MRCP诊断梗阻性黄疸及其影像学对比研究

目的 探讨MRCP在梗阻性黄疸中的诊断价值。方法 对75例梗阻性黄疸患行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，并与US、CT和直接胰胆管造影进行比较，对照手术病理结果进行分析结果本组75例中MRCP确诊71例，误诊4例，确诊率95％，与直接胰胆管造影(92％）相近，明显高于US(74％)和CT(75％)。MRCP对梗阻性黄疸定位诊断准确率为100％。结论 MRCP作为无创性检查技术，完整清晰地显示胰胆管系统结构，提高了，梗阻性黄疸的定位和定性诊断率，为临床保守或手术治疗提供可靠依据，可作为梗阻性黄疸患的首选影像学检查方法。     

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.     

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) uses MR imaging to visualize fluid in the biliary and pancreatic ducts as high signal intensity on T2-weighted sequences; it is the newest modality for biliary and pancreatic duct imaging. MRCP is of proven utility in a variety of biliary and pancreatic diseases, including choledocholithiasis, congenital anatomic variants, chronic pancreatitis, post-cholecystectomy disorders, and neoplastic duct obstruction. MRCP is an evolving technique, but it has reached the stage of development where it is clinically useful and of comparable accuracy to conventional cholangiography. With further progress, it is likely that by the start of the new millennium MRCP will replace diagnostic endoscopic retrograde cholangiopancreatography as the modality of choice for imaging the biliary and pancreatic ducts.     

MRCP与ERCP、PTC诊断胆道梗阻性疾病的对比研究

目的 :探讨磁共振胰胆管成像 (MRCP)加梗阻部位薄层扫描或增强扫描、内镜逆行胰胆管造影 (ERCP)、经皮肝穿刺胆道造影 (PTC)对胆道梗阻的诊断价值。材料和方法 :回顾性分析 42例临床怀疑胆道梗阻患者的MRCP资料 (包括薄层或增强扫描 ) ,并与 18例ERCP、9例PTC比较 ,所有病例均经手术病理证实。结果 :MRCP加梗阻部位薄层扫描或增强扫描对胆管梗阻诊断准确率为 90 .5 % ,ERCP为 88.9% ,PTC为 88.9%。结论 :MRCP加梗阻部位薄层扫描或增强扫描对胆管梗阻具有重要诊断价值。     

CT and MR cholangiography: advantages and pitfalls in perioperative evaluation of biliary tree

Recent developments in imaging technology have enabled CT and MR cholangiopancreatography (MRCP) to provide minimally invasive alternatives to endoscopic retrograde cholangiopancreatography for the pre- and post-operative assessment of biliary disease. This article describes anatomical variants of the biliary tree with surgical significance, followed by comparison of CT and MR cholangiographies. Drip infusion cholangiography with CT (DIC-CT) enables high-resolution three-dimensional anatomical representation of very small bile ducts (e.g. aberrant branches, the caudate branch and the cystic duct), which are potential causes of surgical complications. The disadvantages of DIC-CT include the possibility of adverse reactions to biliary contrast media and insufficient depiction of bile ducts caused by liver dysfunction or obstructive jaundice. Conventional MRCP is a standard, non-invasive method for evaluating the biliary tree. MRCP provides useful information, especially regarding the extrahepatic bile ducts and dilated intrahepatic bile ducts. Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRCP may facilitate the evaluation of biliary structure and excretory function. Understanding the characteristics of each type of cholangiography is important to ensure sufficient perioperative evaluation of the biliary system.     

MR cholangiography: techniques and clinical applications

Magnetic resonance cholangiography (MRCP) is a new non-invasive imaging technique for the evaluation of bilio-pancreatic disorders. Different sequences, using both breathhold and non-breathhold techniques, have been employed in order to obtain MRCP images. The authors discuss the technical aspects, particularly focusing their attention on a non-breathhold, three-dimensional, fat-suppressed turbo-spin-echo sequence, optimized on a 0.5-T magnet with 15 mT/m gradients. Clinical applications of MRCP are evaluated, presenting data from both the literature and personal experience. The main indication for MRCP study is represented by the evaluation of common bile duct obstruction, with the aim of assessing the presence of the obstruction (accuracy 85–100 %) and, subsequently, its level (accuracy 91–100 %) and its cause. The utility of associating conventional MR images to MRCP in malignant strictures in order to characterize and stage the malignant lesions is also discussed. Finally, data are presented regarding the indications and utility of MR pancreatography in the evaluation of patients with chronic pancreatitis. Received 24 July 1997; Revision received 30 October 1997; Accepted 16 December 1997     

