The role of 99mTc mebrofenin hepatobiliary scanning in predicting common bile duct stones in patients with gallstone disease

BACKGROUND: A dilated common bile duct and/or elevated serum alkaline phosphatase, raises a suspicion of bile duct stone(s) in patients with gallstones. Cholangiography, either endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), is the best method for diagnosing bile duct stones. ERCP has the disadvantage of being invasive, and there is a risk of complications; while MRCP is costly and is not widely available. AIM: The objective of the present study was to evaluate the role of hepatobiliary nuclear scanning in diagnosing bile duct stones. METHODS: Twenty-five patients with suspected common bile duct (CBD) stones underwent hepatobiliary scintigraphy. The results of scintigraphy were compared with cholangiograms obtained by ERCP in 11 patients and MRCP in 14 patients, considering MRCP/ERCP as the 'gold standard'. RESULTS: Scintigraphy showed features suggestive of CBD stones in 11 of the 25 patients. The results of ERCP/MRCP confirmed that eight of them had stones. Scintigraphy showed no features of CBD stones in the remaining 14 patients. ERCP/MRCP showed CBD stones in two of these 14 patients. Thus, scintigraphy had a sensitivity of 80% and a specificity of 80%. CONCLUSION: We conclude that scintigraphy has good sensitivity and specificity in predicting CBD stones in patients with gallstone disease and a dilated CBD.     

The 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 ultrasound (US) in the diagnosis of choledocholithiasis in a large group of patients with bile duct stones confirmed at direct cholangiography. Also, to compare bile duct stones confirmed at direct cholangiography. Also, to compare bile duct stone characteristics using the three different investigations, endoscopic retrograde cholangiopancreatography (ERCP), MRCP and US. MATERIALS AND METHODS: 191 patients (M:F, 76:115; mean age, 66 years; range, 24-92 years) were investigated by direct cholangiography, MRCP and US. Their final diagnosis as determined at direct cholangiography were choledocholithiasis (n = 34), strictures (n = 47) and normal ducts (n = 110). The direct cholangiographic methods used for diagnosis of choledocholithiasis were ERCP (n = 29), intraoperative cholangiography (n = 3) and percutaneous transhepatic cholangiography (n = 2). The bile duct stone characteristics were compared using ERCP, MRCP and US in the 29 patients in whom stones were exclusively diagnosed by ERCP. RESULTS: Compared with the final diagnosis, MRCP had 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. US had a sensitivity, specificity and diagnostic accuracy of 38%, 100% and 89%, respectively, in the diagnosis of choledocholithiasis. ERCP diagnosed more stones and the stones were more proximally distributed within the bile duct at ERCP when compared with MRCP. CONCLUSION: MRCP has a high diagnostic accuracy (97%), similar to that at direct cholangiography, in the diagnosis of choloedocholithiasis. It has the potential to replace diagnostic ERCP and select patients with choledocholithiasis for therapeutic ERCP.     

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.     

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.     

核磁共振胰胆管水成像对腹腔镜胆囊切除术后综合征的诊断价值

目的：探讨磁共振胰胆管水成像(MRCP)对腹腔镜胆囊切除术(LC)后发生胆囊切除综合征(PCS)的诊断价值。方法：对比分析26例LC术后出现PCS和11例未出现PCS的患者的MRCP表现。结果：PCS组的胆总管扩张的发生率为65．38％(17／26)，对照组为18．18％(2／11)。PCS组的胆囊管残留过长的发生率为53．85％(14／26)，对照组为18．18％(2／11)。PCS组胆道结石的发生率为30．76％(8／26)，对照组为0％(0／11)。PCS组1例(3．84％)有胆总管狭窄，对照组没有。结论：对于诊断LC术后出现的PCS，MRCP是一种十分有效的检查方法。     

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.     

