磁共振成像在胰胆管疾病中的应用

目的：介绍用磁共振检查胰胆管疾病的四种扫描序列,并评价它们的作用和局限性。材料和方法：对５２例疑有胰胆管疾病的患者行两种Ｔ２加权和两种ＭＲＣＰ序列检查;横断位ＨＡＳＴＥ序列、冠状位ＴｒｕｅＦＩＳＰ序列、ＴｒｕｅＳＥ ＭＲＣＰ序列和ＨＡＳＴＥ ＭＲＣＰ序列。４２例经ＥＲＣＰ或手术病理证实,其检查结果与ＥＲＣＰ或手术对照。结果：所有图像的质量均达到了能够诊断的要求。四种扫描序列均显示了所有扩张的胰胆管,胆管结石定性的准确性分别为８７．５％、９１．７％、８７．５％和９５．８％,对肿瘤的定性准确性分别为８２．４％、７６．５％、６４．７％和７０．６％,结合所有序列对结石定性的准确性为１００％,对肿瘤的定性准确性为８８．２％。结论：上述四种扫描序列对显示胆胰管疾病各有其优点,结合应用可提高胰胆管疾病检出率和作出更准确的定性     

True FISP序列在胰胆管疾病的应用

评价ＴｒｕｅＦＩＳＰ序列在胰胆管疾病中的应用价值与限度。材料与方法,对９８例怀疑胰胆管疾病的患者和１２例正常志愿者做ＴｒｕｅＦＩＳＰ与ＡＳＴＥ－ＭＲＣＰ扫描。结果ＴｒｕｅＦＩＳＰ像、ＭＲＣＰ断层像和ＭＲＣＰＭＩＰ像显示胰胆管扩张的准确性均达到了１００％,对病变定位的准确率分别为９４．４％、８３．３％;对胆管结石定性的准确率（特异性）分别为７３．３％（８８．１％）、９３．３％（９２．９％）和６６．７     

MR cholangiopancreatography in choledochal cysts

PURPOSE: To assess the value of MR cholangiopancreatography (MRCP) in the diagnosis and preoperative evaluation of choledochal cysts. MATERIAL AND METHODS: Five patients (aged between 6 days and 28 years) were investigated by MRCP, referred for ultrasonographic detection of a bile duct dilatation or a cystic structure, of antenatal diagnosis (1 case), for jaundice or abdominal pain (3 cases) or in late follow-up of a choledochal cyst surgery. Two endoscopic-ultrasonographic studies were performed. The five patients underwent surgery without preoperative biliary cholangiography. MRCP was performed using a HASTE sequence in frontal, oblique, axial planes (1,5 Tesla MR unit). RESULTS: MRCP allowed to confirm choledochal cyst, helps to specify the anatomical type (2 type I, 3 type II), detects choledocholithiasis (3 cases). Anatomic correlation was perfect. MRCP allowed to exclude gastrointestinal duplication. Anomalous junction of the pancreaticobiliary duct was found in one case. CONCLUSION: MRCP diagnoses choledochal cysts, specifies type, helps surgery and can avoid endoscopic retrograde cholangiography or endoscopic sonographic examinations especially for children. It may find an anomalous junction of the pancreaticobiliary duct.     

Congenital anomalies and normal variants of the pancreaticobiliary tract and the pancreas in adults: part 1, Biliary tract

OBJECTIVE: The purpose of this article is to highlight the imaging features of congenital anomalies and normal variants of the biliary tract with contemporary imaging techniques such as MR cholangiopancreatography (MRCP), MRI, and helical CT. CONCLUSION: Recognizing findings of congenital anomalies and normal variants of the biliary tract at MRCP, MRI, and helical CT, and knowledge of the clinical significance of each entity, are important for establishing a correct diagnosis and in guiding appropriate clinical management.     