磁共振胰胆管成像在诊断胰胆管疾病中的价值

目的：评价磁共振胰胆管成像(MRCP)诊断阻塞性和扩张性胰胆管疾病的临床价值。方法：采用西门子symPhonyl．5T超导磁共振成像仪，对72例胰胆管系统疾病患和20例正常对照组进行MRI和MRCP成像，其中病变组22例进行Gd-DTPA动态增强。分析图像，将诊断结果与手术病理和超声、CT等其它影像检查结果对照。结果：MRCP能清晰显示正常胰胆管树的结构，能直观显示胰胆管扩张和梗阻的部位、形态、范围。检出率和定位率为94、3％，定性率为85．7％。MRI图像能帮助定性诊断。结论：MRCP是一种安全、有效的胰胆管系统影像检查方法，与MRI结合，对诊断和鉴别诊断胰胆管阻塞性和扩张性疾病有较高的临床诊断价值，     

Clinical impact of MR cholangiopancreatography in patients with biliary disease

PURPOSE: To evaluate the role of MR Cholangiopan-creatography (MRCP) as a first imaging modality in patients with suspected biliary tree pathology and indications to endoscopic retrograde cholangiopancreatography (ERCP). MATERIAL AND METHODS: Eighty-eight patients, with clinical signs of biliary tree pathology underwent MRCP, performed with a 1.5 T unit and a phased-array coil. Surgery, intraoperative cholangiography, percutaneous transhepatic cholangiography (PTC) or ERCP were regarded as the gold standard in patients with obstruction; the remaining patients underwent follow-up MRCP examinations at 6-9 months. The MR examination was performed with baseline T1w 2D FLASH and T2w TSE sequences, followed by the MRCP study (single-slab breath-hold RARE and multislice breath-hold HASTE sequences). The MR images were independently evaluated by two radiologists. RESULTS: MRCP showed normal findings in 20 patients; 68 patients had biliary duct dilatation. In 11 out of 68 patients MRCP did not identify any obstruction (9/11 were true negative cases). A diagnosis of benign obstruction was expressed in 36/59 patients (4 chronic pancreatitis, 29 choledocolithiasis, 4 inflammatory obstruction, 2 primary sclerosing cholangitis), with 1 false positive and 5 false negatives (sensitivity, specificity and diagnostic accuracy of 86%, 95% and 90%, respectively). MRCP identified 23 neoplastic stenoses (20/23 were true positives): the sensitivity, specificity and diagnostic accuracy values were 100%, 87% and 95%, respectively. MRCP correctly identified the level of obstruction in 100% of cases. CONCLUSIONS: MRCP may be considered as a first-step imaging method in patients with clinical signs of biliary disease. The workload of ERCP in the diagnostic stage could therefore be reduced and its use be reserved for therapeutic indications.     

Intrabiliary MR imaging: assessment of biliary obstruction with use of an intraluminal MR receiver coil

