Malignant obstructive jaundice: comparison of MRCP and ERCP in the evaluation of distal lesions

PURPOSE: To compare the diagnostic accuracy of MR cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of malignant stenosis of the distal common bile duct. MATERIALS AND METHODS: Twenty-one patients (12 males and 9 females, mean age 62 years) with a clinical suspicion of malignancy of the distal biliary tract and pancreatic head underwent tomographic RM evaluation and diagnostic MRCP, followed by diagnostic and, where possible, therapeutic ERCP. The images obtained with ERCP and MRCP were reviewed blind by two experts who evaluated the presence, site, signal features and locoregional extension of the tumours. Histology performed by brushing or biopsy during ERCP and after surgical resection provided the standard of reference for all 21 patients. RESULTS: CPRM correctly identified the presence and site of the distal biliary stenosis in 21/21 (100%) cases, as well as allowing evaluation of the upper abdomen by associating it with conventional MRI. ERCP, instead, allowed detection of the presence and site of biliary stenosis in 20/21 (95%) cases. DISCUSSION AND CONCLUSIONS: ERCP may have some limitations as regards identification of distal bile duct stenosis in cases of critical stenosis. The non-invasive nature and panoramic capabilities of MRCP and the fact that no contrast material is needed make MRCP the examination of reference in the diagnosis of malignant stenosis of the distal bile duct, also thanks to its ability to visualise the entire biliary tree in the presence of critical strictures of the common bile duct. The rationale for the use of ERCP lies in the possibility of taking histological samples and performing minimally invasive surgical interventions.     

胰胆管疾病的ERCP影像诊断

目的评价内窥镜逆行胰胆管造影(ERCP)对胰胆管疾病的诊断价值。方法回顾性分析了经手术或病理及临床证实胰胆管疾病480例的ERCP表现,并与CT,MRI,MRCP,超声及透皮肝穿刺胆道造影(PTC)等检查方法进行对比。结果正常胰胆管75例,先天性胆管囊肿14例,胆系结石292例,奥狄括约肌狭窄症46例,壶腹癌、胆管癌52例,胰管癌4例,胰腺炎2例,胰管结石3例,胆道蛔虫症9例,肝内胆管发育变异2例,胆囊管异位开口6例,胆道-腹腔漏2例,十二指肠乳头旁憩室9例,十二指肠乳头开口于憩室内2例,肝移植后吻合口狭窄2例,肝移植后吻合口狭窄并胆漏1例,肝移植后肝外胆管条状结石2例。结论ERCP及MRCP检查同为诊断胰胆管疾病的“金标准”,但每种影像学方法均有其优缺点,应根据患者情况选择。ERCP虽有一定的创伤性,但检查同时可行内镜下乳头括约肌切开术(EST)等微创治疗。     

MR cholangiopancreatography

Although MRCP is still an evolving technique, it has established itself as clinically useful and comparable with ERCP for the evaluation of various biliary or pancreatic ductal diseases. MRCP is not only comparable with ERCP in its diagnostic ability, but it has the tremendous advantage of being noninvasive. Furthermore, MR imaging is useful in patients with incomplete or failed ERCP, and in patients with certain biliary or gastrointestinal surgical procedures it is the imaging modality of choice. ERCP will remain an extremely important modality because of the great clinical importance for interventional biliary procedures with this technique. Nonetheless, MRCP may in the near future replace most of the diagnostic imaging of the biliary tree, with diagnostic results even more improved with further developments of hardware and technique.     

MR cholangiopancreatography: prospective comparison of a breath-hold 2D projection technique with diagnostic ERCP

The aim of this study was to compare prospectively a breath-hold projection magnetic resonance cholangiopancreatography (MRCP) technique with diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Seventy-six patients with suspected strictures or choledocholithiasis were referred for MRCP and subsequent ERCP examination, which were performed within 4 h of each other. The MRCP technique was performed using fat-suppressed rapid acquisition with relaxation enhancement (RARE) projection images obtained in standardised planes with additional targeted projections as required by the supervising radiologist. Two radiologists (in consensus) assessed the MRCP results prospectively and independently for the presence of bile duct calculi, strictures, non-specific biliary dilatation and pancreatic duct dilatation, and recorded a single primary diagnosis. The ERCP was assessed prospectively and independently by a single endoscopist and used as a gold standard for comparison with MRCP. Diagnostic agreement was assessed by the Kappa statistic. The MRCP technique failed in two patients and ERCP in five. In the remaining 69 referrals ERCP demonstrated normal findings in 23 cases, strictures in 19 cases, choledocholithiasis in 9 cases, non-specific biliary dilatation in 14 cases and chronic pancreatitis in 4 cases. The MRCP technique correctly demonstrated 22 of 23 normal cases, 19 strictures with one false positive (sensitivity 100 %, specificity 98 %), all 9 cases of choledocholithiasis with two false positives (sensitivity 100 %, specificity 97 %), 12 of 14 cases of non-specific biliary dilatation and only 1 of 4 cases of chronic pancreatitis. There was overall good agreement for diagnosis based on a kappa value of 0.88. Breath-hold projection MRCP can provide non-invasively comparable diagnostic information to diagnostic ERCP for suspected choledocholithiasis and biliary strictures and may allow more selective use of therapeutic ERCP. Received: 20 May 1998; Revision received: 26 November 1998; Accepted: 7 January 1999     

