Secretin-stimulated MRCP

Secretin-stimulated magnetic resonance cholangiopancreatography not only facilitate the depiction of anatomic variations or morphologic changes of the pancreatic duct in the normal and diseased pancreas but also help assessing functional abnormalities of the exocrine pancreas. In this article, we illustrate findings of normal pancreas and various pancreatic diseases on magnetic resonance cholangiopancreatography after secretin stimulation.     

Fentanyl-augmented MRCP

Background Drugs such as secretin and morphine have been used to augment the visualization of magnetic resonance cholangiopancreatography (MRCP). This study investigated the effectiveness of intravenous administration of a synthetic opioid, fentanyl, in improving the MRCP image quality. Methods Thirty consecutive patients with a provisional diagnosis of benign biliary and/or pancreatic disease underwent MRCP. Coronal single-shot fast spin-echo heavily T2-weighted dynamic MRCP images were generated before and at every minute for 10 min after intravenous administration of fentanyl citrate at a dose of 1.0 μg/kg. Pre- and postinjection images were compared and analyzed qualitatively and quantitatively. Results Qualitatively, visualization of intrahepatic bile ducts, common bile duct, and main pancreatic duct improved after fentanyl injection in five (16%), 11 (37%), and 19 (63%) patients, respectively. The pancreatobiliary junction and common channel were visualized better after fentanyl injection in eight of the 18 patients (44%). Quantitatively, signal intensity and diameters of the intrahepatic ducts, common bile duct, and main pancreatic duct measured at corresponding points on pre- and postinjection images showed an increase above preinjection values in 28 (93%), 27 (90%), and 21 (70%) and in 18 (60%), 26 (86%), and 22 (73%), respectively, and these changes were highly significant at all sites (p < 0.001). Conclusions Intravenous administration of fentanyl before MRCP improves qualitative and quantitative visualization of the ductal system anatomy that may be of value in clinical diagnosis and management.     

Collateral branches IPMTs: secretin-enhanced MRCP

Recently, the fantastic evolution of imaging modalities (especially MR, MDCT, EUS) has raised many issues regarding the correct classification of smaller and smaller lesions, their preoperative evaluations, and indications of most appropriate treatment. However, it is still debated which technique should be employed for the diagnosis and the follow-up of intraductal papillary mucinous tumours (IPMTs). Despite the superb spatial resolution of MDCT, nowadays most of the authors agree on considering MR with magnetic resonance cholangiopancreatography (MRCP) the imaging modality of choice in studying IPMTs. In particular, MRCP is rapid, non-invasive, and accurate in detecting, localizing, and correctly classifying IPMT. The diagnostic performance of MRCP is even improved after the introduction of secretin stimulation. In fact, dynamic MRCP studies after secretin administration, besides facilitating the depiction of the structural characteristics of the lesions, make easier the detection of the communicating duct of branch duct IPMTs with the main pancreatic duct, especially if the newest high resolution 3D heavily T2-weighted sequences are utilized. Secretin stimulation is also useful in the demonstration of early changes of associated chronic pancreatitis. Consequently, we believe that secretin-enhanced MRCP is the most suitable imaging modality in the diagnosis and follow-up of IPMTs of the collateral branches.     

磁共振胰胆管成像与内镜下逆行胰胆管造影对急性胰腺炎的诊断价值

目的:了解磁共振胰胆管成像与内镜下逆行胰胆管造影对急性胆源性胰腺炎的诊断价值。方法:对110例急性胰腺炎患者临床资料与磁共振胰胆管成像及内镜下逆行胰胆管造影检查结果进行综合对比分析。结果:磁共振胰胆管成像对急性胆源性胰腺炎诊断的准确率为89.3%,内镜下逆行胰胆管造影的准确率为92%,二者比较,差异无统计学意义;磁共振胰胆管成像对急性胰腺炎的灵敏度为89.3%,特异度为77.1%,约登指数为0.664;内镜下逆行胰胆管造影对急性胆源性胰腺炎的灵敏度为92%,特异度为82.9%,约登指数为0.749。结论:磁共振胰胆管成像尚不能取代内镜下逆行胰胆管造影诊断胰胆系疾病,特别是在明确胆源性胰腺炎病因方面的作用,二者可互补从而提高急性胰腺炎的诊断水平。     

Efficacy of multidirection MRCP

Pancreatobiliary system has complex and thin structure except for gallbladder, thereby MRCP having lower spatial resolution gives sufficient information compared with the direct cholangiopancreatography. Multidirection MRCP using HASTE sequence obtains the data in plane to compensate the lower spatial resolution, thus high detectability of all over pancreatobiliary system is performed in a few minutes. This technique overcomes the demerits pointed by former investigators and gives sufficient information to diagnose the pancreatobiliary diseases.     