PURPOSE: The primary aim of this study was to determine whether intrabiliary magnetic resonance (MR) imaging is feasible in a clinical setting and to optimize MR imaging parameters for the technique. In addition, it was attempted to determine the accuracy of intrabiliary MR imaging in the setting of biliary obstruction of unknown cause. MATERIALS AND METHODS: Intrabiliary MR was performed prospectively in 15 patients with biliary obstruction of unknown cause. A 0.030-inch MR intravascular receiver coil was placed in an existing biliary tube. Intrabiliary MR was performed on a 1.5-T system. T1-weighted, T2-weighted, and single-shot fast spin-echo images were acquired. T1-weighted images were also acquired after the administration of a gadolinium contrast agent. Signal intensity analysis was conducted in the region of the common bile duct. Accuracy of intrabiliary MR, computed tomography (CT), MR, and cholangiography were determined by correlation with surgical pathologic findings. RESULTS: Intrabiliary MR was successfully performed in 14 of 15 patients. MR examinations were performed in less than 1 hour. The signal-to-noise ratio in the region of the common bile duct with the intrabiliary MR technique was increased by a factor of 9 compared with standard surface-coil MR imaging (P < .00001). The mean n-plane resolution achieved was 740 +/- 20 microm x 1,150 +/- 20 microm obtained with use of a field of view of 18 cm x 18 cm (range, 15-24 cm) and a matrix of 256 x 160. Of the pulse sequences tested, the gadolinium-enhanced T1-weighted image was the best for identifying tumor and delineating tumor margins. Intrabiliary MR had a higher sensitivity than CT (100% vs 50%), a higher specificity than cholangiography (80% vs 20%), and a better correlation (P = .015) with surgical pathologic findings than CT, MR imaging, or cholangiography. CONCLUSIONS: Intrabiliary MR was well tolerated in a clinical setting and provided high spatial resolution and excellent contrast between the biliary lumen and adjacent structures. Intrabiliary MR demonstrated an advantage in detecting the presence or absence of biliary malignancies compared with currently available standard imaging techniques. The technique may be useful to evaluate biliary obstruction of unknown cause.     

Kontrastverstärkte MR-Cholangiographie mit Gadolinium-EOB-DTPA

Magnetic resonance cholangiopancreaticography (MRCP) with heavily T2-weighted RARE and HASTE sequences has become an important imaging modality for the morphologic evaluation of intra- and extrahepatic bile ducts. However, for the diagnosis of functional biliary disorders, cholangiopancreaticography (ERCP) and endoscopic manometry, two invasive techniques with considerable morbidity and mortality, remain the standard. Biliary scintigraphy, secretin-stimulated MRCP, and secretin-stimulated endoscopic ultrasound have not proven to be sufficient to replace these techniques as they lack diagnostic accuracy and correlate poorly with manometry results. Contrast-enhanced magnetic resonance cholangiography (CE-MRC) uses hepatocyte-selective contrast agents that are eliminated by the biliary system. Therefore, these substances can serve as biliary contrast agents in T1-weighted MR imaging. This method makes a noninvasive functional evaluation of the hepatobiliary system possible. In the present article, our preliminary experience with Gd-EOB-DTPA-enhanced MRC is summarized and potential clinical applications of this method are discussed. Additionally, the article reviews publications evaluating a possible benefit of CE-MRC with other hepatobiliary contrast agents such as mangafodipir trisodium.     

Navigator-triggered isotropic three-dimensional magnetic resonance cholangiopancreatography in the diagnosis of malignant biliary obstructions: comparison with direct cholangiography

PURPOSE: To compare the diagnostic accuracy of navigator-triggered isotropic three-dimensional (3D) MR cholangiopancreatography (MRCP) using parallel imaging for malignant biliary obstruction with direct cholangiography. MATERIALS AND METHODS: A total of 23 patients with malignant biliary obstruction underwent MRCP and endoscopic retrograde cholangiopancreatography (ERCP)/percutaneous transhepatic cholangiography (PTC). Two observers retrospectively evaluated 3D-MRCP and ERCP/PTC and recorded the level of obstruction and extent of tumor along with their confidence. The quality of images and morphologic appearance of stricture were also evaluated by two reviewers. The results of MRCP and ERCP/PTC were compared with surgical and histopathological data. RESULTS: 3D-MRCP was of diagnostic quality and free of artifacts in all patients, whereas ERCP/PTC examinations failed in three patients. For the evaluation of level of obstruction, there was no statistical significance between 3D-MRCP and ERCP/PTC. 3D-MRCP was superior to ERCP/PTC in the assessment of anatomical extent of hilar bile duct involvement, but did not show statistical significance. The accuracy of 3D-MRCP in determining tumoral extent of hilar cancer was higher than that of ERCP/PTC, but it was not statistically significant. The image quality of 3D-MRCP was superior to ERCP/PTC. There was good agreement between morphologic appearance at MRCP and those at ERCP/PTC. CONCLUSION: 3D-MRCP can accurately assess the level of obstruction and extent of tumor in patients with malignant biliary obstruction.     

