MR imaging of intrahepatic cholangiocarcinoma with pathologic correlation

OBJECTIVE: The objective of this study was to determine the MR imaging features of intrahepatic cholangiocarcinoma. MATERIALS AND METHODS: MR images of 50 patients with pathologically proven intrahepatic cholangiocarcinoma were reviewed retrospectively. T1- and T2-weighted spin-echo images were obtained in all patients. Contrast-enhanced T1-weighted imaging was performed in 25 patients. Signal intensity and enhancement pattern of the tumors were correlated with pathology findings. The frequency of central hypointense regions on T2-weighted images and the intrahepatic bile duct dilatation of several other hepatic tumor types were investigated. Results were compared with imaging results of cholangiocarcinoma. RESULTS: On T2-weighted images, central hypo- and hyperintense regions were detected in tumors in 27 and 17 patients, respectively. Contrast-enhanced T1-weighted imaging revealed central hypointense areas exhibiting homogeneous, heterogeneous, and no enhancement in six, three, and five, respectively, of 14 patients. Regions of fibrosis displayed enhancement, whereas those of coagulative necrosis showed no enhancement. The signal intensity difference on T2-weighted images between the center and the edge of the tumor correlated well with the fibrotic ratio difference between those two areas corresponding to the MR image (Spearman's rank correlation test, r = 0.72, 95% confidence interval = 0.48-0.86). T2-weighted images revealed central hypointense regions in 16 of 34 instances of hepatic colorectal metastases. However, hypointensity was observed in only 26 of 234 other hepatic tumors. Intrahepatic bile duct dilatation was evident in 27 of 50 cases of cholangiocarcinoma but occurred in only a single case of 34 instances of hepatic colorectal metastases. CONCLUSION: The combination of the signal intensity on T2-weighted images and the enhancement pattern on contrast-enhanced T1-weighted images showed good correlation with the pathologic findings of cholangiocarcinoma. The occurrence of a central hypointense area on T2-weighted images is not pathognomonic; however, this finding, which reflects severe fibrosis, appears to be a characteristic marker of intrahepatic cholangiocarcinoma. The presence of intrahepatic bile duct dilatation may indicate cholangiocarcinoma, although it is difficult to differentiate cholangiocarcinoma from hepatic colorectal metastasis.     

Role of MR cholangiopancreatography in patients with failed or inadequate ERCP

OBJECTIVE: The purpose of this study was to evaluate the spectrum of MR imaging features of primary sclerosing cholangitis. MATERIALS AND METHODS: A retrospective review was performed of MR imaging findings including MR cholangiography and multiphasic contrast-enhanced dynamic sequences in 22 patients with primary sclerosing cholangitis. MR imaging analysis included abnormalities of intra- and extrahepatic bile ducts, abnormalities of liver parenchyma, changes in liver morphology, and lymphadenopathy. RESULTS: Abnormal findings of bile ducts were seen in all 22 patients; the most common finding was intrahepatic bile duct dilatation (77%), followed by intrahepatic bile duct stenosis (64%), extrahepatic bile duct wall enhancement (67%), extrahepatic bile duct wall thickening (50%), extrahepatic bile duct stenosis (50%), and intrahepatic bile duct beading (36%). Increased enhancement of the liver parenchyma on dynamic arterial-phase images, predominantly in the peripheral areas of the liver, was identified in 56% of patients. Other findings included periportal lymphadenopathy (77%), periportal high signal intensity on T2-weighted images (68%), hypertrophy of the caudate lobe (68%), and abnormal hyperintensity of the liver parenchyma on T1-weighted images (23%). CONCLUSION: On MR imaging, primary sclerosing cholangitis showed several characteristic features, including bile duct abnormalities and increased enhancement of the liver parenchyma. MR cholangiography and contrast-enhanced dynamic MR techniques are useful for revealing intra- and extrahepatic signs of primary sclerosing cholangitis.     

Primary biliary cirrhosis: evaluation with T2-weighted MR imaging and MR cholangiopancreatography

Purpose

The aim of this retrospective study is to evaluate the role of T2-weighted MR imaging (MRI) and MR cholangiopancreatography (MRCP) findings in the diagnosis of primary biliary cirrhosis (PBC).

