Dynamic MR pancreatography after secretin administration: image quality and diagnostic accuracy

OBJECTIVE: The objective of our study was to assess the improvement of image quality and diagnostic accuracy of secretin-enhanced MR pancreatography compared with conventional MR pancreatography. SUBJECTS AND METHODS: Ninety-five patients were studied with a 1.5-T scanner using a T2-weighted single-slice fast spin-echo sequence. Image quality and diameter of the head, body, and tail portion of the pancreatic main duct, the accessory duct, and the side branches were assessed before and after IV administration of secretin. Diagnoses before and after secretin administration were evaluated in a blinded fashion and correlated to the final diagnoses based on endoscopic retrograde cholangiopancreatography (ERCP), intraoperative results, and clinical follow-up as the reference standard. RESULTS: In patients with a normal pancreatic duct, the visualization of all portions of the main pancreatic duct and the accessory duct was significantly improved with dynamic MR pancreatography (p < or = 0.001). In patients with chronic pancreatitis, the visualization of the main duct was also significantly improved with dynamic MR pancreatography (p < or = 0.05). However, the visualization of the minor duct and the side branches was significantly improved only in patients showing no ductal stricture (p < or = 0.05), compared with those with ductal stricture (not significant). The overall sensitivity for the detection of chronic pancreatitis increased from 77% to 89% using secretin-enhanced MR pancreatography. A pancreas divisum was found in eight patients before and 13 patients after secretin administration. The overall negative predictive value of MR pancreatography increased from 84% to 98% after secretin administration. CONCLUSION: Improvement in image quality after secretin stimulation increases the diagnostic value of MR pancreatography in patients with a normal or nondilated main pancreatic duct and may obviate invasive procedures such as ERCP.     

Idiopathic chronic pancreatitis in children: MR cholangiopancreatography after secretin administration

PURPOSE: To assess the accuracy of dynamic magnetic resonance (MR) cholangiopancreatography after secretin administration in detecting pancreatic duct abnormalities typical of early-onset idiopathic chronic pancreatitis in children with recurrent episodes of idiopathic acute pancreatitis. MATERIALS AND METHODS: Fifteen children (mean age, 11.3 years; range, 6-17 years) with at least three recurrent episodes of idiopathic acute pancreatitis prospectively underwent MR cholangiopancreatography before and after secretin administration. Image analysis included visualization of side branches, ductal narrowing, endoluminal filling defects, irregular ductal contour, cavities, and pancreas divisum. All patients underwent endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: Dilated side branches were detected in three (20%) of 15 patients on MR cholangiopancreatograms obtained before secretin administration and in seven (47%) of 15 patients on images obtained after secretin administration. Ductal narrowing was detected in one (7%) of 15 patients on images obtained before secretin administration and in two (13%) of 15 patients on images obtained after secretin administration. Endoluminal filling defects in one (7%) of 15 patients were observed on MR cholangiopancreatograms obtained both before and after secretin administration. Irregular contour of the main pancreatic duct was present in four (27%) of 15 patients on MR cholangiopancreatograms obtained before secretin administration and in five (33%) of 15 patients on images obtained after secretin administration. Cavities and pancreas divisum were detected in one (7%) of 15 patients and in two (13%) of 15 patients, respectively, only on MR cholangiopancreatograms obtained after secretin administration. CONCLUSION: Secretin improves the sensitivity of MR cholangiopancreatography in diagnosing early-onset idiopathic chronic pancreatitis.     

Chronic pancreatitis: evaluation of pancreatic exocrine function with MR pancreatography after secretin stimulation