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。     

磁共振胰胆管成像诊断胰胆管合流异常的价值

目的 探讨磁共振胰胆管成像（MRCP）诊断胰胆管合流异常（APBDU）的价值。资料与方法 分析11例患者的MRCP、轴面T2WI及T1WI。测量共通管长度和胆总管宽度,观察APBDU的形式,以及胆管内有无结石和肿瘤等相关疾病。将观察结果与B超及内镜逆行性胰胆管造影（ERCP）检查和／或外科手术所见对照。结果 10例胆总管囊肿型APBDU包括胆管囊状扩张7例,梭形扩张3例;1例非囊肿型APBDU表现为胆总管轻度扩张。胆总管最大直径范围是12～90mm,平均34mm。APBDU的合流形式包括A型7例,B型4例,在MRCP图像测量的共通管长度范围是18～30mm,平均23mm。轴面T2WI显示胆总管或胰管突然蝌蚪或逗点样增粗5例。APBDU相关疾病包括胆囊／胆管结石6例,胆管肿瘤1例,胰腺炎5例。对7例切除的病变胆管和胆囊标本进行病理组织学检查,均有慢性炎症改变。结论 MRCP检查有助于发现和诊断APBDU,轴面T2WI和B超检查阴性结果不能完全排除本病。     

Diagnostic accuracy of multidetector-row computed tomography for common bile duct calculi: is it necessary to add non-contrast-enhanced images to contrast-enhanced images?

OBJECTIVE: To evaluate the diagnostic accuracy of 16-slice multidetector-row computed tomography (MDCT) for the detection of common bile duct (CBD) stones and to compare the diagnostic values between contrast-enhanced axial with multiplanar reformation (MPR) images and contrast-enhanced combined with non-contrast-enhanced axial images. MATERIALS AND METHODS: Fifty-four patients with suspected CBD stones underwent MDCT and endoscopic retrograde cholangiopancreatography (ERCP). Two radiologists independently evaluated contrast-enhanced axial with MPR images for the presence of CBD stones. Two weeks later, they performed a second review of contrast-enhanced and non-contrast-enhanced axial images. The ERCP was used as the criterion standard to confirm the presence of CBD stones. The McNemar test and receiver operating characteristic curve analysis were used to assess the differences in accuracy for detecting CBD stones. RESULTS: The ERCP identified bile duct stones in 27 patients and no stones in the other 27. Contrast-enhanced axial with MPR images had a sensitivity of 88.9%, specificity of 92.6%, and diagnostic accuracy of 90.7%. Contrast-enhanced combined with non-contrast-enhanced axial images had a sensitivity, specificity, and diagnostic accuracy of 88.9%. However, the difference between the 2 groups was not statistically significant. The areas under the receiver operating characteristic curve of the 2 groups were 0.929 and 0.905, respectively. CONCLUSIONS: The MDCT provides high accuracy in diagnosis for CBD stones. Adding non-contrast-enhanced images to contrast-enhanced images did not improve diagnostic accuracy, and therefore, additional non-contrast-enhanced images are not necessary.     

Role of magnetic resonance cholangiopancreatography in diagnosing choledochal cysts: Case series and review

AIM:To determine the merits of magnetic resonance cholangiopancreatography(MRCP) as the primary diagnostic test for choledochal cysts(CC’s).METHODS:Between 2009 and 2012,patients who underwent MRCP for perioperative diagnosis were identified.Demographic information,clinical characteristics,and radiographic findings were recorded.MRCP results were compared with intraoperative findings.A PubMed search identified studies published between 1996-2012,employing MRCP as the primary preoperative imaging and comparing results with either endoscopic retrograde cholangiopancreatography(ERCP) or operative findings.Detection rates for CC’s and abnormal pancreaticobiliary junction(APBJ) were calculated.In addition detection rates for clinically related biliary pathology like choledocholithiasis and cholangiocarcinomas in patients diagnosed with CC’s were also evaluated.RESULTS:Eight patients were identified with CC’s.Six patients out of them had typeⅣCC’s,1 had type I and 1 had a new variant of choledochal cyst with confluent dilatation of the common bile duct(CBD) and cystic duct.Seven patients had an APBJ and 3 of those had a long common-channel.Gallstones were found in 2 patients,1 had a CBD stone,and 1 pancreatic-duct stone was also detected.In all cases,MRCP successfully identified the type of CC’s,as well as APBJ with ductal stones.From analyzing the literature,we found that MRCP has 96%-100% detection rate for CC’s.Additionally,we found that the range for sensitivity,specificity,and diagnostic accuracy was 53%-100%,90%-100% and 56%-100% in diagnosing APBJ.MRCP’s detection rate was 100% for choledocholithiasis and 87% for cholangiocarcinomas with concurrent CC’s.CONCLUSION:After initial ultrasound and computed tomography scan,MRCP should be the next diagnostic test in both adult and pediatric patients.ERCP should be reserved for patients where therapeutic intervention is needed.     

