Diagnostic accuracy of magnetic resonance cholangiopancreatography and ultrasound compared with direct cholangiography in the detection of choledocholithiasis

AIM: To determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and trans-abdominal ultrasound in the detection of choledocholithiasis, and to compare bile duct stone characteristics using endoscopic retrograde cholangiopancreatography (ERCP), MRCP and ultrasound. MATERIALS AND METHODS: Of 191 consecutive patients referred for diagnostic ERCP, choledocholithiasis was diagnosed in 34 patients using direct cholangiography. The latter took the form of ERCP (n = 29), intraoperative cholangiography (n = 3) or percutaneous transhepatic cholangiography (n = 2). All patients underwent MRCP and ultrasound examinations and their findings for choledocholitiasis were compared with those at direct cholangiography. Finally, in the 29 patients with choledocholithiasis diagnosed under ERCP, stone characteristics were compared across the three investigations of ERCP, MRCP and ultrasound. RESULTS: Compared with direct cholangiography, MRCP showed a sensitivity, specificity and diagnostic accuracy of 91%, 98% and 97%, respectively, in the diagnosis of choledocholithiasis. MRCP resulted in three false-negative and three false-positive findings, four of which occurred due to confusion with lesions at the ampulla. Ultrasound showed a sensitivity, specificity and diagnostic accuracy of 38%, 100% and 89%, respectively, in the diagnosis of choledocholithiasis. ERCP revealed a greater number of stones and these were more proximally distributed within the bile ducts when compared to MRCP. CONCLUSIONS: MRCP is highly accurate in the diagnosis of choloedocholithiasis and has the potential to replace diagnostic ERCP. MRCP underestimates the number of bile duct stones present.     

A prospective comparison of magnetic resonance cholangiopancreatography with endoscopic retrograde cholangiopancreatography in the evaluation of patients with suspected biliary tract disease.

AIM: To determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) compared with direct cholangiography in the detection of biliary tract disease. PATIENTS AND METHODS: MRCP was performed in 100 patients in whom direct cholangiographic correlation (ERCP, n = 98; PTC, n = 9; intraoperative cholangiography, n = 3) was available for comparison. The MRCP examinations were performed using a two-dimensional multi-slice, fast spin echo (FSE) technique and a local surface coil. The diagnoses at direct cholangiography were choledocholithiasis in 30 patients, benign and malignant strictures in 28 patients and normal bile ducts in 42 patients. The nature of the strictures (benign, n = 2; tumour, n = 18; lymphnode recurrence, n = 3; unknown histology, n = 5) was determined by one or more of the following procedures: surgery (n = 8), biopsy (n = 15), cytology (n = 6) and cross-sectional imaging/follow-up findings (n = 3). RESULTS: MRCP diagnosed choledocholithiasis with a sensitivity of 93%, specificity of 99% and accuracy of 97 %. It resulted in two false-negative and one false-positive findings when compared with direct cholangiography. MRCP accurately diagnosed the presence and level of strictures in all patients. The overall sensitivity, specificity and accuracy of MRCP in the detection of bile duct lesions were 97%, 98% and 97%, respectively. CONCLUSION: MRCP has a high diagnostic accuracy when compared with direct cholangiography in the detection of bile duct disease.     

不同影像检查方法诊断胆总管结石的比较研究

目的评价超声、多层螺旋CT(MSCT)、磁共振胆胰管成像(MRCP)、内镜逆行性胰胆管造影(ERCP)对胆总管结石的诊断价值。方法回顾分析在我院疑诊为胆总管结石的患者,选取同时行B超、MSCT及MRCP的94例患者,以ERCP相关治疗或手术为诊断胆总管结石的"金标准"进行统计分析。选取术前行MRCP检查,并经ERCP检查及治疗证实为胆总管结石的患者共65例,按结石大小分组统计比较MRCP、ERCP的诊断率。结果 B超、MSCT、MRCP诊断胆总管结石的敏感度分别为63.3%、74.7%、87.3%,特异度分别为53.3%、80.0%、86.7%,准确度分别为61.7%、75.5%、87.2%;2检验显示准确度由高到低分别为MRCP、MSCT、B超。分析不同大小的结石:MRCP独立诊断时三组结石准确度之间差异有统计学意义,对直径0.5cm及以下的微小结石显示不佳(P<0.05);ERCP独立诊断时三组准确度之间差异没有统计学意义;各组结石分别同时用MRCP与ERCP诊断,两种检查方法之间的准确度均没有统计学意义。结论 B超和MSCT诊断胆总管结石有一定的局限性,可作为胆总管结石首选的筛查方法,尤其是急诊患者;MRCP安全、无创伤,在一定程度上可以替代诊断性ERCP;ERCP对胆总管结石的诊疗方面具有较大临床优势。     

