MR versus multislice CT cholangiography in evaluating patients with obstruction of the biliary tract

BACKGROUND: We compared magnetic resonance cholangiography (MRC) with multislice computed tomographic (MSCT) cholangiography in the assessment of patients with bile duct obstruction. METHODS: Thirty-six patients with clinical or biochemical signs of biliary obstruction were prospectively studied. MRC was performed with fast spin-echo and single-shot fast spin-echo sequences. Source images, maximum intensity projection, and multiplanar reconstruction were evaluated. MSCT cholangiography was performed without biliary contrast agent, with intravenous injection of 150 mL of iodinated contrast material at 4 mL/s, 2.5-mm slice thickness, 7.5-mm/s table speed, and 1.25-mm reconstruction interval. Axial, multiplanar, and minimum intensity projection reformatted images were evaluated. MRC and MSCT findings were compared with endoscopic retrograde cholangiopancreatography (ERCP; 20 patients), percutaneous cholangiography (eight patients), intraoperative cholangiography (two patients), surgery (11 patients), and cytology (11 patients) with respect to cause and site of obstruction. RESULTS: With regard to presence and site of obstruction, agreement was observed across MRC, MSCT cholangiography, and reference investigations in all cases. Concerning cause, the correct diagnosis was made by MSCT cholangiography in 34 of 36 patients. Two cases of common bile duct lithiasis, diagnosed on MRC and ERCP, were missed by MSCT cholangiography. CONCLUSION: MSCT cholangiography can be considered a possible noninvasive alternative to MRC.     

磁共振胆道造影(MRC)在胆道梗阻诊断中的价值

目的:通过MRI胆道造影（MR choingigraphy,MRC）与 CF,US,PTC/ERCP及手术、病理的对照研究,评价MRC显示胆道梗阻部位、确定梗阻原因的能力。材料和方法:30例梗阻性黄疸的患者在GE Signa.1.5T超导系统上进行了 MRC检查,并与PTC/ERCP、CT、US手术及病理对照。结果:本组资料中,MRC显示胆道梗阻的部位准确性达100％,优于有损伤性的胆道造影PTC或ERCP。MRC确定梗阻原因的准确性70％,相似于PTC/ERCP、CT、US。结论:我们的初步研究结果表明,无损伤性的MR胆道造影在梗阻性黄疸的定位和定性上具有很高的敏感性,准确性。对于梗阻性黄疸,特别是ERCP失败和不宜行PTC或ERCP的病人是最有效的替代方法。     

Bile duct disease: Prospective comparison of ERCP,CT, and fat suppression MRI

The authors compared computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP), techniques commonly used to study the biliary tree, with pre- and post-Gd-DTPA breath-hold fast low angle shot (FLASH) and fat suppressed spin-echo in 28 consecutive patients with bile duct abnormalities detected on ERCP, including 11 patients with malignant disease and 17 patients with benign disease. ERCP, CT, and magnetic resonance (MR) images were prospectively interpreted in a blinded fashion and reviewed by consensus. ERCP characterized all cases of malignant disease by the presence of a narrowed bile duct lumen with irregular margins. CT and MRI detected all cases of malignant disease and characterized nine of 11 as malignant. In seven of these cases, CT and MRI showed thickening of extrahepatic bile duct walls >5 mm. MRI images showed intrahepatic-enhancing periportal tissue in four cases, which was not seen on CT images, and which was biopsyproven tumor extension. Benign disease was characterized on ERCP images by the demonstration of smooth tapered narrowings in 16 cases, whereas on CT and MR images it was characterized by mild to moderate dilatation of the intrahepatic bile ducts and wall thickness < 5 mm in 13 cases. Overall ERCP correctly characterized 27 cases as benign or malignant and CT and MRI both characterized 25. The results of this study show a trend that ERCP is superior to CT and MRI for characterizing bile duct disease.     

Magnetic resonance cholangiography

Magnetic resonance cholangiography (MRC) can be performed with data from a routine imaging protocol, without the need for additional pulse sequences or special equipment. We studied three patients with obstructive jaundice who underwent magnetic resonance imaging (MRI) of the liver. T2-weighted fat suppressed fast spin-echo sequences were processed with a maximum intensity projection algorithm to create three-di-mensional images of the dilated portions of the biliary tree. Results were correlated with endoscopic retrograde cholangiopancreatography and computed tomography. These images compare favorably with those acquired on scanners in which special breath-holding gradient echo protocols are used.     