PURPOSE: To compare duodenal filling seen at magnetic resonance (MR) pancreatography after secretin stimulation and biochemical parameters determined with the intraductal secretin test (IDST) for evaluation of pancreatic exocrine function. MATERIALS AND METHODS: MR pancreatography after secretin stimulation and IDST were performed in 41 patients with chronic pancreatitis (group 1) and eight patients with other pancreatic disease (group 2). A control group (group 3, n = 28) underwent MR pancreatography after secretin stimulation only. MR pancreatograms were acquired before and every 30 seconds for 10 minutes after secretin injection. Duodenal filling was graded from least amount of filling (grade 1) to normal filling (grade 3) on the last MR pancreatogram. Pancreatic exocrine function was determined at IDST. Main pancreatic ductal diameter was compared between groups 1 and 3. RESULTS: All ductal diameters were significantly larger in group 1 (P <.001). The maximal diameter variation after secretin stimulation was significantly higher in the control group (P =.001). Pancreatic exocrine function parameters determined at IDST were significantly lower in patients with grade 1 duodenal filling than in those with grade 2 or 3 (P <.05). Maximal bicarbonate concentration alone was independently associated with all grades of duodenal filling (P =.007). The sensitivity and specificity of reduced duodenal filling for assessment of reduced pancreatic exocrine function were 72% and 87%, respectively. CONCLUSION: Duodenal filling grade determined at MR pancreatography after secretin stimulation allows specific estimation of pancreatic exocrine function.     

Pancreatic duct after pancreatoduodenectomy: morphologic and functional evaluation with secretin-stimulated MR pancreatography

OBJECTIVE: The purpose of this study was to evaluate the usefulness of secretin-enhanced MR pancreatography in evaluating morphologic changes and pancreatic function after pancreatoduodenectomy. SUBJECTS AND METHODS: Twenty patients who underwent pancreatoduodenectomy were evaluated with secretin MR pancreatography. Single-shot fast spin-echo T2-weighted dynamic MR pancreatograms were obtained before and every minute for 10 min after secretin injection. Image analysis included image quality for the visualization of the pancreatic duct and morphologic features of the pancreatic duct (side branches, ductal narrowing, irregular ductal contour, and patency of the anastomotic site). Pancreatic function was assessed using the Van de Kamer method and the fasting blood glucose and oral glucose tolerance tests. Jejunal filling was graded from the lowest amount of filling (grade 1) to normal filling (grade 3) on the last MR pancreatogram. RESULTS: The visualization of the main pancreatic duct was significantly improved with dynamic MR pancreatography (p < 0.05). The anastomotic site was visualized in 14 patients (70%) on MR pancreatography after secretin administration (p < 0.05). No statistically significant improvement in other morphologic data was seen after secretin administration. The sensitivity, specificity, positive predictive value, and negative predictive value of reduced jejunal filling (grade 1) for assessment of reduced pancreatic exocrine function were 92%, 71%, 85%, and 83%, respectively. The relation between reduced jejunal filling (grade 1) and diabetes was statistically significant (p < 0.05). CONCLUSION: The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of remnant pancreatic function after pancreatoduodenectomy.     

Severe chronic pancreatitis versus suspected pancreatic disease: dynamic MR cholangiopancreatography after secretin stimulation

PURPOSE: To assess whether secretin stimulation improves visualization of the pancreatic ducts at magnetic resonance (MR) cholangiopancreatography (MRCP) in patients with severe chronic pancreatitis or suspected pancreatic disease. MATERIALS AND METHODS: Thirty-one patients (group 1) with chronic pancreatitis and 84 patients (group 2) with clinical and/or laboratory findings suggestive of pancreatic disease who did not have ductal alterations at ultrasonography (US) and/or computed tomography (CT) underwent MRCP before and up to 10 minutes after secretin stimulation. Size of the main pancreatic duct (head, body, tail) and duodenal filling before and after secretin stimulation were measured quantitatively. Image quality, number of main pancreatic ductal segments visualized, visualization of side branches, ductal narrowing, endoluminal filling defects, and presence of pancreas divisum were analyzed qualitatively. RESULTS: In both groups, the size of the main pancreatic duct increased significantly 3 minutes after secretin stimulation. Reduced duodenal filling was detected in patients with severe chronic pancreatitis (P < .001). The number of segments of the main pancreatic duct visualized improved from 85 (91%) to 93 (100%) of 93 in group 1 and from 164 (65%) to 245 (97%) of 252 (P < .001) in group 2. Visualization of side branches improved from 22 (71%) to 31 (100%) of 31 in group 1 and from three (4%) to 53 (63%) of 84 (P < .001) in group 2. Pancreas divisum was visualized in one additional patient in group 1 and in six additional patients in group 2. CONCLUSION: The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of exocrine reserve.     