口服枸橼酸铁铵在梗阻性黄疸MRCP检查中的应用价值评估

目的评价采用枸橼酸铁铵作为胃肠道口服阴性对比剂对提高梗阻性黄疸患者磁共振胰胆管成像(MRCP)检查质量的作用。方法对50例临床怀疑梗阻性黄疸的患者行MRCP检查,将患者随机分为2组:试验组25例患者,在检查前30min时口服枸橼酸铁铵冲剂;对照组25例患者,不服用任何对比剂。观察患者对口服对比剂的耐受性;对所有患者进行冠状位厚层的半傅立叶单次激励快速自旋回波序列(HASTE)和呼吸触发的3D快速自旋回波序列(RT-3D-TSE)扫描。由2位放射科医师单盲阅片,对2组患者MRCP图像的对比效果和图像质量作评估和分级。结果所有患者对枸橼酸铁铵溶液都有很好的耐受性。口服枸橼酸铁铵溶液后所有试验组MRCP图像上的胃肠道高信号都有很大程度的抑制,对比效果和图像质量有明显改善,胆道解剖结构显示的清晰性明显提高。结论口服枸橼酸铁铵溶液作为安全的胃肠道阴性对比剂在梗阻性黄疸患者的MRCP检查中可以有效降低胃肠道高信号所造成的影响及假象,改善胆道系统的显示情况,便于诊断。     

Pancreaticobiliary ductal system: value of half-Fourier rapid acquisition with relaxation enhancement MR cholangiopancreatography for postoperative evaluation

PURPOSE: To assess the usefulness of half-Fourier rapid acquisition with relaxation enhancement (RARE) magnetic resonance cholangiopancreatography (MRCP) for evaluation of postoperative changes in the pancreaticobiliary ductal system. MATERIALS AND METHODS: The study included 34 patients (20 men, 14 women; mean age, 65.5 years) who underwent surgery of the pancreaticobiliary ductal system. Half-Fourier RARE MRCP images were obtained after surgery. Qualitative evaluation included ratings by two observers for depiction of postoperative anatomy and for artifacts, as well as analysis of postoperative complications. Direct cholangiographic, computed tomographic, and ultrasonographic findings and 6-month follow-up results were the reference standard. Sensitivity, specificity, and accuracy were calculated for the evaluation of postsurgical complications seen at half-Fourier RARE MRCP. RESULTS: The sensitivity, specificity, and accuracy of MRCP for the evaluation of postsurgical complications were each 100% for ductal dilatation; 100%, 87%, and 89%, respectively, for choledochoenteric anastomotic stricture; 100%, 86%, and 87%, respectively, for pancreaticoenteric anastomotic stricture; 100% each for intraductal stones and anastomotic leakage; and 80%, 100%, and 94%, respectively, for cholangitis. CONCLUSION: Half-Fourier RARE MRCP is a reliable imaging technique for the evaluation of anatomy and of complications associated with a surgically altered pancreaticobiliary ductal system.     

磁共振胰胆管成像在胰胆管疾病诊断中的应用价值

目的探讨磁共振胰胆管成像（MRCP）在胰胆管疾病诊断中的临床应用价值。方法采用重T2加权多次激发对100例临床拟诊胆道梗阻的患者进行MRCP检查,并经手术病理或其他影像学或临床资料证实。恶性梗阻28例,其中胰头癌9例,壶腹癌6例,胆管癌10例,原发性肝细胞癌直接侵犯3例;良性梗阻72例,其中胆总管结石33例,胆囊切除术后狭窄5例,胆囊炎或结石26例,慢性胰腺炎4例,先天性胆总管囊肿2例,硬化性胆管炎2例。结果 MRCP较清晰地显示了各种胰胆管疾病的部位和形态。本组定位诊断准确率为85%。MRCP的诊断敏感性为75%,特异性为83%,准确性为81%,阳性预测值为85%,阴性预测值为93%。结论 MRCP对于胆道梗阻性病变的定位较为准确,结合MRI平扫及资源像,定性诊断也有一定的特异性,是一种安全、无创的检查手段,能为临床诊治提供可靠依据。     

Congenital anomalies and variations of the bile and pancreatic ducts: magnetic resonance cholangiopancreatography findings, epidemiology and clinical significance

Purpose

The objective of this paper is to document the magnetic resonance cholangiopancreatography (MRCP) findings and the epidemiology of congenital anomalies and variations of the bile and pancreatic ducts and to discuss their clinical significance.