Three-dimensional spiral CT cholangiography with minimum intensity projection in patients with suspected obstructive biliary disease: comparison with percutaneous transhepatic cholangiography

Background: To evaluate the diagnostic potential of spiral computed tomographic (CT) cholangiography with minimum intensity projection (minIP) in the diagnosis of patients with suspected biliary obstruction. Methods: Nine consecutive patients with obstructive biliary disease were enrolled in this study. Spiral CT data (3-mm slice thickness, pitch 1∼2:1) obtained 65 s after the start of contrast medium injection (150 mL Ultravist 370, 3 mL/s) were reconstructed at 1-mm intervals. Three-dimensional (3D) CT cholangiography with minIP (3D CTC) was generated with a Siemens software package. The quality of 3D CTC in its ability to demonstrate the anatomic detail, the level of obstruction, and the presence or absence of isolated hepatic segments was evaluated using percutaneous transhepatic cholangiography as a gold standard. Results: In all patients, 3D CTC demonstrated dilated intrahepatic ducts up to tertiary branches. 3D CTC correctly diagnosed the level of biliary obstruction and demonstrated isolated segments in all patients. In determining the cause of biliary obstruction, one patient with hilar cholangiocarcinoma was misdiagnosed as having biliary invasion by hepatocellular carcinoma. Conclusion: 3D CTC with minIP can determine the level and cause of biliary obstruction. 3D CTC can be obtained from regular thin-section helical CT data and may be a strong competitor against diagnostic magnetic resonance cholangiography because of its superior resolution and information on adjacent soft tissues and the duct itself. Received: 7 July 2000/Accepted: 23 August 2000     

肝外胆道梗阻的CT和MRI分析

目的探讨肝外胆道梗阻的多层螺旋CT和磁共振影像特征。方法选择经手术和病理证实的65例肝外胆道梗阻性病变患者,其中肝外胆道结石21例,慢性胰头炎2例,恶性胆道梗阻42例。使用多层螺旋CT多期增强扫描47例。使用1.5T超导MRI扫描仪检查18例,SE序列常规T1WI和T2WI横断和冠状面成像,MRCP使用单次激发厚层投射技术。结果47例中MSCT显示轻度胆总管及肝内胆管扩张3例,中度12例,重度32例,对肝外胆管梗阻程度的判断和定位准确率为97.9%,定性诊断准确率为87.2%。18例MRCP胆胰管显示满意,对肝外胆管梗阻程度的判断和定位准确率为100%,结合常规MRI图像定性诊断准确率为88.9%。结论MSCT与MRI检查可以对肝外胆道梗阻作出早期诊断,特别以MRCP能清楚显示扩张胆管的部位、形态及与周围组织结构的关系,优于CT。     

Diagnosis of intrahepatic and common duct stones: Combined unenhanced and contrast-enhanced helical CT in 1090 patients

Background We determined the accuracy of combined unenhanced and contrast-enhanced helical computed tomography (CT) for diagnosis of bile duct stones. Methods During a 12-month period, 1090 patients who underwent combined CT and endoscopic retrograde cholangiography (ERC) or percutaneous transhepatic cholangioscopy (PTC) were enrolled in this study. The results of prospective CT interpretation regarding the presence of bile duct stones were compared with results of endoscopic stone removal, PTC and with surgical results. In 70 patients, detectability of stones on CT was evaluated depending on stone types. Results Of 1090 study patients, 175 and 299 patients were confirmed to have intrahepatic and common duct stones, respectively. The sensitivity and specificity of combined CT were 73% and 98% for diagnosis of intrahepatic stones and 71% and 97% for common duct stones. Of 70 patients 24, 25, and 21 patients had cholesterol, black pigment, and brown pigment stones, respectively. Eleven of 24 cholesterol stones, 21 of 25 black pigment stones, and 15 of 21 brown pigment stones were detected on combined CT. Conclusion Combined CT is of limited sensitivity for detection of bile duct stones, especially in Western countries where cholesterol stones predominate. It may be of greater value in populations with a higher incidence of pigment stones. Other complementary imaging modalities are needed for patients with negative CT findings who are highly suspected to have biliary stones.     