Materials and methods

The following T2-weighted MRI and MRCP findings: segmental hepatic atrophy/hypertrophy, irregular liver surface, parenchymal lace-like fibrosis, rounded low signal intensity lesions centering portal vein branches (periportal halo sign), periportal hyperintensity (cuffing), splenomegaly, ascites, lymphadenopathy, venous collaterals, and the configuration of intrahepatic biliary ducts were reviewed for their diagnostic significance by two observers in 13 female patients (mean age: 49 years) with PBC. Discordant readings of the observers were resolved at consensus.

Results

When parenchymal lace-like fibrosis and periportal halo sign were seen together the sensitivity of T2-weighted MR images was 69%. In six cases periportal hyperintensity (cuffing) and periportal halo sign were seen together. Segmental hypertrophy was present in nine patients and hepatic surface irregularity due to regenerative nodules were present in 10 patients. Lymphadenopathy was seen in 10, splenomegaly was seen in 5, collateral vascular structures were seen in 2 and minimal perihepatic free fluid was seen in 2 patients. MRCP images revealed various mild irregularity in the intrahepatic bile ducts in 8 patients and focal narrowing at the common bile duct level in 1 patient.

Conclusion

MRI and MRCP may support the clinical and laboratory findings of PBC even in the early stages of the disease. MRI can also be a choice of method for the recommended prolonged follow up.     

Tuberculosis of the pancreas: MRI features

OBJECTIVE: The purpose of this study was to describe the MRI features of tuberculosis of the pancreas. CONCLUSION: Pancreatic tuberculosis can be focal or diffuse. If focal, it presents as a sharply delineated mass located in the pancreatic head, showing heterogeneous enhancement. Lesions are hypointense on fat-suppressed T1-weighted images and a mixture of hypo- and hyperintense on T2-weighted images. The appearances of common bile duct and main pancreatic duct are normal. Diffuse involvement is characterized by pancreatic enlargement with narrowing of the main pancreatic duct and heterogeneous enhancement. Signal intensity abnormalities indicating diffuse involvement include hypointensity on fat-suppressed T1-weighted images and hyperintensity on T2-weighted images.     

Computed tomographic diagnosis of obstructive jaundice in the absence of intrahepatic ductal dilatation.

Six patients with obstructive jaundice had computed tomography (CT) scans showing a dilated extrahepatic biliary tree in the absence of intrahepatic ductal dilatation. Dilated extrahepatic bile ducts were most easily identified by means of intravenous injection of urographic contrast material, which permitted them to be seen as low density structures. Findings in these patients emphasize that (1) demonstration of dilated intrahepatic bile ducts is not a prerequisite for the CT diagnosis of obstructive jaundice and (2) careful CT evaluation of the extrahepatic biliary tree is necessary to identify patients with isolated dilatation of the common hepatic or common bile duct.     

MR Imaging Findings of Clonorchiasis

Objective

The purpose of this study was to evaluate the MR spectrum and MR cholangiographic imaging findings of clonorchiasis.

Materials and Methods

We reviewed 26 patients with confirmed clonorchiasis by either stool tests (n=24) or surgery (n=2). MR imaging was performed on a 1.5 T system (GE Medical Systems, Milwaukee, WI) with a torso coil. Axial T1- and T2-weighted, gadolinium-enhanced dynamic images and MR cholangiography were obtained. Image analyses were used to identify abnormalities of the intrahepatic and extrahepatic bile ducts and the presence of hepatobiliary malignancy. All MR examinations were reviewed by the consensus of two abdominal radiologists.

Results

Intrahepatic bile duct abnormalities were seen in 23 (89%) of the 26 patients. The most common finding was mild dilatation of the intrahepatic bile duct which was found in 21 (81%). "Too many intrahepatic ducts" were found in 16(62%), wall enhancement and thickening in 21 (81%) and filling defects and ductal stricture in the intrahepatic bile duct in 6 (24%) and 3 (12%) patients, respectively. Extrahepatic ductal dilation was found in 5 (19%) and 9 (35%) revealed hepatobiliary malignancy.

Conclusion

MR imaging revealed various findings of clonorchiasis, including dilatation, wall enhancement, stricture of the intrahepatic ducts and filling defect within the intrahepatic bile duct.     