MR cholangiography: techniques and clinical applications

Magnetic resonance cholangiography (MRCP) is a new non-invasive imaging technique for the evaluation of bilio-pancreatic disorders. Different sequences, using both breathhold and non-breathhold techniques, have been employed in order to obtain MRCP images. The authors discuss the technical aspects, particularly focusing their attention on a non-breathhold, three-dimensional, fat-suppressed turbo-spin-echo sequence, optimized on a 0.5-T magnet with 15 mT/m gradients. Clinical applications of MRCP are evaluated, presenting data from both the literature and personal experience. The main indication for MRCP study is represented by the evaluation of common bile duct obstruction, with the aim of assessing the presence of the obstruction (accuracy 85–100 %) and, subsequently, its level (accuracy 91–100 %) and its cause. The utility of associating conventional MR images to MRCP in malignant strictures in order to characterize and stage the malignant lesions is also discussed. Finally, data are presented regarding the indications and utility of MR pancreatography in the evaluation of patients with chronic pancreatitis. Received 24 July 1997; Revision received 30 October 1997; Accepted 16 December 1997     

Intraductal tubular carcinoma of the pancreas: a case report with the imaging findings

We describe here a case of intraductal tubular carcinoma of the main pancreatic duct. Gadolinium-enhanced pancreas magnetic resonance (MR) imaging showed an enhancing mass that was confined in the dilated main pancreatic duct of the pancreatic body, along with dilatation of the upstream main pancreatic duct and chronic pancreatitis that was due to obstruction. MR cholangiopancreatography and an endoscopic retrograde pancreatogram showed a filling defect that was due to an intraductal mass of the pancreatic body, along with dilatation of the upstream main pancreatic duct and no dilatation of the downstream main pancreatic duct. The pathological findings demonstrated an intraductal nodular appearance without papillary projection or mucin hypersecretion.     

磁共振胰胆管造影临床应用的价值评价

目的：探讨磁共振胰胆管造影（MRCP）在胆胰疾病中的应用价值。方法：采用重T2加权MR水成像技术对73例患者行MRCP检查。图像经三维最大信号强度投影（3D-MIP）及三维表面遮蔽显示技术（3D-SSD）后处理。结果：73例患者,4例为正常胰胆管,69例胆胰疾病中,梗阻性黄疸者58例,其中恶性胆道梗阻43例,良性胆道梗阻15例,非梗阻性病变11例,在梗阻性黄疸病例中,MRCP定位准确率为100%,并清楚显示扩张胆管程度及断端形态,对于恶性胆阻性病变11例,在梗阻性黄疸病例中,MRCP定位准确率为100%,并清楚显示扩张胆管程度及断端形态。对于恶性胆道梗阻。结合常规MRI可明显提高定性准确率83.7%,同时可显示肿块大小、范围及周围脏器侵犯情况。良性梗阻MR-CP检查的定性准确率为92.9%。在非梗阻性病例中,MRCP可清楚描绘胆囊结石、胆系术后改变及含液丰富的病变（胰腺假性囊肿、总胆管囊肿、十二指肠憩室等）与胰胆管之间的毗邻关系。结论：MRCP可准确揭示胆管梗阻部位,明确病变性质,MRCP对于非梗阻性胆胰疾病则有助于了解病变与周围脏器的毗邻关系。但MRCP作为一种影像检查技术。不能脱离常规CT、MRI,而是对常规影像检查的一种有效补充。     

US-guided percutaneous pancreatography: an essential tool for imaging pancreatitis.

The pancreatic duct can be opacified when contrast material is injected through a fine needle percutaneously placed under ultrasound (US) guidance. Percutaneous pancreatography was performed in 63 patients with chronic pancreatitis diagnosed at US or computed tomography (CT). In 52 of these patients, endoscopic retrograde pancreatography (ERP) was unsuccessful or did not enable complete visualization of the duct. The percutaneous pancreatograms and other relevant images of these patients were retrospectively reviewed. Percutaneous pancreatography was successful in 54 patients (86%), in whom it clearly mapped the full ductal anatomy, depicted the relationship between cavities seen at US or CT and the duct, and allowed assessment of duct drainage after antegrade injection of contrast material. This information was not provided by other modalities. Percutaneous pancreatography is a valuable complement to CT, US, and ERP for imaging chronic pancreatitis.     