Materials and methods

Three-hundred and fifty patients of both sexes (150 females, 200 males, age range 0–76 years, average age 38 years) underwent MRCP for clinically suspected lithiasic, neoplastic or inflammatory disease of the bile and pancreatic ducts. Patients were imaged with a 1.5-T superconductive magnet (Magnetom Vision, Siemens, Erlangen, Germany), a four-channel phased-array body coil, breath-hold technique, with multislice T2-weighted half-Fourier acquisition single-shot turbo spin echo (HASTE), MIP reconstructions, and a single-shot T2-weighted turbo-spin-echo sequence rapid acquisition with relaxation enhancement (RARE) with different slice thicknesses. Studies in oncological patients were completed with fat saturation 3D T1 gradient-echo sequences during the intravenous injection of gadolinium diethylene triamine pentaacetate acid (DTPA) (0.2 ml/kg).

Results

MRCP demonstrated recurrent and therefore normal bile and pancreatic ducts in 57% of patients. In the remaining 42.3%, it documented anatomical variants (41%) and congenital anomalies (1.3%). Variants of the intrahepatic bile duct were seen in 21% of cases: crossover anomaly (6.7%), anterior branch of the right hepatic duct draining the IV and VII segments that flow together with the left bile duct (3.1%) and anterior and posterior branches of the right hepatic duct that flow together with the common hepatic duct (3.3%). Variants of the extrahepatic bile ducts were present in 8.8% of patients: low insertion of the cystic duct into the common hepatic duct (4.5%), emptying of the cystic duct into the right hepatic duct (2.7%) and a second-order large branch draining into the cystic duct (1.6%). MRCP identified a double gall bladder in 3% of patients and anatomical variants of the biliopancreatic system in 8.2%: pancreas divisum (5.2%) and a long sphincter of Oddi (3%). Finally, congenital anomalies were diagnosed in 1.3% of cases: bile duct cysts (0.3%), atresia of the bile ducts (0.3%) and multiple biliary hamartomatosis (0.7%).

Conclusions

The congenital anomalies and anatomical variants of the bile and pancreatic ducts present a complex spectrum of frequent alterations, which are worthy of attention in both the clinical and surgical settings and are readily identified by MRCP.     

MR cholangiopancreatography using HASTE sequences.

AIM: The aim of this pictorial review is to describe applications of cholangiopancreatography (MRCP) using half-Fourier (HASTE) MR sequences. MATERIALS AND METHODS: 350 patients were imaged over a four-year period with a 1.54 Tesla Siemens Vision scanner and a phased array body coil. The HASTE MR sequence was applied in multiple planes with an acquisition time of 13 seconds allowing breath hold techniques. In addition, a single-shot technique provided single slice acquisitions with a thickness of 20 mm. A chemical fat suppression algorithm reduced intra-abdominal MR high signal. RESULTS: HASTE MRCP accurately determines the presence of level of biliary obstruction in up to 97% of patients. Common bile duct stones are detected with a sensitivity of 93%. Acute cholecystitis is depicted on HASTE MR as pericholecystic high signal in 41/45 (91%) patients and gall stones are detected with a 93% sensitivity. CONCLUSION: HASTE MRCP offers a non-invasive, rapid imaging method to evaluate the gallbladder, common bile duct and pancreas. Its multi-planar, fluid sensitive capabilities are of particular value in detecting common bile duct stones and acute cholecystitis.     