Oriental cholangiohepatitis: pathologic, clinical, and radiologic features

Oriental cholangiohepatitis, an endemic disease in Southeast Asia, is characterized by recurrent attacks of abdominal pain, fever, and jaundice. Pathologically, the intra- and extrahepatic ducts are dilated and contain soft, pigmented stone and pus. There is proliferation of bile ducts and infiltration of inflammatory cells along the periportal spaces and hepatic parenchyma. Localized intrahepatic segmental ductal stenosis may be present, especially in the lateral segment of the left lobe or posterior segment of the right hepatic lobe. The cause of the disease is not known, but associations with clonorchiasis, ascariasis, and nutritional deficiency have been suggested. Sonographic and CT findings include intra- or extrahepatic duct stones, dilatation of the extrahepatic duct with relatively mild or no dilatation of the intrahepatic ducts, localized dilatation of the lobar or segmental bile ducts, increased periportal echogenicity, segmental hepatic atrophy, and gallstones. Cholangiographic findings include bile duct stones; disproportionately severe dilatation of the extrahepatic ducts with mild or no dilatation of the intrahepatic ducts; and focal strictures, acute peripheral tapering, straightening, rigidity, decreased arborization, and an increased branching angle of the intrahepatic bile ducts.     

Intrahepatic periportal abnormal intensity on MR images: an indication of various hepatobiliary diseases

The frequency and degree of intrahepatic periportal abnormal intensity (PAI) on magnetic resonance images in patients with or without various hepatobiliary and pancreatic diseases were analyzed. In 63 patients without hepatobiliary disease, except for a small metastatic liver tumor or cavernous hemangioma, no definite PAI was seen. Definite PAI was seen in all patients with obstructive jaundice, cholangitis, and cholangiocellular carcinoma. It was also clearly seen in all four cases of malignant lymphadenopathy in the hepatoduodenal ligament, in one of two cases of acute hepatitis, and in four of 47 cases of liver cirrhosis. However, in patients with bile duct dilatation or with gallstone or pancreatic disease without obstructive jaundice or cholangitis, no definite PAI was seen. Histologic studies of the liver performed in 23 patients with definite PAI showed edema, ductular proliferation, dilatation of lymph vessels, and inflammatory cell infiltration in portal tracts. It is concluded that definite intrahepatic PAI is a useful sign that indicates the presence of biliary or diffuse hepatic disease.     

Ampullary carcinoma: Demonstration by current MR techniques

The objective of this study was to demonstrate the appearance of ampullary carcinoma using current MR techniques, including fat suppression, gadolinium enhancement, and MR cholangiography. Nine patients with ampullary carcinoma were examined by MRI at 1.5 T. MR examinations included T1-weighted spoiled gradient echo, T1-weighted fat-suppressed, and immediate postgadolinium spoiled gradient echo images for all patients and MR cholangiography for three patients. The imaging features of ampullary carcinomas, including tumor size and morphology, signal intensity, and enhancement characteristics, were determined. Ampullary carcinomas shown on MR images ranged in size from 1.5 to 5.5 cm. Tumors were low in signal intensity on precontrast T1-weighted spoiled gradient echo and T1-weighted fat-suppressed images relative to normal pancreatic tissue and enhanced less than normal pancreas on immediate postgadolinium spoiled gradient echo images. Tumor conspicuity was greatest on immediate postgadolinium spoiled gradient echo images. MR cholangiography demonstrated high grade obstruction of the common bile duct and mild dilatation of the pancreatic duct at the level of the ampulla with abrupt termination of the ducts in two untreated patients and moderate dilatation of the common bile duct in one patient who had a biliary stent. Ampullary carcinomas can be demonstrated on MR images as small masses arising at the ampulla. Tumors are well defined on immediate postgadolinium spoiled gradient echo images.     