ERCP与MRCP对胆道恶性梗阻诊断价值的分析比较

目的比较内镜逆行胰胆管造影(ERCP)和磁共振胰胆管造影(MRCP)对胆道恶性梗阻性疾病的诊断价值。方法对383例胆道梗阻,经手术和(或)ERCP病理证实的142例恶性胆道梗阻患者ERCP和MRCP影像资料进行对比分析。结果MRCP和ERCP总确诊137例恶性梗阻,占96.4%;两种方法定位诊断率分别为92.3%和87.3%;定性诊断率为78.5%和89.8%。结论MRCP在诊断胆道恶性梗阻性疾病方面具有简便安全以及漏诊率低等优点,但误诊率较ERCP高;而ERCP如在诊治过程中与MRCP相结合注重影像学的诊断分析,则可以提高阳性检出率。两者结合使用可起互补作用。     

MR cholangiopancreatography (MRCP) at 0.5 T: technique optimisation and preliminary results

The aim of our study was to evaluate the feasibility of MR cholangiopancreatography (MRCP) at 0.5 T. To our knowledge no previous studies of MRCP have been performed at mid-field strength. Thirty-one patients with dilated biliary systems were examined with three-dimensional MRCP. All patients were studied with a 0.5 T superconducting magnet. A three-dimensional turbo spin-echo (TSE) sequence was acquired (TR = 3000 ms, TE = 700 ms, echo train length = 45; acquisition time = 14 min 10 s). Coronal images were post-processed with the MIP algorithm. Recently, the parameters have been optimised (TR = 3000 ms, TE = 700 ms, echo train length =128), reducing the acquisition time to 3 min. Endoscopic retrograde cholangiopancreatography (ERCP) was performed in 26 cases; 5 patients underwent percutaneous transhepatic cholangiography PTC. MRCP and ERCP images were evaluated by an experienced radiologist and an endoscopist. MRCP of diagnostic quality was acquired in all patients. Choledocholithiasis was correctly evaluated by MRCP in 12 of 12 patients, compared with 11 correct diagnoses by ERCP. The presence and the level of the stricture were accurately shown in 16 of 16 patients with MRCP and in 13 of 16 patients with ERCP. The peripheral biliary tree above the obstruction and pancreatic duct were better evaluated by MRCP in all cases. In 3 of 3 patients who had undergone bilio-enteric surgery, a correct evaluation of the site of the anastomosis was possible with MRCP. It is concluded that MRCP performed at mid-field strength allows good visualisation of the dilated biliary system. Excellent results have been obtained on comparison with ERCP. MRCP performed at mid-field strength could have the same clinical value as high field strength MRCP. Correspondence to: P. Pavone     

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.     

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     

MR cholangiopancreatography: technique, potential indications, and diagnostic features of benign, postoperative, and malignant conditions

The objective of this article is to review technical aspects, discuss potential clinical indications for MR cholangiopancreatography (MRCP) and demonstrate the spectrum of diagnostic findings in benign, postoperative, and malignant conditions. We describe our current imaging protocol in comparison with other available techniques. Using a non-breath-hold, heavily T2-weighted fast-spin-echo (FSE) sequence with or without respiratory gating we obtained coronal and axial source images and maximum intensity projections (MIPs) in 102 patients with suspected abnormalities of the biliary or pancreatic ducts. Based on this series we demonstrate the diagnostic appearance of a variety of benign, postoperative, and malignant conditions of the biliary and pancreatic ducts and discuss potential clinical indications for MRCP. The non-breath-hold FSE technique enables a consistent image quality even in patients who cannot cooperate well. Respiratory gating increased the rate of diagnostic examinations from 79 to 95 %. Acquisition of coronal and axial source images enables detection of bile duct stones as small as 2 mm, although calculi that are impacted and not surrounded by hyperintense bile may sometimes be difficult to detect. The MIP reconstructions help to determine the level of obstruction in malignant jaundice, delineate anatomical variants and malformations, and to diagnose inflammatory conditions, e. g., sclerosing cholangitis, the Mirizzi syndrome and inflammatory changes in the main pancreatic duct. The MRCP technique also correctly demonstrates the morphology of bilio-enteric or bilio-biliary anastomoses. Because MRCP provides sufficient diagnostic information in a wide range of benign and malignant biliary and pancreatic disorders, it could obviate diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in many clinical settings. The ERCP technique may be increasingly reserved for patients in whom nonsurgical interventional procedures are anticipated. Received 25 July 1996; Revision received 1 October 1996; Accepted 5 November 1996     

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.     