MR cholangiopancreatography versus endoscopic sonography in suspected common bile duct lithiasis: a prospective, comparative study

OBJECTIVE: Our purpose was to compare the accuracy of MR cholangiopancreatography and endoscopic sonography for the diagnosis of common bile duct stones in patients with a mild to moderate clinical suspicion of common bile duct stones. SUBJECTS AND METHODS: Forty-seven patients were prospectively enrolled. Inclusion criteria included acute pancreatitis, subclinical jaundice, and clinical features of common bile duct stone migration. Radial endoscopic sonography and MR cholangiopancreatography with the single-shot fast spin-echo technique were performed a maximum of 48 hr apart. The gold-standard diagnosis was obtained with ERCP (n = 20) or intraoperative cholangiography (n = 14) if the results of endoscopic sonography or MR cholangiopancreatography were abnormal or if a cholecystectomy was performed, or by clinical and biochemical follow-up (n = 11) if the results of endoscopic sonography and MR cholangiopancreatography were normal. RESULTS: The final diagnosis was common bile duct stones in 16 patients, malignant obstructions in four, and another biliary disease in two (lithiasis migration aspect with papillary edema); 23 patients had no biliary disease. The sensitivity and specificity of MR cholangiopancreatography were, respectively, 90.5% and 87.5% for etiologic diagnosis and 87.5% and 96.6% for the detection of common bile duct stones. The corresponding values for endoscopic sonography were 86.4% and 91.3% for etiologic diagnosis and 93.8% and 96.6% for visualization of choledocholithiasis. Accuracy did not significantly differ between the techniques. CONCLUSION: In cases of mild to moderate suspicion of choledocholithiasis, the accuracies of endoscopic sonography and MR cholangiopancreatography are similar. Because MR cholangiopancreatography is noninvasive, it may be preferred for this indication.     

Imaging patients with "post-cholecystectomy syndrome": an algorithmic approach

AIM: To assess the role of ultrasound (US), magnetic resonance cholangiopancreatography (MRCP) and liver function tests (LFTs) in the evaluation of selected patients presenting with late post-cholecystectomy syndrome (PCS) who were referred for endoscopic retrograde cholangiopancreatography (ERCP). MATERIALS AND METHODS: In a retrospective study a final group of 42 patients with PCS referred for diagnostic ERCP underwent MRCP and abdominal US. ERCP and MRCP images were assessed for bile duct diameters and the presence of strictures and stones. A common bile duct (CBD) diameter of < 10mm was considered normal, whereas > or = 10mm was considered abnormal on US. Findings were correlated to LFTs with contingency table results performed for single techniques and combination of methods. RESULTS: In total 14 stones and one stricture were seen. US had a high negative predictive value (86.4%). MRCP had a sensitivity of 100% and specificity of 88.0%. ERCP is the most accurate test but failed in 11 patients, five of whom had a stone. The accuracy of US and LFTs increases to 93.8% if test results agree in either negative or positive outcome. CONCLUSION: US and LFTs are first-line tests in PCS. If the CBD on US is > or = 10mm, but no cause is identified, MRCP should be performed. If US and LFTs are normal then MRCP is not necessary. The availability of LFTs raises the diagnostic value of imaging.     

胆管癌误诊和漏诊的影像学分析

目的：分析胆管癌误诊和漏诊的原因，评价不同检查方法对肝门区胆管癌诊断的价值，提高胆管癌的影像学诊断和鉴别诊断水平。方法：收集31例临床和病理诊断为胆管癌的病例(ERCP检查31例，B超检查31例，25例CT检查，11例行MRCP检查)，回顾性分析不同检查方法的影像学表现。结果：31例中发生在肝门区的胆管癌25例。2例初次ERCP显示胆管内出血，再次行鼻胆管造影后诊断为胆管癌，4例合并有总胆管结石。6例为总胆管中下段癌。初次诊断准确性为90．3％。11例MRCP中9例显示病变，2例显示不满意，7例显示胆管或胆囊结石。25例CT中23例显示肝内胆管扩张，9例显示肝门区肿块，2例见后腹膜转移淋巴结，1例见肝内多发性转移瘤。12例初次诊断正确(48％)。B超检查23例提示肝内胆管扩张，6例提示总胆管结石，18例诊断为胆囊炎、胆囊结石，8例提示胆管占位(25．8％)。结论：良好的直接胆管造影是诊断胆管癌的金标准，MRCP可以在一定程度上准确显示病变的范围，是ERCP的良好补充，很大程度上取代了诊断性ERCP；CT诊断的关键在于显示扩张的胆管和梗阻的定位，肝门区梗阻多为胆管癌所致。多种影像检查方法的结合明显提高了诊断的准确性，对胆管癌治疗方案的选择有重要价值。     