胆管下端梗阻性黄疸性疾病的64层螺旋CT表现

目的:探讨胆管下端梗阻性黄疸性疾病的64层螺旋CT表现和诊断价值。方法:回顾性分析2008年9月～2009年9月间84例胆总管下端梗阻患者的临床及影像资料,按良性和恶性分为两组:良胜组32例,包括单纯结石组21例和胆管炎11例(其中6例并发结石)。恶性组52例,其中胆管下段癌11例,壶腹部癌11例,胰头癌30例。所有病例均行CT平扫、动脉期及静脉期扫描,图像后处理采用MIP、MinIP、MPR、CPR等。CT观察指标包括:定量指标:胆总管内径、肝内I级胆管内径、胆总管壁厚度、梗阻部位距肝门部长度;定性指标:肿块有无、形态以及强化程度、肝内I级以远胆管扩张程度、范围、管壁强化程度、有无结石、有无双管征等。结果:所有病例均清晰显示。梗阻部位距离肝门部长度良、恶性组间差别明显(P0.01);而恶性组中胆管下段癌和胰头癌分别与壶腹部癌之间也有统计学差异(P0.05),其他指标各组间差别无显著性(P0.05)。结论:多层螺旋CT扫描及其重建方法能够清楚地显示胆管下端梗阻性黄疸性疾病,并有助于进行诊断和鉴别诊断。     

Biliary atresia in neonates and infants: triangular area of high signal intensity in the porta hepatis at T2-weighted MR cholangiography with US and histopathologic correlation

PURPOSE: To correlate a triangular area of high signal intensity in the porta hepatis on T2-weighted magnetic resonance (MR) cholangiograms of biliary atresia with ultrasonographic (US) and histopathologic findings in a portal mass observed during a Kasai procedure. MATERIALS AND METHODS: Twenty-one consecutive neonates and infants (age range, 13-88 days; mean age, 59 days) with cholestasis underwent US and single-shot MR cholangiography. In 12 patients with biliary atresia diagnosed at histopathologic examination, MR cholangiographic findings in the porta hepatis were correlated with US and histopathologic findings in the portal mass. RESULTS: At US, eight of the 12 patients had round, linear, or tubular hypoechoic portions within a triangular cord; MR cholangiography revealed a triangular area of high signal intensity confined to the porta hepatis. Histopathologic examination of the portal mass revealed a cystic or cleftlike lesion surrounded by loose myxoid mesenchyme and platelike fetal bile ducts. Neither the large cystic lesion without ductal epithelium nor the small cleftlike lesion with scanty epithelium demonstrated bile staining. Similar areas of high signal intensity were not seen on T2-weighted images in the remaining patients (four with biliary atresia and nine with neonatal hepatitis). CONCLUSION: In biliary atresia, T2-weighted single-shot MR cholangiography can show a triangular area of high signal intensity in the porta hepatis that may represent cystic dilatation of the fetal bile duct.     

Mangafodipir trisodium: effects on T2- and T1-weighted MR cholangiography

The purpose of this study was to determine the effects of mangafodipir trisodium on heavily T2-weighted magnetic resonance cholangiography (MRC) images and on functional T1-weighted MRC. Pre- and post-mangafodipir trisodium heavily T2-weighted MRC and fat-suppressed T1-weighted three-dimensional (3D) gradient-echo MRC images were obtained in a patient with a prior cholecystectomy and a long cystic duct remnant that had apparent biliary stasis. Multiplanar reconstructed images were created. The precontrast T2-weighted MRC showed a long cystic duct remnant and a normal common bile duct (CBD). The postcontrast T2-weighted MRC showed loss of CBD signal, but persistent signal in the cystic duct remnant due to biliary stasis. Post-mangafodipir T1-weighted 3D gradient-echo images showed the main right and left hepatic ducts, but the cystic duct was not depicted. Conventional T2-weighted MRC sequences should not be obtained after administering mangafodipir trisodium because this contrast agent decreases the T2 and therefore the signal intensity of bile within normally functioning bile ducts. Functional MRC images can be acquired by using a post-mangafodipir T1-weighted technique.     

Intrahepatic bile duct dilatation shown by computed tomography--predilection for the left lobe?

Dilated biliary duct radicles were most obvious within the left lobe of the liver in 30 out of 42 patients with obstructive jaundice in whom intrahepatic duct dilatation was satisfactorily demonstrated by computed tomography. In 19 of these 30 patients the level of obstruction was at the lower end of the common bile duct. Recognition of this finding may prevent the erroneous diagnosis of intrahepatic or multiple obstructing lesions.     