磁共振胰胆管造影在肝外胆道梗阻性疾病中的应用价值分析

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 2 9例肝外胆管梗阻性疾病 (肝外胆管结石 9例 ,恶性胆管梗阻 18例 ,胆囊周围淋巴结反应性增生 1例 ,胆囊结石 1例 )进行MRCP检查 ,并与术后病理结果或临床综合诊断对照分析。MRCP采用屏气单次激发半数傅立叶变换的TSE序列 (HASTE) ,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 2 9例MRCP检查均一次成功 ,2 7例胆胰管显示满意。MRCP对肝外胆管梗阻性疾病的定位诊断率为 10 0 % ,定性诊断率为 79.3 %。结论　MRCP检查成功率高 ,对肝外胆管梗阻的定位诊断准确 ,结合原始图像和常规MRI扫描 ,对肝外胆管结石和恶性胆管梗阻的定性诊断也有较高的准确性     

Magnetic resonance cholangiopancreatography in the evaluation of pancreatic duct pathology

MR cholangiopancreatography (MRCP) may replace direct pancreatography in the evaluation of the pancreatic duct. The aim of this pictorial review is to demonstrate the usefulness of MRCP in the evaluation of pancreatic duct pathology. The examination technique included coronal, sagittal and axial breath-hold HASTE 2D imaging using a body phase array coil. We present the diagnostic features on MRCP of a variety of benign and malignant disorders of the pancreatic duct, and conclude that MRCP is a suitable method for imaging the pancreatic duct system.     

MR cholangiopancreatography: comparison of images obtained with 1.0 and 1.5 Tesla units

OBJECTIVE: To compare the image quality and visualization obtained in MR cholangiopancreatography (MRCP) using different high-field strength (1.0 vs. 1.5 Tesla) MR units and to assess the effect of field strength on MRCP. MATERIALS AND METHODS: This study population included 10 healthy volunteers and 37 patients suspected of having pancreatobiliary diseases. MRCP images were obtained using two MR units with different high-field strengths (1.0 and 1.5 Tesla), with half-Fourier acquisition single-shot turbo spin-echo (HASTE) and rapid acquisition by relaxation enhancement (RARE) sequences. The image quality and visualization of each portion of the pancreatobiliary system were graded and recorded using a four-point scale. Additionally, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured. RESULTS: The SNR and CNR in HASTE sequences acquired with the 1.5 Tesla (T) unit were significantly higher than those acquired with the 1.0 T unit (p=0.001). In qualitative analysis, there were no statistically significant differences in image quality or visualization of the ducts in either HASTE or RARE sequences between 1.0 T and 1.5 T. CONCLUSION: Our study showed that visual image quality provided by MRCP was equivalent at 1.0 and 1.5 T.     

单次屏气超快速MRI在胆系梗阻性疾患诊断中的应用

目的 ⑴评估单次屏气半傅立叶采集单次激发快速自旋回波磁共振胆胰管造影（ＨＡＳＴＥ－ＭＲＣＰ）对于胆系梗阻性疾患胆胰管的显示情况及对疾病诊断的准确性。⑵评估单次屏气ＨＡＳＴＥ－ＭＲＣＰ与真稳态进动快速成像（Ｔrue ＦＩＳＰ）Ｔ２＊Ｗ１相结合在胆系梗阻性疾患诊断中的应用价值。方法 １３２例胆系梗阻患者术前行ＭＲ检查（Ｓiemens１．５Ｔ Ｍagnetojm Ｖision）。所有扫描序列均采用单次屏气快速扫描并配以体部相控     

MR cholangiopancreatography

In summary, over the past decade, MRCP has evolved not only as a feasible means of noninvasively evaluating the pancreaticobiliary tract but also as a technique with documented clinical utility. With the evolution of MRCP, there has been, by necessity, an evolution of ERCP. In fact, at some institutions MRCP has replaced diagnostic ERCP such that ERCP is reserved primarily for therapeutic interventions. When MRCP is performed in conjunction with abdominal MR and MRA, a comprehensive examination results that permits evaluation of the solid organs and vessels of the abdomen as well as the ductal systems.     