Biliary complications after orthotopic liver transplantation: MRCP findings

Orthotopic liver transplantation is a widely accepted treatment for end-stage liver disease and selected cases of hepatocellular carcinoma. Despite surgical progresses, biliary complications after transplantation remain a serious cause of morbidity, mortality, and graft dysfunction or failure in recipients. Early complications occur within a few weeks after transplantation and are mainly represented by bile leakage. Late complications, which become evident from 3 months to years, include strictures, stones, intraductal debris or sludge formation, kinking and ampullary dysfunction. Donor-to-recipient common bile duct disproportion has been reported as a borderline condition. Diagnosis is challenging because of the low specificity of clinical and biologic findings. Sonography does not provide projectional images of the biliary tract or direct evaluation of the anastomoses. Moreover, direct cholangiographic procedures have an unacceptable rate of complications to be used in patients with low clinical suspicion. Magnetic resonance cholangiography is a safe and accurate tool, playing an increasing role in the diagnosis and management of biliary complications. Heavily T2-weighted images provide panoramic, detailed evaluation of the biliary tract, showing biliary complications as a variable combination of bile duct dilatation, strictures, filling defects, fluid collections and peculiar morphologic changes, as described in this paper.     

MRCP of congenital pancreaticobiliary malformation

Background Congenital pancreaticobiliary malformations are sometimes associated with acute or chronic pancreatitis and biliary carcinoma. Currently, magnetic resonance cholangiopancreatography (MRCP) is one of the first choices for investigating and diagnosing pancreaticobiliary diseases noninvasively. We compared the accuracy of conventional MRCP and endoscopic retrograde cholangiopancreatography (ERCP) in making the diagnosis of congenital pancreaticobiliary malformations. Methods In patients with pancreas divisum (n = 17), pancreaticobiliary maljunction (n = 12), choledochocele (n = 2), and annular pancreas (n = 1) who underwent ERCP and MRCP, the diagnostic accuracy and findings on MRCP were compared with those on ERCP. Results Of the 32 patients with congenital pancreaticobiliary malformations diagnosed on ERCP, 23 (72%) presented the same diagnosis on MRCP. Complete pancreas divisum was diagnosed in 73% on MRCP based on the finding of a dominant dorsal pancreatic duct crossing the lower bile duct and emptying into the duodenum without communicating with the ventral pancreatic duct. Pancreaticobiliary maljunction was diagnosed in 75% on MRCP based on the finding of an anomalous union between the common bile duct and the pancreatic duct and the existence of a long common channel. Conclusions Conventional MRCP is a useful, noninvasive tool for diagnosing congenital pancreaticobiliary malformations; and the diagnostic accuracy can be increased with three-dimensional MRCP or dynamic MRCP with secretin stimulation.     

MRCP时联合应用MR平扫及增强扫描的价值

目的评价MR平扫及动态增强扫描联合应用在MRCP诊断胰胆管疾病中的补充价值.方法回顾分析64例胰胆管疾病病例的MRI表现,由两名有MR诊断经验的影像医生在无临床资料的情况下分为MRCP、MRCP与MR平扫结合、MRCP结合MR平扫及动态增强三步阅片,与手术、病理结果或临床综合诊断对照后进行对比分析.结果第一、二步骤间定性诊断准确率、敏感度及特异度分别提高17.2%、14.7%及20%,差异显著(χ2=6.02,P＜0.05),而第二、三步骤间差异不显著(χ2=1.74,P＞0.05),但诊断准确率及确认度三步骤间均有显著差异.结论 MRCP应与MR平扫及动态增强扫描相结合,MR平扫与MRI动态增强扫描必要且有价值.