Comparison of endoscopic retrograde cholangiopancreatography with MR cholangiopancreatography in patients with pancreatitis

PURPOSE: To assess the usefulness of magnetic resonance (MR) cholangiopancreatography (MRCP) in the evaluation of disease in patients with acute or chronic pancreatitis. MATERIALS AND METHODS: MR imaging was performed at 1.5 T in 39 patients with chronic (n = 30) or acute (n = 9) pancreatitis. The patients underwent a pancreas MR imaging protocol that included an MRCP sequence. Comparison was made with findings at endoscopic retrograde cholangiopancreatography (ERCP), performed within 30 days. Three blinded readers used a scoring system to evaluate nine segments of the pancreatic and biliary ducts as depicted on the ERCP and MRCP images. MRCP image quality was also evaluated. RESULTS: Of 196 segments analyzed, 17 were not seen at MRCP (sensitivity, 91%). Of the segments visualized at MRCP, 14 were incorrectly characterized (accuracy, 92%). At MRCP, segments not detected or mischaracterized were either normal, slightly dilated, or narrowed. At ERCP, 42 segments in 19 patients were not visualized. MRCP findings were considered useful in all those cases. MRCP image quality was not interpretable in two cases due to artifacts. CONCLUSION: Very good correlation between ERCP and MRCP findings was demonstrated. Both modalities failed to depict pathologic conditions depicted by the alternative method. MRCP may obviate ERCP, particularly in patients who cannot undergo ERCP or in whom ERCP has been unsuccessful.     

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。     

Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging method for examining the biliary and pancreatic ducts. The technique uses heavily T2-weighted imaging, which produces high signal from bile and other static fluids by virtue of their long T2 time, while suppressing background signal. Fast scanning techniques, particularly half-Fourier fast spin-echo techniques, are continuing to improve image resolution and allow scans within short breath-holds, reducing the effects of respiratory movement. The MRCP method has reached a level of resolution and reliability where it may well largely replace diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in the near future. A review of MRCP techniques and imaging findings is presented with emphasis on half-Fourier imaging, with reference to potential clinical indications and limitations. Use of MRCP shows a high sensitivity and specificity for detection of biliary dilatation, calculi, strictures and anatomical variants. Experience with MR imaging of the pancreatic duct is less extensively described in the literature, but pancreatic duct dilatation, calculi and anatomy can now be reliably detected. However, as experience with MRCP increases, some sources of errors and limitations are becoming apparent, with image artefacts, and gas, blood or sludge within ducts potentially mimicking stones or strictures.     

磁共振胆胰管成像(MRCP)与ERCP或PTC临床诊断价值的比较

探讨磁共振胆胰管成像在临床上对不同胆胰管疾病的诊断价值。材料与方法：回顾分析２３例疑有胆囊病患者的ＭＲＣＰ图像，并与其对照的ＥＲＣＰ或ＰＴＣ的诊断结果相比较。ＭＲＣＰ在１．０Ｔ超导磁场中完成，采用快速自旋回波序列ＭＩＰ法重建。结果：２３例患者的ＭＲＣＰ成功率为１００％，１４周手术病例中，ＭＲＣＰ对胆胰管系统非肿瘤性病变和肿瘤性病变的诊断正确率分别为１００％和８３５，１例误诊。     

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。     

Pancreaticobiliary diseases. Comparison of 2D single-shot turbo spin-echo MR cholangiopancreatography with endoscopic retrograde cholangiopancreatography

PURPOSE: To compare the diagnostic value of MR cholangiopancreatography (MRCP) to that of endoscopic retrograde cholangiopancreatography (ERCP) in the diagnosis of various obstructive and nonobstructive pancreaticobiliary diseases. MATERIAL AND METHODS: We retrospectively reviewed 153 patients who had undergone both MRCP and ERCP Breath-hold, heavily T2-weighted images using 2D single-shot turbo spin-echo technique were obtained. MRCP and ERCP results were correlated with the final clinical diagnoses. Accuracy of MRCP and ERCP in the diagnosis of pancreaticobiliary diseases, detecting the cause and site of biliary obstruction, if present, and distinguishing malignant from benign cause of obstruction were compared. RESULTS: Success rates of MRCP and ERCP were 98.7% and 89.5%, respectively. The accuracy of MRCP and ERCP in detecting the site of biliary obstruction was 89.7% and 96.2%, and in detecting the cause of biliary obstruction 69.2% and 71.8%, respectively. The sensitivity, specificity and likelihood ratios for positive and negative tests for MRCP and ERCP in distinguishing malignant biliary obstruction from benign causes were 86.4%, 82.4%, 4.9, 0.2 and 88.6%, 94.1%, 15.1, 0.1, respectively. Concordance between the two tests was 91% (kappa coefficient 0.82, standard error of kappa 0.113, p<0.001). In the group of nonobstructive biliary diseases, accuracy of MRCP and ERCP in detecting cholecystolithiasis were 100% and 73.7%, and in detecting pancreatitis 57% and 14%, respectively. CONCLUSION: 2D single-shot turbo spin-echo MRCP can be performed as a complement to ERCP and can replace ERCP in high-risk patients and in case of unsuccessful cannulation.     