Detection of common bile duct stones: comparison between endoscopic ultrasonography, magnetic resonance cholangiography, and helical-computed-tomographic cholangiography

OBJECTIVES: New modalities, namely, endoscopic ultrasonography (EUS), magnetic resonance cholangiopancreatography (MRCP), and helical computed-tomographic cholangiography (HCT-C), have been introduced recently for the detection of common bile duct (CBD) stones and shown improved detectability compared to conventional ultrasound or computed tomography. We conducted this study to compare the diagnostic ability of EUS, MRCP, and HCT-C in patients with suspected choledocholithiasis. METHODS: Twenty-eight patients clinically suspected of having CBD stones were enrolled, excluding those with cholangitis or a definite history of choledocholithiasis. Each patient underwent EUS, MRCP, and HCT-C prior to endoscopic retrograde cholangio-pancreatography (ERCP), the result of which served as the diagnostic gold standard. RESULTS: CBD stones were detected in 24 (86%) of 28 patients by ERCP/IDUS. The sensitivity of EUS, MRCP, and HCT-C was 100%, 88%, and 88%, respectively. False negative cases for MRCP and HCT-C had a CBD stone smaller than 5mm in diameter. No serious complications occurred while one patient complained of itching in the eyelids after the infusion of contrast agent on HCT-C. CONCLUSIONS: When examination can be scheduled, MRCP or HCT-C will be the first choice because they were less invasive than EUS. MRCP and HCT-C had similar detectability but the former may be preferable considering the possibility of allergic reaction in the latter. When MRCP is negative, EUS is recommended to check for small CBD stones.     

Diagnosis of intrahepatic stones: superiority of MR cholangiopancreatography over endoscopic retrograde cholangiopancreatography

OBJECTIVE: The purpose of this study was to compare the efficacy of MR cholangiopancreatography (MRCP) and endoscopic retrograde cholangiopancreatography (ERCP) for the diagnosis of intrahepatic stones. MATERIALS AND METHODS: Of the 318 patients who underwent MRCP examinations at our institution during an 18-month period, we identified 49 patients who subsequently underwent surgery or cholangioscopic stone removal with proof of intrahepatic stones. Thirty-four of these patients also underwent ERCP; they made up our study population. All images were interpreted for the presence of bile duct stones: MRCP images were interpreted independently by two reviewers, and ERCP studies were interpreted by one reviewer who was unaware of the MRCP findings. RESULTS: The sensitivity and specificity of MRCP for detecting intrahepatic stones were 97% and 93%, respectively, whereas those of ERCP were 59% and 97%, respectively. MRCP showed a significantly higher sensitivity than ERCP in the diagnosis of intrahepatic stones (p < 0.001). We found no significant difference between MRCP and ERCP in sensitivity or specificity for detecting calculi in the common duct or gallbladder. CONCLUSION: MRCP is a more effective diagnostic method than ERCP for the evaluation of intrahepatic stones.     

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。     

SSFSE-MRCP与ERCP对梗阻性胆管疾病的诊断价值比较

目的 比较单次激发厚层投射磁共振胰胆管成像（SSFSE-MRCP）（包括梗阻部位薄层扫描或增强扫描）和内镜逆行胰胆管造影（ERCP）对梗阻性胆管疾病的诊断价值。资料与方法 采用单次激发投射快速自旋技术,对51例临床怀疑胆管梗阻患者进行SSFSE-MRCP检查,并均行常规ERCP检查,对MRCP影像资料和ERCP进行对照分析,所有资料均经手术病理或ERCP检查证实。结果 SSFSE-MRCP图像清晰,检查成功率高;MRCP对胆管梗阻定位准确率100％,定性准确率为78．4％,ERCP定性准确率为70．6％。结论 MRCP安全、简便、无创伤,成功率高,对胆管梗阻疾病的定位诊断准确。结合ERCP检查,可提高胆管梗阻的定性诊断准确率。     