Multislice CT cholangiography using thin-slab minimum intensity projection and multiplanar reformation in the evaluation of patients with suspected biliary obstruction: preliminary experience

Thirty-three patients with suspected biliary obstruction were prospectively evaluated with multislice CT cholangiography using thin-slab minimum intensity projection (MinIP) and multiplanar reformation (MPR) to determine its usefulness and to compare with the comparative studies of endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), or percutaneous transhepatic cholangiography (PTC). CT cholangiography made correct diagnoses in all biliary obstructions except in two patients with common bile duct stones. The correspondence with the comparative study was 93.9%. Multislice CT cholangiography may be favorable in noninvasive evaluation of biliary obstructions.     

恶性胆道梗阻的MRCP诊断(附21例分析)

目的　评价MRCP对恶性胆道梗阻的诊断价值。方法　 2 1例经临床及CT发现恶性胆道梗阻者行MRCP检查 ,结合MR平扫及手术病理对照。结果　MRCP对恶性胆道梗阻有较高的诊断率 ,6 8%～ 10 0 %。扩张的肝内胆管呈枯枝样或腊肠样 ,低位梗阻的胆总管末端大多呈截断状、杯口状或鼠尾状。结论　MRCP诊断恶性胆道梗阻准确率高 ,可作为不宜行ERCP的替代检查方法。     

肝外胆管梗阻的磁共振胆胰管造影诊断

目的 评价磁共振胆胰管造影（ＭＲＣＰ）对肝外胆管梗阻性疾病的临床诊断价值。方法 对５４例肝外胆管梗阻性疾病（肝外胆管结石３０例,恶性胆管梗阻２４例）进行ＭＲＣＰ检查,并与临床诊断或手术和病理结果对照分析。ＭＲＣＰ采用不屏气快速自旋回波（ＴＳＥ）序列重工Ｔ２ＷＩ扫描,结合呼吸触发及脂护抑制技术,原始图像以最大信号强度投影（ＭＩＰ）法进行三维重建。结果 全部５４例ＭＲＣＰ检查均一次成功,５２例胆胰管显     

Breath-hold magnetic resonance cholangiopancreatography in the evaluation of malignant pancreaticobiliary obstruction

OBJECTIVE: This study was designed to determine the effectiveness of magnetic resonance cholangiopancreatography (MRCP) using a breath-hold single-shot fast spin echo (SSFSE) technique in imaging patients with malignant biliary and/or pancreatic duct obstruction. METHODS: One hundred thirty-one breath-hold MRCP studies in patients with malignant pancreatic and/or biliary obstruction were evaluated. Pathologic diagnoses included pancreatic cancer, biliary malignancy, gallbladder carcinoma, hepatic neoplasms, malignant lymphadenopathy, and ampullary carcinoma. Two observers independently reviewed the images in a blinded fashion to assess the level of obstruction and the site of underlying tumor. RESULTS: The level of obstruction was correctly identified in 104 of 131 cases (79%) by observer 1 and in 107 of 131 cases (82%) by observer 2. The site of underlying tumor was correctly identified in 113 of 131 cases (86%) by observer 1 and in 110 of 131 cases (84%) by observer 2. CONCLUSION: Magnetic resonance cholangiopancreatography utilizing the SSFSE technique can accurately assess the level of obstruction and the site of underlying tumor in patients with malignant pancreaticobiliary obstruction, without the risks of cholangiography. This MRCP technique allows for visualization of intra- and extraductal anatomy and pathology.     

Rationale diagnostic approach to biliary tract imaging

Summary Since the introduction of MR cholangiography (MRC) diagnostic imaging of the biliary tract has been significantly improved. While percutaneous ultrasonography is still the primary examination, computed tomography (CT), conventional magnetic resonance imaging (MRI), as well as the direct imaging modalities of the biliary tract – iv cholangiography, endoscopic-retrograde-cholangiography (ERC), and percutaneous-transhepatic-cholangiography (PTC) are in use. This article discusses the clinical value of the different diagnostic techniques for the various biliary pathologies with special attention to recent developments in MRC techniques. An algorithm is presented offering a rational approach to biliary disorders. With further technical improvement shifts from ERC(P) to MRC(P) for biliary imaging could be envisioned, ERCP further concentrating on its role as a minimal invasive treatment option.      