MRCP在梗阻性黄疸中医辨证分型中的应用研究

目的:探讨磁共振胆胰管成像(MRCP)在黄疸中医辨证分型中的应用价值。方法:对72例梗阻性黄疸患者进行MRI及MRCP检查,同时进行中医辨证分型,并与临床诊断、化验结果或手术和病理结果对比分析。结果:72例梗阻性黄疸病例中医辨证阳黄30例,主要以结石、炎症、先天囊肿为主;阴黄42例,主要以肝内、肝外肿瘤为主,并发现肝外胆管扩张程度阴黄高于阳黄。前者以重度和中度黄疸为主,占38/42,且形态以软藤状为主,占38/42;后者以轻度和中度黄疸为主,占28/30,且形态以枯枝状为主,占17/24。结论:MRCP图像清晰,能清楚显示扩张肝内胆管、胆总管、胆囊的形态、部位以及与周围组织结构的关系,对梗阻性黄疸中医辨证分型的诊断具有一定指导价值。     

Segmental intensity differences in the liver on MR images: a sign of intrahepatic portal flow stoppage

Segmental intensity differences (SIDs) in hepatic parenchyma free of tumor were noted in six patients with hepatic masses (hepatocellular carcinoma in five and metastatic liver cancer in one). Areas of SID were homogeneous in intensity. The intensity of the affected region was high in all six patients on T2-weighted magnetic resonance (MR) images and low in two on T1-weighted images. Three of five patients examined with plain computed tomography (CT) had corresponding segmental areas of low attenuation. Angiograms obtained in five patients showed occlusion of the intrahepatic portal vein, segmental staining corresponding to the region of the SID, or both. Twelve of 82 patients examined with MR imaging and angiography had similar findings on angiograms, and ten of them had abnormal intensity of anatomic distribution around or beside the liver tumors on MR images. MR imaging may be more sensitive than plain CT in the detection of secondary changes caused by intrahepatic portal flow stoppage.     

Oriental cholangiohepatitis: sonographic findings in 48 cases

Oriental cholangiohepatitis is characterized by recurrent attacks of abdominal pain, fever, chill, and jaundice and grossly dilated extrahepatic and intrahepatic ducts containing soft, pigmented stone and pus. Sonograms were studied in 48 patients in whom the diagnosis was later proved during surgery (n = 34) or on the basis of clinical and laboratory findings and endoscopic retrograde cholangiography (n = 14). The sonographic findings included intrahepatic and/or extrahepatic bile duct stones (n = 47); moderate to severe dilatation of the extrahepatic ducts with relatively mild or no dilatation of intrahepatic bile ducts (n = 41); localized dilatation of the lobar or segmental bile ducts, especially the left hepatic lobe (n = 16); and gallstones (n = 22). Our experience suggests that the preoperative diagnosis of oriental cholangiohepatitis can be strongly suggested by sonographic findings.     

肝外胆管梗阻病变CT诊断的评价

目的：通过分析良恶性肝外胆管梗阻病变的ＣＴ表现，总结出有鉴别诊断意义的征象。材料与方法：复查分析经手术和病理证实、术前均做了ＣＴ检查的肝外胆管梗阻病变１１７例，良性３８例，恶性７９例。结果：肝外胆管远段梗阻，梗阻部胆管呈漏斗样改变，肝外胆管壁呈环形弥漫型增厚，肝内胆管呈竹节状或小囊状轻、中度扩张，梗阻部肿块内钙化，边界清楚对良性病变诊断有重要意义；肝外胆管中、近段梗阻或肝外胆管未显影者，梗阻部胆管呈截断型或突然狭窄型并伴肿块，肝外胆管壁呈环形局限型增厚，肝内胆管呈藤状或蟹足状中度或重度扩张，梗阻部肿块边界不清，其内可见坏死等征象，高度提示恶性病变。结论：良恶性肝外胆管梗阻病变均有其特征性的ＣＴ征象，注意观察胆管的形态改变，以及与周围组织结构关系，并紧密结合临床综合分析，有助于提高诊断准确性。     

Dilated biliary tract: evaluation with MR cholangiography with a T2- weighted contrast-enhanced fast sequence