自身免疫性胰腺炎的MR诊断与鉴别诊断

目的分析自身免疫性胰腺炎的MRI表现,旨在提高对其诊断的准确率。方法对经临床证实的10例自身免疫性胰腺炎进行回顾性分析,10例均行MR平扫及增强扫描检查。结果胰腺弥漫性受累(8/10),胰头局限性肿块(1/10),胰体尾部受累(1/10);6例可见"假包膜"征。MRCP:9例胆总管胰腺段狭窄,8例见胰管局限性或弥漫性狭窄,1例主胰管未见显示;动态增强后病变区呈延迟性强化。结论 MRI表现有一定的特点,需要和其它胰腺病变进行鉴别诊断,从而做出正确的诊断。     

The interpretation of retrograde pancreatography in the elderly

Endoscopic retrograde pancreatography is regarded as the most specific technique in the diagnosis of chronic pancreatitis. In the elderly the relevance of endoscopic retrograde pancreatography changes in establishing the diagnosis is disputed. The pancreatograms of 101 patients aged seventy-five years or more, who had endoscopic retrograde pancreatography for suspected biliary or pancreatic pathology, were reviewed. Only four patients subsequently proved to have unequivocal chronic pancreatitis. There was no significant difference in the size or contour of the main pancreatic duct, or in side branch changes between those patients presenting with common bile duct stones, incidental biliary pathology and pain of probable pancreatic origin. Three definite diagnostic criteria for the diagnosis of chronic pancreatitis emerged--duct obstruction with a stricture, gross irregularity of the main pancreatic duct and the presence of large cavities.     

MRI of the biliary and pancreatic ducts

Magnetic resonance Cholangiopancreatography (MRCP) is a non-invasive imaging technique able to provide projectional images of the bile ducts. Different sequences, using both breath-hold and non-breath-hold acquisition techniques, have been employed in order to obtain MRCP images. The authors discuss technical aspects, considering both three-dimensional non-breath-hold techniques and two-dimensional breath-hold, multi-slice and thick slab sequences. Clinical applications of MRCP are evaluated, presenting data from both the literature and personal experience. The main indication for MRCP study is represented by the evaluation of common bile duct obstruction, with the aim of assessing the presence of the obstruction (accuracy 85–100 %) and, subsequently, its level (accuracy 91–100 %) and its cause. The utility of associating conventional MR images to MRCP in malignant strictures, in order to characterize and stage the malignant lesion, is also discussed. Finally, data are presented regarding the indications and the utility of MR-pancreatography in the evaluation of patients with pancreatic duct anomalies and chronic pancreatitis.     

Autoimmune pancreatitis: imaging features

PURPOSE: To retrospectively determine imaging findings in patients with autoimmune pancreatitis. MATERIALS AND METHODS: Twenty-nine patients (25 male and four female; mean age, 56 years; range, 15-82 years) with histopathologic diagnosis of autoimmune pancreatitis were examined. Data were reviewed by two radiologists in consensus. Imaging findings for review included those from helical computed tomography (CT), 25 patients; magnetic resonance (MR) imaging with MR cholangiopancreatography (MRCP), four patients; endoscopic ultrasonography (US), 21 patients; endoscopic retrograde cholangiopancreatography (ERCP), 19 patients; and percutaneous transhepatic cholangiography, one patient. Images were analyzed for appearances of pancreas, biliary and pancreatic ducts, and other findings, such as peripancreatic inflammation, encasement of vessels, mass effect, pancreatic calcification, peripancreatic nodes, and peripancreatic fluid collection. Follow-up images were available in nine patients. Serologic markers such as serum immunoglobulin G (IgG) and antinuclear antibody levels were available in 12 patients. RESULTS: CT showed diffuse (n = 14) and focal (n = 7) enlargement of pancreas. Seven patients had minimal peripancreatic stranding, with lack of vascular encasement, calcification, or peripancreatic fluid collection. Nine patients had enlarged peripancreatic lymph nodes. MR imaging showed focal (n = 2) and diffuse (n = 2) enlargement with rimlike enhancement in one. MRCP revealed pancreatic duct strictures in two and sclerosing cholangitis-like appearance in one. Endoscopic US showed diffuse enlargement of pancreas with altered echotexture in 13 patients and focal mass in the head in six. ERCP showed stricture of distal common bile duct in 12 patients, irregular narrowing of intrahepatic ducts in six, diffuse irregular narrowing of pancreatic duct in nine, and focal stricture of proximal pancreatic duct in six. Serologic markers showed increased IgG and antinuclear antibody levels in seven of 12 patients. At follow-up, CT abnormalities and common bile duct strictures resolved after steroid therapy in three patients. CONCLUSION: Features that suggest autoimmune pancreatitis include focal or diffuse pancreatic enlargement, with minimal peripancreatic inflammation and absence of vascular encasement or calcification at CT and endoscopic US, and diffuse irregular narrowing of main pancreatic duct, with associated multiple biliary strictures at ERCP.     