HASTE MRCP and MRI findings in alveolar echinococcosis of the liver

Alveolar echinococcosis is a rare mass-producing inflammatory process of the liver. Experience with MRI, and particularly magnetic resonance cholangiopancreatography (MRCP), demonstrates that features of this disease are limited. The HASTE (half-Fourier acquisition single-shot turbo spin echo) MRCP and MRI findings of alveolar echinococcosis of the liver are presented in this report. HASTE MRCP was used to define the biliary system and the biliary system-mass relationship. It was found that results were comparable with those of invasive techniques such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography.     

Malignant hilar and perihilar biliary obstruction: use of MR cholangiography to define the extent of biliary ductal involvement and plan percutaneous interventions.

PURPOSE: To determine the usefulness of magnetic resonance (MR) cholangiography in defining the extent of biliary ductal involvement in patients with malignant hilar and perihilar biliary obstruction and to evaluate whether findings at MR cholangiography alone are sufficient to plan percutaneous interventions in these patients. MATERIALS AND METHODS: Twenty-nine patients with malignant hilar and perihilar biliary obstruction were examined with MR cholangiography. Two radiologists evaluated MR images and determined the extent of biliary ductal involvement. A hypothetical plan for biliary drainage was established prior to any intervention. All patients underwent percutaneous cholangiography, and 27 of 29 patients also underwent biliary drainage and/or stent placement within 7 days after MR cholangiography. By using direct cholangiography as the standard of reference, the usefulness of MR cholangiography in defining the extent of biliary ductal involvement was determined. The type of drainage performed was compared with the type that had been anticipated at MR cholangiography. RESULTS: MR cholangiography was adequate in helping predict the extent of biliary ductal involvement in 28 (96%) of 29 patients and led to underestimation of the extent of the disease in one patient. The therapeutic plan anticipated with MR cholangiography matched the one actually used in 24 (83%) of 29 patients. CONCLUSION: The high accuracy of MR cholangiography for defining extent of ductal involvement in patients with malignant hilar and perihilar obstruction allows adequate planning of percutaneous interventions in a majority of patients.     

Diagnostic imaging of carcinomas of the gallbladder and the bile ducts

Early diagnosis and accurate staging of carcinomas of the gallbladder and the bile ducts are helpful in improving the prognosis. Ultrasonography (US), a useful initial modality when exploring the background of jaundice or non-specific gastrointestinal complaints, sensitively reveals bile duct obstruction in particular. In unclear cases, or if US suggests a resectable biliary malignancy, computed tomography (CT), magnetic resonance imaging (MRI) with magnetic resonance cholangiography (MRC) and / or traditional cholangiography often provide additional information, and imaging-guided fine-needle biopsy or an endoscopic brush sample may verify the malignant nature of the tumor. Complementary modalities are usually needed for accurate staging, and traditional cholangiography is often performed for therapeutic purposes as well. Comparative studies of MRI with MRC and multidetector CT in biliary cancers would be welcome.     

MR cholangiopancreatography at 0.5 T with a 3D inversion recovery turbo-spin-echo sequence

The objective of this study was to assess the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) at 0.5 T. The MRCP technique was performed in 28 patients with symptomatology referrable to the biliary system. A three-dimensional (3D) inversion recovery turbo-spin-echo (TSE) sequence was used to create 3D reconstructions of the bile ducts. Dilation of the biliary tree or pancreatic duct in 23 patients due to tumor, calculi, or strictures was depicted with excellent contrast resolution. The approximate level of obstruction and all calculi were accurately predicted by MRCP. In another 3 patients no cause was found for the biliary dilatation. In the last 2 cases no abnormalities were found by either MRCP or endoscopic retrograde cholangiopancreatography (ERCP). The MRCP technique at 0.5 T is an accurate method for the assessment of pathology of the biliary tree. Received 23 August 1996; Revision received 31 January 1997; Accepted 5 February 1997