Helical CT without contrast in choledocholithiasis diagnosis

The goal of this study was to determine the diagnostic value of the helical CT without contrast in suspected cases of choledocholithiasis, comparing this test with endoscopic retrograde cholangiopancreatography (ERCP). Forty patients with possible choledocholithiasis were studied prospectively. There were 23 women and 17 men, ranging in age from 24 to 91 years. Helical CT was performed immediately before ERCP (time interval between the two procedures was less than 1 h). A biliary area previously selected was studied with a technique of pitch 1 and slice thickness of 3.2 mm. Average time was 30 s. Reconstruction with different increments and windows were made. Stone presence was evaluated in bile duct and Vater's ampulla. Biliary dilation was evaluated too. Endoscopic retrograde cholangiopancreatography found stones in 19 patients and absence of stones in 20. One case was failed, but stones in bile duct were demonstrated during intraoperative cholangiography. Helical CT demonstrated stones in 15 of the 19 patients with positive ERCP. There were no false positives with CT. Patients without stones in ERCP were also negative in CT. The patient having the failed ERCP was considered positive in CT. The CT sensitivity was 80 % and specificity was 100 %, with an accuracy of 90 %. Helical CT without contrast has sensitivity and specificity good enough to be used as a screening technique in patients with suspected choledocholithiasis. Received: 15 February 2000/Revised: 3 July 2000/Accepted: 5 July 2000     

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     

多层螺旋CT阴性法胰胆管成像与MRCP结合MRI诊断胆总管结石的对比分析

目的：探讨螺旋CT阴性法胰胆管成像（N-MSCTCP）对比MRCP结合MRI对胆总管结石的诊断价值。方法：收集临床疑诊胆道梗阻行腹部螺旋CT（MSCT）及MRCP检查的患者136例,MSCT扫描数据经后处理重建获得N-MSCTCP图像。两位医生采用盲法分别对N-MSCTCP及MRCP结合MRI图像作出梗阻定位及定性诊断。以ERCP及手术结果为标准,分别统计分析2种诊断方法对胆总管结石的诊断能力。结果：N-MSCTCP及MRCP结合MRI诊断方法诊断胆总管结石总的准确度分别为82.4%~84.6%和91.2%~92.6%。MRCP结合MRI检出胆总管微小结石阳性率明显高于N-MSCTCP（二者检出率分别为83.9%~87.1%和35.5%~45.2%）,差别有统计学意义（Fisher精确检验,P〈0.05）。两位阅片者间的诊断一致性很好（K〉0.75）。结论：对于胆总管结石N-MSCTCP与MRCP结合MRI均有较高的诊断准确度,而对于微小结石的检出MRCP结合MRI更有优势。     

Diagnostic accuracy of MRCP in choledocholithiasis

PURPOSE: To evaluate the accuracy of MRCP in diagnosing choledocholithiasis considering Endoscopic Retrograde Cholangiopancreatography (ERCP) as the gold standard. To compare the results achieved during the first two years of use (1999-2000) of Magnetic Resonance Cholangiopancreatography (MRCP) in patients with suspected choledocholithiasis with those achieved during the following two years (2001-2002) in order to establish the repeatability and objectivity of MRCP results. MATERIALS AND METHODS: One hundred and seventy consecutive patients underwent MRCP followed by ERCP within 72 h. In 22/170 (13%) patients ERCP was unsuccessful for different reasons. MRCP was performed using a 1.5 T magnet with both multi-slice HASTE sequences and thick-slice projection technique. Choledocholithiasis was diagnosed in the presence of signal void images in the dependent portion of the duct surrounded by hyperintense bile and detected at least in two projections. The MRCP results, read independently from the ERCP results, were compared in two different and subsequent periods. RESULTS: ERCP confirmed choledocholithiasis in 87 patients. In these cases the results of MRCP were the following: 78 true positives, 53 true negatives, 7 false positives, and 9 false negatives. The sensitivity, specificity and accuracy were 90%, 88% and 89% respectively. After the exclusion of stones with diameters smaller than 6 mm, the sensitivity, specificity and accuracy were 100%, 99% and 99%, respectively. MRCP accuracy was related to the size of the stones. There was no significant statistical difference between the results obtained in the first two-year period and those obtained in the second period. CONCLUSIONS: MRCP is sufficiently accurate to replace ERCP in patients with suspected choledocholithiasis. The results are related to the size of stones. The use of well-defined radiological signs allows good diagnostic accuracy independent of the learning curve.     