ERCP后CT及MPR诊断肝外梗阻性黄疸病因(附24例分析)

目的:探讨ERCP后加做肝胆胰CT对肝外胆道梗阻病因的诊断价值。材料和方法:24例肝外胆道梗阻病人,经ERCP造影后立即进行CT扫描,应用MPR技术充分显示胆道及其周围情况。结果:24例中,胆管癌5例,胰头癌7例,壶腹癌1例,胆总管下端结石9例,胆总管炎2例,均经手术证实,无假阳性及假阴性。结论:ERCP后加做肝胆胰CT及MPR是诊断肝外梗阻性黄疸的一种可靠手段。     

Carcinoma of the cystic duct

Two patients with carcinoma of the cystic duct presented with obstructive jaundice due to extrinsic compression of the common hepatic duct by the tumor. Sonography and computed tomography showed dilatation of the intrahepatic bile ducts and gallbladder. In one patient, a calculus seen in the gallbladder neck suggested Mirizzi syndrome. In the other, a small soft tissue mass was indistinguishable from a common duct tumor or an enlarged lymph node. In both cases, direct cholangiography demonstrated extrinsic compression and displacement of the common duct with proximal biliary dilatation and nonvisualization of the gallbladder. Carcinoma of the cystic duct should be considered whenever there is evidence of cystic duct obstruction and/or when cholangiography shows extrinsic mass effect on the common duct.     

Bile duct involvement in hepatocellular carcinoma: MR demonstration

Background: To determine the magnetic resonance (MR) features of hepatocellular carcinoma (HCC) with associated bile duct involvement. Methods: MR examinations of six patients (mean age, 62 years) demonstrating bile duct involvement due to HCC were retrospectively reviewed and compared to surgical and pathologic findings. Results: Three of the tumors were solitary, and three were multifocal. In two patients, MR showed direct biliary duct invasion by tumor. On T1-weighted MR images, four tumors were hypointense compared to the liver and two were isointense. On T2-weighted MR images, four tumors were hyperintense, and two were isointense. The two tumors studied with dynamic T1-weighted MR images obtained after intravenous administration of a gadolinium chelate, displayed enhancement similar to that of the liver. There was no evidence of a tumor capsule on either unenhanced or enhanced MR images. Intrahepatic bile duct dilatation was seen in five patients. The extrahepatic bile duct was normal in all cases. Conclusion: Although rare, HCC should be included when considering the etiology of intrahepatic bile duct obstruction. Imaging features suggestive of the diagnosis by MR include intrabiliary tumor or bile duct obstruction with an associated hepatic mass.     

Clinical value of MRC in the follow-up of liver transplant patients with a choledochojejunostomy

BACKGROUND: We investigated the clinical value of magnetic resonance cholangiography (MRC) in liver transplant patients receiving choledochojejunostomy (CDJ). METHODS: Twenty-five MRCs were performed in 23 initially asymptomatic patients 19 months (mean) after liver transplantation with biliary reconstruction via CDJ. The images were evaluated by consensus (two investigators) for bile duct strictures and dilatations. As a standard of reference, clinical follow-up (including laboratory analysis) was used in 20 cases and direct cholangiography or surgery in three cases. RESULTS: Fourteen pathologic findings were observed in 11 patients (anastomotic strictures in four, left or right bile duct strictures in three, and peripheral segmental dilatations with or without strictures in seven). Patients with pathologic MRC findings had significantly higher levels of alkaline phosphatase (p < 0.05) and more frequently had histories of cholangitis than did patients with normal MRC. Four of six patients with stenoses of the central bile ducts subsequently developed biliary complications requiring treatment (three confirmed by direct cholangiography). In patients with unremarkable bile ducts or only peripherally located changes on MRC, no bile duct complications or relevant changes in the cholestasis parameters occurred during follow-up (mean = 30 months). CONCLUSION: MRC can noninvasively detect pathologic biliary tract changes in liver transplant patients in the asymptomatic stage and provide information for planning invasive therapeutic procedures.     