MRCP在胆系梗阻性病变中的应用及其与ERCP对照分析

目的比较MRCP与ERCP在探测胆系梗阻性病变中的准确性。方法收集经手术病理证实的胆系梗阻性病变28例，并将MRCP影像学图像与其ERCP图像对照分析。结果28例胆系梗阻性病例中，胆系结石7例，胆系肿瘤19例，其他胆系病变2例。MRCP检查全部成功，其图像与该患者ERCP图像极其相似，对胆系梗阻的显示成功率100％，均给予准确定位，确定梗阻病因的准确性为82．14％（23／28）；对ERCP检查失败或显示不佳的病例，MRCP获得了较为满意的诊断信息。结论MRCP可对胆系梗阻性病变进行准确定位和较好的定性诊断。其无创、安全可靠，可作为胆系梗阻性病变的首选检查方法。     

Imaging of the normal and abnormal pancreaticobiliary system with single-shot MR cholangiopancreatography: a pictorial review

Magnetic resonance cholangiopancreatography (MRCP) is a rapidly evolving non-invasive imaging modality that produces images of the pancreatic duct and biliary tree without the need for intravenous or oral contrast. The images are equivalent to those from endoscopic retrograde cholangiopancreatography (ERCP), but the non-invasive acquisition avoids the morbidity and mortality associated with diagnostic ERCP. Magnetic resonance cholangiopancreatography is indicated in patients who require only a diagnostic ERCP, who fail an ERCP or who are unable to undergo ERCP due to altered post-surgical anatomy. Other evolving indications include triaging of patients with obstructive jaundice into percutaneous or endoscopic management drainage pathways depending on the site, length and nature of the duct obstruction, thereby potentially decreasing the number of failed or unsuccessful ERCP. Pre-operative identification of anomalous biliary anatomy and choledocholithiasis prior to laparoscopic cholecystectomy promise to modify the pre-operative and operative management of the patient in order to minimize the risk of duct injury and unnecessary intra-operative dissection and cholangiography. The advantages of the technique include its non-invasiveness, the absence of contrast administration, its relative operator independence and the ability to evaluate both sides of an obstructed duct, thereby accurately evaluating stricture morphology and length. The disadvantages of MRCP compared to ERCP include its lack of an immediate therapeutic solution to duct obstruction, procedural cost, unit availability and the inability to evaluate patients with pacemakers or ferromagnetic implants.     

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。     

Chronic pancreatitis: MRCP versus ERCP for quantitative caliber measurement and qualitative evaluation

PURPOSE: To retrospectively compare-in patients with chronic pancreatitis-magnetic resonance cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) for measurement of main pancreatic duct (MPD) diameter by using area intensity measurement (AIM) at MRCP and full width at half maximum (FWHM) at ERCP and to retrospectively determine the accuracy of MRCP for depiction of pathologic changes by using ERCP as the reference standard. MATERIALS AND METHODS: The institutional review board approved this study and waived the need to obtain informed consent. Both MRCP and ERCP were performed in 24 patients with chronic pancreatitis (21 men, three women; mean age, 54 years +/- 14 [standard deviation]). The diameter of the MPD was determined by using both methods at the same sites in the head, body, and tail of the pancreas. MRCP and ERCP measurements involved AIM and FWHM techniques, respectively. For qualitative evaluation, visualization of the MPD and pathologic findings was also examined by using both methods. Paired t and Wilcoxon matched-pair signed rank tests were performed for the quantitative and qualitative evaluations, respectively. RESULTS: The mean diameter of the MPD at ERCP was 1.5 times larger, on average, than that at MRCP; differences were statistically significant for each segment, as well as for the entire duct system. For qualitative evaluation, MRCP tended to be superior to ERCP for delineation of the MPD. Overall sensitivity, specificity, and accuracy values of MRCP for delineating pathologic pancreatic changes were 88% (87 of 99), 98% (44 of 45), and 91% (131 of 144), respectively. CONCLUSION: Use of ERCP tends to result in overestimation of the caliber of the MPD. MRCP can enable accurate evaluation of the condition of the pancreatic duct and its changes in patients with chronic pancreatitis.