Diagnosis of choledocholithiasis and bile duct stenosis by magnetic resonance cholangiogram

We evaluated the diagnostic accuracy of magnetic resonance cholangiography (MRC) in the diagnosis of bile duct calculi and stenosis. Two-dimensional fast spin echo (FSE) MR cholangiograms were performed using torso multicoil array as a surface coil and respiratory triggering in 50 patients suspected of having bile duct disease. Coronal and axial images were acquired and reviewed prospectively by two radiologists. Direct cholangiographic correlation (endoscopic retrograde cholangiopancreatography [ERCP], intraoperative cholangiogram, percutaneous transhepatic cholangiogram) and surgery were available for comparison and were reviewed by two radiologists. The sensitivity, specificity and accuracy of MRC in diagnosing bile duct dilatation, choledocholithiasis and stenosis were evaluated. It yielded a sensitivity and a specificity of 100% in diagnosing bile duct dilatation. In the diagnosis of choledocholithiasis, MRC yielded a sensitivity of 95%, a specificity and an accuracy of 96%. Bile duct stenosis was diagnosed with a sensitivity and a specificity of 100%. We concluded that MRC exhibited high accuracy in diagnosing bile duct stenosis and choledocholithiasis.     

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.     

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     

Choledocholithiasis: repetitive thick-slab single-shot projection magnetic resonance cholangiopancreaticography versus endoscopic ultrasonography

This prospective study compares repetitive thick-slab single-shot projection magnetic resonance cholangiopancreatography (MRCP) with endoscopic ultrasonography (EUS) for the detection of choledocholithiasis. Fifty-seven consecutive patients (36 women, mean age 61) referred for suspected choledocholithiasis underwent MRCP, followed by EUS. Each procedure was performed by different operators blinded to the results of the other investigation. MR technique included a turbo spin-echo T2-weighted axial sequence with selective fat saturation (SPIR/TSE, TE=70 ms, TR=1,600 ms), followed by coronal dynamic MRCP. The same thick-slab slice was sequentially acquired 12 times as breath-hold single-shot projection imaging (SSh, TE=900 ms, TE=8,000 ms) centred on the common bile duct (CBD). Two experienced radiologists independently and blindly evaluated MR images for the detection of CBD stones. Their inter-observer agreement kappa was determined. Secondly, the two observers read MR images in consensus again. CBD stones were demonstrated in 18 out of 57 patients (31.6 %) and confirmed by endoscopic retrograde cholangiography (ERCP, n=17) or intraoperative cholangiography (n=1). Clinical follow-up served as the “gold standard” in patients with negative results without following invasive procedure (n=28). Sensitivity, specificity, accuracy, positive and negative predictive value for MRCP resulting from consensus reading were 94.9%, 94.4%, 94.7%, 97.4% and 89.5%, respectively. Corresponding values of EUS were 97.4%, 94.4%, 96.5%, 97.4% and 94.4%. Inter-observer agreement kappa was 0.81. Repetitive thick-slab single-shot projection MRCP is an accurate non-invasive imaging modality for suspected choledocholithiasis and should be increasingly used to select those patients who require a subsequent therapeutic procedure, namely ERCP.     

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.     

Comparative diagnostic evaluation with MR cholangiopancreatography, ultrasonography and CT in patients with pancreatobiliary disease

Purpose

The aim of this study was to directly compare the results of magnetic resonance cholangiopancreatography (MRCP) with those of ultrasonography (US) and multislice computed tomography (MSCT) in the diagnosis of pancreaticobiliary diseases.

Materials and methods

A total of 70 patients (41 men, 29 women) aged 22-89 years were studied either before (n=59) or after cholecystectomy (n=11) for biliary lithiasis. Clinical signs and symptoms were jaundice (n=15), abdominal pain (n=37) and proven biliary lithiasis (n=18). MRCP was performed in all patients, whereas abdominal US was performed in 55 (group 1) and MSCT in 37 (group 2) patients. A regional evaluation of the main structures of the pancreaticobiliary system was performed: gallbladder and cystic duct, intra- and extrahepatic bile ducts and main pancreatic duct. Histology (n=27), biopsy (n=5), endoscopic retrograde cholangiopancreatography (ERCP) (n=28) and/or clinical-imaging follow-up (n=10) were considered standards of reference. In particular, patients were classified as showing benign (n=47) or malignant (n=12) lesions or normal biliary anatomy (n=11).

Results

In group 1, the results of MRCP and US were concordant in the majority (92%) of cases; however, statistically significant discordance (p<0.01) was found in the evaluation of the extrahepatic ducts, with nine cases (16%) of middle-distal common bile duct stones being detected on MRCP only. In group 2, the results of MRCP and MSCT were also concordant in most cases (87%). However, findings were significantly discordant when the intra- and extrahepatic ducts were analysed, with seven (19%) and six (16%) cases, respectively, of lithiasis being detected on MRCP only (p<0.01 for both).

Conclusions

The results of our study confirm the diagnostic potential of MRCP in the study of the pancreaticobiliary duct system. In particular, the comparison between MRCP and US and MSCT indicates the superiority of MRCP in evaluating bile ducts and detecting stones in the common bile duct.