MSCT的MinIP＋CPR技术在胆道梗阻中的应用价值

目的：探讨多层螺旋CT（MSCT）的最小密度投影（MinIP）联合曲面重建（CPR）即MinIP＋CPR技术在胆道梗阻中的应用价值。材料和方法：收集45例经临床证实的梗阻性黄疸患者,均于MSCT扫描后进行MinIP＋CPR胆道成像并进行分析。结果：良性病变25例,其中胆管结石12例、胆总管炎症5例、胆囊结石并胆管炎6例、胰腺炎2例;恶性病变20例,其中胆管癌10例、胆囊癌侵犯或转移累及胆管3例、胰头癌累及胆管4例、壶腹部癌3例。MinIP＋CPR对良、恶性病变的定位准确率分别为92.0％和95.0％,定性符合率分别为88.0％和90.0％。MinIP＋CPR图像不同程度纠正了轴位及多平面重建（MPR）图像作出的定位、定量或定性诊断,尤其提高了对恶性病变的诊断准确率（P<0.05）。结论：MSCT的MinIP＋CPR技术能更直观清晰地显示病变的范围和性质,是胆道梗阻病变尤其是恶性病变检查的有效手段。     

Icteric-type hepatoma: magnetic resonance imaging and magnetic resonance cholangiographic features

Background: We evaluated the imaging features of magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRC) of icteric-type hepatoma and correlated these with the findings of endoscopic retrograde cholangiography (ERC), percutaneous cholangiography, and surgery. Methods: Thirteen patients with viral hepatitis complicated by cirrhosis of the liver and obstructive jaundice underwent MRC and dynamic MRI. Five patients received percutaneous transhepatic cholangiography and drainage; one of these patients also underwent resection of the left hepatic lobe. Another patient received MRC followed by thrombectomy and T-tube insertion. ERC and endoscopic nasobiliary drainage were performed in another patient for bile diversion. Results: Primary liver tumors and dilatation of biliary system were demonstrated in all patients. No capsule formation could be found in any primary liver tumors. MRI showed the simultaneous presence of an intraluminal tumor in the portal trunk and common hepatic duct in eight patients. Three different MRC features were found: (a) an oval defect in the hilar bile duct(s) with dilated intrahepatic ducts (n= 9), (b) dilated intrahepatic ducts with missing major bile ducts (n= 2), and (c) localized stricture of the hilar bile duct(s) (n= 2). Conclusion: The presence of one or more of the following features in multiplanar MRI and MRC help to identify this rare, specific type of hepatocellular carcinoma: (a) the presence of an intraluminal tumor in both the portal trunk and the common hepatic duct, (b) enhancement of the intraluminal tumor in the common hepatic duct on the arterial phase, (c) type I MRC feature, and (d) hemobilia, blood clot within the gallbladder, and/or type II MRC feature. Received: 12 January 2000/Revision accepted: 12 July 2000     

多层螺旋CT阴性法胆管造影诊断胆管梗阻

目的评价多层螺旋CT(MSCT)阴性法胆管造影(N-CTCP)对胆管梗阻的诊断价值。方法对60例怀疑有胆管梗阻的病例进行N-CTCP成像,使用曲面重建(CPR)和最小密度投影(Min-IP)技术对有无胆管梗阻、梗阻部位及梗阻病变的性质进行评价,并将其结果与手术和(或)病理结果对照。结果60例均一次屏气完成扫描,N-CTCP成像显示胆管满意,CPR加Min-IP对胆管梗阻的定位诊断与定性诊断的灵敏度分别为89.86%、88.64%,特异度分别为94.59%、81.25%,阳性预测值分别为91.18%、92.86%,阴性预测值分别为93.75%、72.22%,阳性似然比分别为16.61、4.73,阴性似然比分别为0.11和0.14。结论N-CTCP对胆管梗阻性疾病定位准确,对良性及恶性胆管梗阻判断有较高准确性。     

Three-dimensional reconstructed images using multidetector computed tomography in evaluation of the biliary tract

The recent development of multidetector computed tomography (MDCT) and the parallel escalation in the capabilities of the workstation allow the use of high-quality multiplanar and three-dimensional reconstruction images. As a noninvasive technique, MDCT dedicated to the biliary tract represents an alternative to magnetic resonance cholangiography. The usefulness of three-dimensional reconstructed images using MDCT in evaluating biliary tract abnormality is illustrated.     