HASTE磁共振胰胆管成像诊断胆道恶性梗阻病变的价值

目的探讨HASTE磁共振胰胆管造影在胆道恶性梗阻病变诊断中的应用价值。方法分析经手术病理或活检证实的43例胆道恶性梗阻病变患者的HASTE-MRCP影像表现。结果HASTE-MRCP诊断胆道恶性梗阻,其定位诊断符合率为100%,定性诊断符合率为75%。结论HASTE-MRCP在胆道恶性梗阻性病变的诊断中具有良好的应用价值。     

磁共振胰胆管造影对梗阻性黄疸诊断价值

目的:探讨研究MRCP对梗阻性黄疸的诊断价值。方法:对43例经手术病理证实的结石、良性狭窄、壶腹癌、胰头癌、胆管癌的梗阻性黄疸患者进行MRCP检查。结果:结石11例,良性狭窄2例,先天性胆总管囊肿1例,壶腹癌5例,胰头癌7例,胆管癌15例,胆囊癌2例。MRCP能清晰地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,其检出率和定位率为100%,定性诊断率为98%。结论:MRCP对梗阻性黄疸定位、定性诊断准确,特别对结石的诊断,结合原始图像有特异性,能清楚显示梗阻部位、梗阻原因、病变形态、病变与周围关系及病变性质。     

MRCP imaging at 3.0 T vs. 1.5 T: preliminary experience in healthy volunteers

PURPOSE: To evaluate the impact of magnetic resonance cholangiopancreatography (MRCP) imaging at 1.5T and 3.0T on image quality. MATERIALS AND METHODS: Fourteen volunteers were examined at both 1.5T and 3.0T using MRCP imaging performed with a breath-held two-dimensional (2D) half-Fourier acquired single-shot turbo spin-echo (HASTE) thick-slab sequence, a free-breathing navigator-triggered three-dimensional (3D) turbo spin-echo (TSE) sequence with prospective acquisition correction, and a heavily T2-weighted (T2W) sequence with breath-held multislice HASTE. All images were scored for visualization of the biliary and pancreatic ducts, severity of artifacts, image noise, and overall image quality. RESULTS: MRCP imaging at 3.0T yielded a significant improvement in overall image quality compared to 1.5T. We found a trend for superior visualization of the biliary and pancreatic ducts at 3.0T. Heavily T2W imaging with thin sections (1.4 mm) at 3.0T provided diagnostic images and better visualization of the biliary and pancreatic ducts than heavily T2W imaging with standard sections (2.8 mm) at 3.0T. CONCLUSION: Our experience suggests that MRCP imaging at 3.0T has the potential to provide excellent images. High-resolution heavily T2W imaging with a small voxel size (1.3 x 1.3 x 1.4 mm) at 3.0T can provide diagnostic images and allow evaluation of small pathologies of the bile and pancreatic ducts, which 1.5T MRI cannot sufficiently visualize.     

How reliable is MRCP with an SS-FSE sequence at 3.0 T: comparison between SS-FSE BH and 3D-FSE BH ASSET sequences

PurposeThe purpose of the present study was to evaluate the visibility and the image quality of the biliary and pancreatic duct system on magnetic resonance cholangiopancreatography (MRCP) images based on two breath-hold (BH) methods using array spatial sensitivity technique: a single-shot fast spin-echo (SS-FSE) sequence and a three-dimensional single slab fast spin-echo (3D-FSE) sequence.Materials and methodsIn the present prospective comparative study, 47 patients (22 male and 25 female, mean age=50 years, age range=22–82 years) that were referred for MRCP during a 12-month period are included. All of them were referred with suspected pancreaticobiliary disease. All patients underwent MRCP with both a SS-FSE BH sequence and a 3D-FSE BH sequence. Qualitative evaluation regarding the depiction of three segments of the pancreaticobiliary tree and the frequency of artifacts was performed. Two radiologists graded each sequence of the obtained studies in a blinded fashion. Quantitative evaluation including calculation of relative signal intensity (rSI) and relative contrast (RC) ratios at seven segments of the pancreaticobiliary tree between fluid-filled ductal structures and organ parenchyma at the same ductal segments was performed. In order to evaluate the parameters' differences of the two sequences, either in qualitative or in quantitative analysis, the Wilcoxon paired signed-rank test was performed.ResultsOn quantitative evaluation, both rSI and RC ratios of all segments of the pancreaticobiliary tree at SS-FSE BH sequence were higher than those at 3D-FSE BH sequences. This finding was statistically significant (P< .01). On qualitative evaluation, the two radiologists found intrahepatic ducts and pancreatic ducts to be better visualized with SS-FSE BH than with 3D-FSE BH sequence. This finding was statistically significant (P< .02). One of them found extrahepatic ducts to be significantly better visualized with SS-FSE BH sequence. Moreover, the frequency of artifacts was lower in the SS-FSE sequence, a finding that was of statistical significance. Interobserver agreement analysis found at least substantial agreement (κ>0.60) between the two radiologists.ConclusionThe SS-FSE sequence is performed faster and significantly improves image quality; thus, it should be included into the routine MRCP sequence protocol at 3.0 T. Furthermore, we recommended SS-FSE BH MRCP examination to be applied to uncooperative patients or patients in emergency because of its short acquisition time (1 s).     