Filling defects in the pancreatic duct on endoscopic retrograde pancreatography.

Filling defects in the pancreatic duct are a frequent finding during endoscopic retrograde pancreatography (ERP) and have a variety of causes. Some filling defects may be artifactual or related to technical factors and, once their origin is recognized, can be disregarded. Others may be due to acute changes of pancreatitis and should prompt more careful injection of contrast material into the duct. Intraluminal masses may represent calculi or a neoplasm, either of which may require surgery or endoscopic intervention. The exact nature of these filling defects may not be apparent on radiographs, and other studies may be needed. This article reviews our approach to the evaluation of filling defects in the pancreatic duct.     

MR characteristics of acute cholangitis

Purpose: To describe the MR appearance of acute cholangitis and discuss the role of MR imaging as a diagnostic method in this disease.Material and Methods: Of 60 patients with clinical acute cholangitis, 12 were examined with MR before endoscopic retrograde pancreatography (ERCP). A retrospective review was performed of MR and ERCP findings. The MR findings registered were presence of biliary duct dilatation, intraluminal filling defects due to stones or sludge, bands of mucosal oedema of the biliary ducts, intra- and retroperitoneal oedema/fluid, and definition of the cause of obstruction, e.g. stones, stenosis or tumour was made.Results: Acute cholangitis was related to obstruction from choledocholithiasis (n=8), pancreatic cancer (n=1), benign biliary duct stricture (n=1), papillary stenosis (n=1) and without evidence of an obstructing cause (n=1). One patient had an acute obstructive suppurative (toxic) cholangitis.Conclusion: MR imaging has a role in the non-invasive radiographic arsenal of techniques to confirm or exclude the diagnosis of acute cholangitis, especially in older patients where the clinical symptoms may be vague.     

磁共振胰胆管成像的临床应用价值

目的：研究磁共振胰胆管成像（ＭＲＣＰ）的临床应用价值。材料与方法：前瞻与回顾性分析了８例正常志愿者、６例慢性胰腺炎和３３例梗阻性黄疸的ＭＲＣＰ检查。结果：ＭＲＣＰ清楚显示１４例正常左、右肝管，肝总管，胆总管和胆囊；冠状位、横轴位分别清楚显示５３９％和８６７％的正常胰管；ＭＲＣＰ结合ＭＲＩ常规平扫前瞻性诊断梗阻性黄疸的准确率为９３３％。结论：ＭＲＣＰ具有重要的临床应用价值     

MR imaging of pancreatic diseases

This article presents current MR imaging techniques for the pancreas, and review a spectrum of MR imaging features of various pancreatic diseases. These include: 1) congenital anomalies such as anomalous union of pancreatobiliary ducts, divisum, and annular pancreas, 2) inflammatory diseases, including acute or chronic pancreatitis with complications, groove pancreatitis, and autoimmune pancreatitis, tumor-forming pancreatitis, 3) pancreatic neoplasms, including adenocarcinoma, islet cell tumors, and cystic neoplasms (microcystic adenoma, mucinous cystic neoplasms, and intraductal mucin-producing pancreatic tumor). Particular attention is paid to technical advances in MR imaging of the pancreas such as fat-suppression, MR pancreatography (single- or multi-slice HASTE), and thin-section 3D multiphasic contrast-enhanced dynamic sequences. Imaging characteristics that may lead to a specific diagnosis or narrow the differential diagnosis are also discussed.     