磁共振胰胆管成像对梗阻性黄疸的定性研究

目的:探讨磁共振胰胆管成像(MRCP)对胆道梗阻性疾病的诊断价值。方法:使用1.5T磁共振扫描仪,对489例可疑胆管梗阻性疾病及正常人行MRCP检查,原始图像作三维重建,然后分析其影像表现及诊断结果。结果:MRCP能清晰显示胰胆管的解剖结构,对胆道梗阻程度和梗阻部位判断的确诊率达100%。恶性梗阻的胆管扩张程度较良性梗阻重。结合MRCP原始图像和常规MRI能明确显示肿瘤大小及范围。MRCP鉴别良恶性梗阻的敏感性为92%,特异性为97%,准确性为95%。结论:MRCP检查的成功率高,胰胆管解剖结构显示清晰,适用于各种胰胆管疾病的诊断,可为恶性胰胆肿瘤术前可切除性提供评价,可作为该系统疾病诊断的首选方法。     

胆管扩张时线条样假性充盈缺损病变的磁共振胰胆管成像(MRCP)表现及意义

目的探讨MRCP中胆管内线条样充盈缺损的表现及成因.方法分析300例胆总管扩张病人和50例正常人的MRCP,所见与轴位T2WI、T1WI、B超及ERCP检查和(或)手术相对照.结果 MRCP图像中胆总管内线条样充盈缺损见于中-重度扩张胆总管,但B超、ERCP检查和外科手术未能证实其存在.结论 MRCP图像中扩张胆总管中央的线条样低信号很可能是由胆汁流动形成的假性病变或伪影.     

Diagnostic pitfalls in the cholangiographic diagnosis of choledochoceles: cholangiographic quality and its effect on visualization

Background: We wanted to establish reasonable cholangiographic diagnostic criteria by determining the sensitivity of cholangiography in detecting choledochoceles and those factors that could compromise visualization of choledochoceles. Methods: Over 4 years, 21 patients (seven male, 14 female; mean age = 67 years) were confirmed as having choledochoceles on endoscopic retrograde cholangiopancreatography (ERCP). Cholangiographic diagnosis was made by following three criteria: a radiolucent halo around the distal common bile duct (CBD), bulbous dilatation of the distal CBD, and the presence of sequential morphologic changes on serial cholangiography. Any two or more combinations of these three criteria were considered enough to diagnose a choledochocele on cholangiography. We compared cholangiographic imaging findings with the ERCP results. Results: Of 21 patients with choledochoceles, nine (43%) were correctly diagnosed on cholangiography. A radiolucent halo was present in six (28%) patients; four of these cases showed optimal duodenal filling, one showed faint duodenal filling, and one showed poor duodenal filling. The shapes of the distal CBD were bulbous, conelike, and blunt. Morphologic changes such as collapsing and bulging of the choledochocele could be seen in 12 (57%) patients on serial cholangiography. Waists were seen in 11 (52%), pseudowebs in four (19%), and wrinkling of the distal CBD in seven (33%). Conclusion: Cholangiography should be obtained with optimal timing and adequate conditions to diagnose choledochocele correctly. Received: 20 January 2000/Revision accepted: 31 May 2000     

Percutaneous transhepatic biliary drainage: Alternatives in left hepatic duct obstruction

The left-lobe subxiphoid approach has been the standard way to drain left hepatic duct occlusion. A new, right-side biliary drainage approach is described.Five patients, among 25 patients with bilateral biliary obstruction, were treated by an internalinternal drainage system. Three types of internalinternal drainage techniques are described: internal-internal luminal, type 1; internal-internal luminal, type 2; and internal-internal transductal, type 3.All 5 patients succeeded in biliary drainage. The internal-internal biliary drainage technique, performed from the right-side approach, is effective, avoids additional liver puncture and tract dilatation, and allows the combination of several biliary drainage techniques, adding greatly to the flexibility when treating intrahepatic obstruction. No complications were observed in our small series but special precaution should be taken with the transductal technique due to the possibility of bleeding.     

Bile leakage as a complication of liver biopsy in liver transplants

Four liver transplant recipients with intrahepatic bile duct leakage following liver biopsy are described. Two patients were clinically suspected of having a bile leak, one of whom had bile peritonitis. All four patients had elevated liver enzyme levels. In three patients, cholangiography showed contrast media leakage into the peritoneum through the needle biopsy tract; one leak was totally intraparenchymal. All patients had varying degrees of biliary obstruction. The differential diagnosis of bile leakage posttransplantation should include recent liver biopsy.