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。     

MR cholangiopancreaticography and endoscopic retrograde cholangiopancreaticography in patients with suspected common bile duct stones

Purpose: To prospectively compare MR cholangiopancreaticography (MRCP) vs. endoscopic retrograde pancreaticography (ERCP) in patients with suspected common bile duct (CBD) stone disease.Material and Methods: Fifty consecutive patients with suspected CBD disease underwent MRCP and then ERCP within 12 h of each other. The result of the MRCP was blinded to the reader of the ERCP. The MRCP was done using a superconducting 1.0 T unit with a heavily T2-weighted breath-hold technique. The ERCP was done in the fluoroscopy suite by one of the clinicians and was evaluated by one of the radiologists who had not read the MRCP examinations.Results: There were 28 true-positives, 17 true-negatives, 1 false-positive, and 4 false-negatives. The sensitivity was 87.5% and the specificity 94.4%, respectively. The positive predictive value was 96.6% and the negative predictive value was 81.1%.Conclusion: MRCP was shown to be good enough to replace ERCP as a diagnostic method in patients with suspected CBD disease. MRCP is now our modality of choice after ultrasound in the diagnostic evaluation of these patients.     

Accuracy of magnetic resonance cholangiography compared to operative endoscopy in detecting biliary stones,a single center experience and review of literature

AIM: To compare diagnostic sensitivity, specificity and accuracy of magnetic resonance cholangiopancreatography (MRCP) without contrast medium and endoscopic ultrasound (EUS)/endoscopic retrograde cholangiopancreatography (ERCP) for biliary calculi.METHODS: From January 2012 to December 2013, two-hundred-sixty-three patients underwent MRCP at our institution, all MRCP procedure were performed with the same machinery. In two-hundred MRCP was done for pure hepatobiliary symptoms and these patients are the subjects of this study. Among these two-hundred patients, one-hundred-eleven (55.5%) underwent ERCP after MRCP. The retrospective study design consisted in the systematic revision of all images from MRCP and EUS/ERCP performed by two radiologist with a long experience in biliary imaging, an experienced endoscopist and a senior consultant in Hepatobiliopancreatic surgery. A false positive was defined an MRCP showing calculi with no findings at EUS/ERCP; a true positive was defined as a concordance between MRCP and EUS/ERCP findings; a false negative was defined as the absence of images suggesting calculi at MRCP with calculi localization/extraction at EUS/ERCP and a true negative was defined as a patient with no calculi at MRCP ad at least 6 mo of asymptomatic follow-up. Biliary tree dilatation was defined as a common bile duct diameter larger than 6 mm in a patient who had an in situ gallbladder. A third blinded radiologist who examined the MRCP and ERCP data reviewed misdiagnosed cases. Once obtained overall data on sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) we divided patients in two groups composed of those having concordant MRCP and EUS/ERCP (Group A, 72 patients) and those having discordant MRCP and EUS/ERCP (Group B, 20 patients). Dataset comparisons had been made by the Student’s t-test and χ² when appropriate.RESULTS: Two-hundred patients (91 men, 109 women, mean age 67.6 years, and range 25-98 years) underwent MRCP. All patients attended regular follow-up for at least 6 mo. Morbidity and mortality related to MRCP were null. MRCP was the only exam performed in 89 patients because it did show only calculi into the gallbladder with no signs of the presence of calculi into the bile duct and symptoms resolved within a few days or after colecistectomy. The patients remained asymptomatic for at least 6 mo, and we assumed they were true negatives. One hundred eleven (53 men, 58 women, mean age 69 years, range 25-98 years) underwent ERCP following MRCP. We did not find any difference between the two groups in terms of race, age, and sex. The overall median interval between MRCP and ERCP was 9 d. In detecting biliary stones MRCP Sensitivity was 77.4%, Specificity 100% and Accuracy 80.5% with a PPV of 100% and NPV of 85%; EUS showed 95% sensitivity, 100% specificity, 95.5% accuracy with 100% PPV and 57.1% NPV. The association of EUS with ERCP performed at 100% in all the evaluated parameters. When comparing the two groups, we did not find any statistically significant difference regarding age, sex, and race. Similarly, we did not find any differences regarding the number of extracted stones: 116 stones in Group A (median 2, range 1 to 9) and 27 in Group B (median 2, range 1 to 4). When we compared the size of the extracted stones we found that the patients in Group B had significantly smaller stones: 14.16 ± 8.11 mm in Group A and 5.15 ± 2.09 mm in Group B; 95% confidence interval = 5.89-12.13, standard error = 1.577; P < 0.05. We also found that in Group B there was a significantly higher incidence of stones smaller than 5 mm: 36 in Group A and 18 in Group B, P < 0.05.CONCLUSION: Major finding of the present study is that choledocholithiasis is still under-diagnosed in MRCP. Smaller stones (< 5 mm diameter) are hardly visualized on MRCP.     