A heavily T2-weighted gradient-echo sequence was used for magnetic resonance (MR) imaging of the biliary system in five healthy volunteers and 13 patients with obstructive jaundice. Images were obtained in the sagittal and coronal planes during sequential breath-hold intervals and were post-processed by using a maximum-intensity projection algorithm. The extrahepatic and intrahepatic bile ducts were well visualized in 11 patients. The level of obstruction and the grade of dilatation were depicted with MR cholangiography. However, the cause of obstruction could be determined with MR cholangiography in only eight cases. The part of the biliary system below the obstruction could not be visualized with MR cholangiography. In the volunteers, MR cholangiography could demonstrate the anatomy of the biliary tract in only two subjects. Possible causes for this phenomenon are the limited spatial resolution of MR imaging, partial volume effects, or flow within the bile ducts. MR cholangiography may be a useful adjunctive tool for noninvasive evaluation of patients with obstructive jaundice. However, further technical advances are necessary to improve image quality.     

肝细胞癌合并胆管癌栓的影像表现

目的 探讨胆管癌栓的影像表现,以提高影像诊断水平.方法 回顾性分析经手术病理证实的肝细胞癌(HCC)胆管癌栓13例患者资料,其中3例进行了CT和MR检查,2例仅行CT检查,8例仅行MR检查,7例进行了MR胰胆管成像检查,13例均进行了超声检查.采用四格表Fisher 确切概率检验方法比较超声与CT、MR诊断HCC胆管癌栓的准确性.结果 13例HCC肿瘤及胆管癌栓均在CT或MRI上显示.4例胆管癌栓在CT上表现为胆管内软组织块影,动脉期可见癌栓轻度增强,癌栓远端胆管扩张.11例胆管癌栓在T1 WI上均呈稍低信号,T2 WI为稍高信号,增强后可见轻、中度强化.MR胰胆管成像上胆管癌栓表现为:胆管阻塞中断、狭窄或不规则充盈缺损伴有梗阻上方胆管扩张,胆管突然截断或呈"鼠尾"状(5例);肝内胆管扩张,癌栓充满整个胆总管.胆总管不显示(2例).超声检查准确诊断胆管癌栓7例,误、漏诊6例.CT、MRI准确诊断12例,误诊4例,超声与CT、MRI诊断胆管癌栓差异无统计学意义(P=0.270).结论 CT或MRI对诊断HCC合并胆管癌栓及明确癌栓范围有价值.     

Improved detection of metastatic melanoma by T2*-weighted imaging

BACKGROUND AND PURPOSE: The imaging features of metastatic melanomas are distinctive due to the presence of melanin and the propensity for hemorrhage. Both hemorrhage and melanin can produce T1-weighted hyperintensity and T2*-weighted signal intensity loss. We hypothesized that T2*-weighted images would improve detection of metastatic melanoma. METHODS: The T2* and T1 characteristics of 120 newly detected metastatic brain lesions from 31 patients with malignant melanoma were compared with those of 120 brain metastases from 23 patients with lung cancer. RESULTS: Melanoma metastases were 5 times more likely to demonstrate prominent T2*-related signal intensity loss (susceptibility effect) than were lung metastases (42% vs 8%; P < .01), and 4.5 times more likely to demonstrate T1 hyperintensity (55% vs 12%; P < .01). Patients with melanoma had lesions that were either hypointense on T2*-weighted images, hyperintense on T1 images, or both, in 71% (85/120), compared with 19% (23/120) of lung carcinoma metastases (P < .01). Melanoma lesions were 16 times more likely than lung cancer lesions to show combined T2* related signal intensity loss and T1 hyperintensity (P < .01). Remarkably, 8 melanoma lesions (7%) in 3 patients were detectable principally on the T2*-weighted sequences, whereas no lung cancer lesion was detected solely on susceptibility images. We found a direct correlation between melanin content and T1 hyperintensity but no correlation between T2* intensity and melanin. CONCLUSION: T2*-weighted images improve lesion detection in patients with melanoma metastases, and in conjunction with T1-weighted sequences, can suggest melanoma as the etiology of an intracranial mass. This sequence should be employed for evaluation of possible brain metastasis in patients without a known primary malignancy and in studies for melanoma staging.