Respiratory-triggered MRCP applying parallel acquisition techniques

PURPOSE: To evaluate the influence of parallel imaging on the image quality of respiratory triggered magnetic resonance cholangiopancreatography (MRCP). MATERIALS AND METHODS: A total of 30 consecutive patients underwent MRCP applying a respiratory triggered T2-weighted (T2w) turbo spin-echo (TSE) sequence without and with parallel imaging (acceleration factor of 2). Acquisition times of both sequences were recorded. Quantitative evaluation included measurement of a contour sharpness index of two segments of the pancreaticobiliary tree as well as calculation of the relative contrast between ductal structures and organ parenchyma at four different segments. The qualitative evaluation was performed by two independent radiologists who graded overall image quality, depiction of eight segments of the pancreaticobiliary tree, and the frequency of artifacts. RESULTS: The application of parallel imaging significantly (P<0.05) reduced the acquisition time of the respiratory triggered MRCP sequence by 37.7% (six minutes and two seconds+/-one minute and 26 seconds vs. three minutes and 46 seconds+/-58 seconds). The quantitative and qualitative evaluation revealed no statistically significant differences between the two sequences (P>0.05). The frequency of artifacts was at the same level for both sequences as well. CONCLUSION: The application of parallel imaging for respiratory triggered MRCP significantly reduces the acquisition time without relevant influence on image quality.     

Clinical evaluation of further-developed MRCP sequences in comparison with standard MRCP sequences

The purpose of this study was the comparison of technically improved single-shot magnetic resonance cholangiopancreatography (MRCP) sequences with standard single-shot rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquired single-shot turbo spin-echo (HASTE) sequences in evaluating the normal and abnormal biliary duct system. The bile duct system of 45 patients was prospectively investigated on a 1.5-T MRI system. The investigation was performed with RARE and HASTE MR cholangiography sequences with standard and high spatial resolutions, and with a delayed-echo half-Fourier RARE (HASTE) sequence. Findings of the improved MRCP sequences were compared with the standard MRCP sequences. The level of confidence in assessing the diagnosis was divided into five groups. The Wilcoxon signed-rank test at a level of p<0.05 was applied. In 15 patients no pathology was found. The MRCP showed stenoses of the bile duct system in 10 patients and choledocholithiasis and cholecystolithiasis in 16 patients. In 12 patients a dilatation of the bile duct system was found. Comparison of the low- and high spatial resolution sequences and the short and long TE times of the half-Fourier RARE (HASTE) sequence revealed no statistically significant differences regarding accuracy of the examination. The diagnostic confidence level in assessing normal or pathological findings for the high-resolution RARE and half-Fourier RARE (HASTE) was significantly better than for the standard sequences. For the delayed-echo half-Fourier RARE (HASTE) sequence no statistically significant difference was seen. The high-resolution RARE and half-Fourier RARE (HASTE) sequences had a higher confidence level, but there was no significant difference in diagnosis in terms of detection and assessment of pathological changes in the biliary duct system compared with standard sequences.