence of tumor, and then divided into two groups (cholangiocarcinomas and benign strictures), and the positive predictive value was calculated. The CT images of klatskin tumor were analyzed with special emphasis on the level and shape of the hilar obstruction. The level of biliary obstruction and extent of the tumor were carefully correlated with the results of cholangiography. RESULTS: Thin-section spiral CT correctly identified all tumor mass as a focal wall thickening obliterating the lumen. On arterial/portal phase CT scanning, 81% of infilterative tumors showed high attenuation. In all patients, differentiation between benign stricture and klatskin tumor was possible ; correct identification of the level of obstruction and extent of tumor, according to Bismuth's classification, was possible in 63% of cases. CONCLUSION: For correct diagnosis of hilar cholangiocarcinoma and differentiation of benign stricture, helical CT was highly accurate and effective. Because of limital Z-axis resolution, however, the exact intraductalextent of the tumor was less accorately diagnosed.

PTBD Spiral CT Cholangiography: Utility in Patients with Extrahepatic Biliary Obstruction

PURPOSE: The purpose of this study is to assess the utility of PTBD spiral CT cholangiography, after infusion of contrast media through a PTBD tube, for evaluation of a biliary lesion after emergency PTBD due to severe jaundice. MATERIALS AND METHODS: Forty patients with emergency PTBD due to extrahepatic biliary obstruction were transferred to our clinic and prospectively studied. The causes of obstruction were 17 extrahepatic cholangiocarcinomas (including three Klatskin's tumors), seven pancreatic head carcinomas, six calculous diseases of the common bile duct, six periampullary lesions, two ampulla of Vater carcinomas, one gall bladder carcinoma with invasion of the common hepatic duct, and one cholangitis. Diagnosis was on the basis of pathologic, radiologic, and clinical findings. Pre-contrast CT scanning was performed. After the infusion of contrast media (iothalamate : normal saline=1:10) through a PTBD tube, spiral CT scans were obtained. After IV infusion of contrast media (Ultravist, 100cc), early- and delayed-phase spiral CT scans were obtained at 45 and 210 seconds, respectively, with an interscan interval of 5mm. 3-D CT cholangiograms were then reconstituted. Spiral CT without infusion of contrast media through a PTBD tube and PTBD spiral CT cholangiography were performed in 14 cases. The level of extrahepatic biliary obstruction was categorized as either upper, middle, or lower third. In 21 surgically confirmed cases, we evaluated the accuracy with which the level and cause of obstruction was determined; levels and causes during surgery and by as seen on PTBD cholaniography were compared. RESULTS: The levels of obstruction diagnosed on PTBD spiral CT cholangiography and on 3-D CT cholangiography corresponded in all cases to the levels during surgery and on PTBD cholangiography [upper third (n=7), middle third (n=12), lower third (n=21)], and the level diagnosed on spiral CT without infusion of contrast media through a PTBD tube corresponded to the level during surgery in ten of 14 cases. The cause of obstruction diagnosed on PTBD spiral CT cholangiography corresponded to pathologic findings in 19 of 21 cases. In 15 cases, 3-D CT cholangiography was diagnostically helpful. CONCLUSION: PTBD spiral CT cholangiography is a useful diagnostic method for determining the level and cause of biliary obstruction.

CT Findings of Malignancies Occurring in Choledochal Cysts: Differential Points with Benign Inflammations

PURPOSE: To demonstrate CT findings of malignancies occurring in choledochal cysts focusing on the differential points with benign inflammation. MATERIALS AND METHODS: The CT findings of seven patients with malignancies occurring in choledochal cysts(six cholangiocarcinomas and one cholangiohepatoma) and three with benign inflammatory wall thickening were reviewed. Six were studied with two-phase(arterial and portal) CT(threethe malignancies and all benign inflammations) and the remainder with conventional CT in the late portal or equilibrium phase. Spiral dynamic CT scans were performed in all two phase CT, except in the case of onemalignancy. The study was focused on the shape and enhancement pattern of the lesions and the presence of localinvasion or distant metastasis. RESULTS: Three of seven associated malignancies showed concentric wall thickening(mean wall thickness=11.3mm), two eccentric, wall thickening and two polypoid masses. Two of three arterial phase CT scans showed tumor enhancement and one showed low attenuating concentric wall thickening, well delineated from a strongly enhanced pancreas. In portal or delayed phase CT scans, all masses were isodense orslightly hypodense compared with the liver or pancreas. Extensive regional lymphadenopathy or distant metastasis was present in six patients at the time of diagnosis. Three cases of benign inflammatory wall thickening showed athinner wall(mean thickness=5mm), and two showed arterial enhancement of the inner wall with only, a diffuse and even pattern. On preoperative CT diagnosis, two cases of benign inflammatory wall thickening were misdiagnosed as malignancies. CONCLUSION: Concentric wall thickening type was the most difficult to differentiate from benign wall thickening. Irregular wall thickening of more than 10mm and enhancement of the whole thickeness of the wall is a reliable sign of malignancy. Dynamic spiral CT is essential for this evaluation.