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.     

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.     

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     

磁共振胰胆管造影诊断胆管系统结石

目的：评价磁共振胰胆管造影在胆管系统结石中的诊断价值。材料和方法：对１００例胆管系统结石的患者进行了ＭＲＣＰ检查,采用不屏气快速自旋回波（ＦＳＥ）序列重Ｔ２加权成像,并用呼吸触发、脂肪抑制和最大信号强度投影（ＭＩＰ）的三维重建方法。对ＭＲＣＰ的诊断结果与手术或临床作了对照分析。结果：本组病例均获得了诊断质量的ＭＲＣＰ图像;１００例胆道结石的患者共有１５８处结石：肝内胆管结石２６例次,胆囊结石５６例次,总胆管结石７３例次和总肝管结石３例次。胆管系统结石的主要ＭＲＣＰ表现为：圆形或卵圆形信号缺失（充盈缺损）;倒杯口征;靶征;铸型样结石。ＭＲＣＰ结合原始图像对胆管系统结石诊断总检出率为９０％,而ＭＲＣＰ对胆管系统结石诊断部检出率为８２％两者比较（Ｐ〈０．０５）。结论：ＭＲＣＰ结合原始图像对胆管系统结石的诊断有较高的准     

Differentiation of extrahepatic bile duct cholangiocarcinoma from benign stricture: findings at MRCP versus ERCP

PURPOSE: To retrospectively evaluate criteria for differentiating extrahepatic bile duct cholangiocarcinoma from benign cause of stricture at magnetic resonance cholangiopancreatography (MRCP) and to compare diagnostic accuracy with this modality versus endoscopic retrograde cholangiopancreatography (ERCP). MATERIALS AND METHODS: MRCP and ERCP images in 50 patients (27 with cholangiocarcinoma [18 men, nine women; mean age, 58 years] and 23 with benign cause of stricture [13 men, 10 women; mean age, 60 years]) were retrospectively reviewed to assess the appearance of bile duct strictures. Final diagnosis was based on surgical or biopsy findings. Strictures were described according to their imaging appearance (irregular or smooth margins, asymmetric or symmetric narrowing, abrupt narrowing or gradual tapering, and presence or absence of double-duct sign). Sensitivity, specificity, and accuracy of MRCP and ERCP were calculated by using ratings of confidence in image-based diagnosis. Lengths of stricture were electronically measured and compared by using the Student t test. RESULTS: Among cholangiographic criteria for malignant biliary stricture, irregular margins and asymmetric narrowing were more common in cholangiocarcinomas (24 [89%] of 27 patients) than in benign strictures (six [26%] and eight [35%] of 23 patients, respectively). Sensitivity, specificity, and accuracy of the two methods for differentiation of malignant from benign causes of biliary stricture were 81% (22 of 27), 70% (16 of 23), and 76% (38 of 50), respectively, for MRCP and 74% (20 of 27), 70% (16 of 23), and 72% (36 of 50), respectively, for ERCP. Mean length (+/- standard deviation) of cholangiocarcinomas was 30.0 mm +/- 8.5, and that of benign strictures was 13.6 mm +/- 9.1 (P <.001). CONCLUSION: Accuracy of MRCP is comparable with that of ERCP. Regardless of modality, a lengthy segment of extrahepatic bile duct stricture with irregular margin and asymmetric narrowing suggests cholangiocarcinoma, and a short segment with regular margin and symmetric narrowing suggests benign cause.     

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.     

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。