Prospective evaluation of pancreatic tumors: accuracy of MR imaging with MR cholangiopancreatography and MR angiography

PURPOSE: To prospectively assess accuracy of magnetic resonance (MR) imaging, MR cholangiopancreatography (MRCP), and MR angiography in patients suspected of having pancreatic tumors. MATERIALS AND METHODS: Sixty-six patients suspected of having pancreatic tumors underwent MR imaging (unenhanced and contrast material-enhanced MR, MRCP, and contrast-enhanced MR angiography). Two blinded readers prospectively analyzed the images by consensus, and results were correlated with surgery, biopsy, or follow-up findings. Results were tabulated in two-by-two tables. RESULTS: MR assessment of pancreatic lesion status (differentiation of benign vs malignant) resulted in 60 correct diagnoses (accuracy, 91%), and six (10%) false diagnoses. Among histologically proved malignant tumors, MR imaging yielded correct diagnoses in 42 of 44 patients (sensitivity, 95%; 95% CI: 85%, 99%), whereas 18 of 22 patients with benign findings were classified correctly. At MR imaging, findings in four patients with chronic pancreatitis were wrongly categorized as malignant tumors (specificity, 82%; 95% CI: 60%, 95%), and in one patient, a distal common bile duct carcinoma was not detected. In no patient with pancreatic adenocarcinoma was this tumor misdiagnosed as benign. In patients with malignant tumors who underwent resection, local-regional tumor growth and vascular infiltration were accurately classified in 89% and 94%, respectively. MR imaging depicted histologically proved synchronous hepatic metastases in 82%. The positive and negative predictive values for cancer nonresectability were 90% and 83%, respectively, and the accuracy, sensitivity, and specificity were 85%, 69%, and 95%, respectively. CONCLUSION: Unenhanced and contrast-enhanced MR imaging with MRCP and MR angiography offers potential as a noninvasive tool for assessment of patients suspected of having pancreatic tumors.     

3.0T MRI对胰腺假性囊肿的研究

目的 研究急性胰腺炎与慢性胰腺炎后胰腺假性囊肿(PPC) 的MRI 特征.资料与方法 回顾分析2007 年-2011 年40 例连续的胰腺假性囊肿病人的临床与影像学资料,2 名有经验的放射科医师比较分析急性胰腺炎与慢性胰腺炎后假性囊肿在不同MR 脉冲序列的影像学表现.观察项目包括病灶部位、大小、边界、形态、壁结节、囊内分隔、囊液信号、囊内碎屑及假性囊肿与主胰管关系.结果 急性胰腺炎后假性囊肿囊内碎屑发生率高于慢性胰腺炎后假性囊肿(χ2=12.931,P=0.000),慢性胰腺炎后假性囊肿与主胰管交通显示率高于急性胰腺炎后假性囊肿(χ2=8.913,P=0.003),且组间差异均有统计学意义.T1WI、T2WI 及磁共振胆胰管成像(MRCP)对PPC 与主胰管交通的显示率分别为12.24%、34.69%、40.82%,其差异具有统计学意义(χ2 =10.716,P=0.005).结论 综合应用各种MR 脉冲序列能够对PPC 做出准确评价.     

US-guided percutaneous pancreatography: experience in 75 patients

Seventy-five patients underwent ultrasound (US)-guided percutaneous pancreatography during a 3 1/2-year period. Pancreatography was successful in 67 patients, and there were no significant complications. The technique, which is easy to perform, was primarily employed to assist localization of pancreatic masses at fine-needle aspiration biopsy. It was also used to demonstrate pancreatic duct morphology when endoscopic retrograde pancreatography had failed or proved non-diagnostic. This enabled mapping of the duct system prior to pancreatic surgery. In cases of diagnostic difficulty, assessment of duct appearance with US-guided pancreatography was more accurate in differentiating carcinoma from chronic pancreatitis than was assessment with endoscopic retrograde pancreatography.