Non-invasive quantification of pancreatic exocrine function using secretin-stimulated MRCP

Our objective was to quantify water volume using magnetic resonance cholangiopancreatography (MRCP) sequences and apply this to secretin-stimulated studies with the aim of quantifying pancreatic exocrine function. A commercially available single-shot MRCP sequence was used in conjunction with a body phased-array coil and a 1.5-T MR system. Signal intensity was measured in samples of water, pancreatic, duodenal juice, and secretin-stimulated pancreatic juice. A water phantom was made and MR calculated volumes compared with known water volumes within the phantom. Changes in small intestinal volume in response to secretin were measured in a group of 11 patients with no evidence of pancreatic disease. Changes in water volume were plotted over time. The pancreatic duct diameter before and after secretin was noted and filling defects were sought. All patients also underwent an axial breath-hold T1-weighted gradient-echo sequence and the pancreatic parenchyma was evaluated for size and signal intensity. There was no difference in the signal intensity of the different juice samples. There was excellent correlation between known and calculated MRCP volumes (χ²=0.99). All patients demonstrated normal duct morphology on MRCP and normal pancreatic parenchyma on T1-weighted imaging. The mean flow rate in the patient population was 8.1±2.5 ml/s over a median of 7 min (range 5–9 min). The MRCP sequence can be used to measure water volume. Sequential MRCP measurements following secretin permitted calculation of volume change and flow rate. This should prove useful as an indicator of pancreatic exocrine function. Electronic Publication     

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.     

Diffuse pancreatic ductal adenocarcinoma: characteristic imaging features

PURPOSE: To evaluate imaging findings of diffuse pancreatic ductal adenocarcinoma. MATERIALS AND METHODS: We included 14 patients (4 men and 10 women; mean age, 64.5 years) with diffuse pancreatic ductal adenocarcinoma on the basis of retrospective radiological review. Two radiologists retrospectively reviewed 14 CT scans in consensus with respect to the following: tumor site, peripheral capsule-like structure, dilatation of intratumoral pancreatic duct, parenchymal atrophy, and ancillary findings. Eight magnetic resonance (MR) examinations with MR cholangiopancreatography (MRCP) and seven endoscopic retrograde cholangiopancreatography (ERCP) were also reviewed, focusing on peripheral capsule-like structure and dilatation of intratumoral pancreatic duct. RESULTS: CT revealed tumor localization to the body and tail in 11 (79%) patients and peripheral capsule-like structure in 13 (93%). The intratumoral pancreatic duct was not visible in 13 (93%). Pancreatic parenchymal atrophy was not present in all 14 patients. Tumor invasion of vessels was observed in all 14 patients and of neighbor organs in 8 (57%). On contrast-enhanced T1-weighted MR images, peripheral capsule-like structure showed higher signal intensity in five patients (71%). In all 11 patients with MRCP and/or ERCP, the intratumoral pancreatic duct was not dilated. CONCLUSION: Diffuse pancreatic ductal adenocarcinoma has characteristic imaging findings, including peripheral capsule-like structure, local invasiveness, and absence of both dilatation of intratumoral pancreatic duct and parenchymal atrophy.     

MRI assessment of chronic pancreatitis

Magnetic resonance imaging (MRI) plays an important role in the assessment of chronic pancreatitis. By standard MRI techniques, decreased parenchymal signal on T1-weighted fat-suppressed images and delayed gradual enhancement on serial contrast enhanced images represent fibrotic changes caused by chronic inflammation. Magnetic resonance cholangiopancreaticography (MRCP) can reveal ductal changes, including side branch ectasias, that are related to tissue fibrosis and destruction. The exocrine function of the gland and an increased number of side branch ectasias can be evaluated with secretin-stimulated MRCP. Diffusion weighted imaging is an emerging technology that can complement standard MRI to assess the parenchymal changes associated with chronic pancreatitis. The same technique can also quantify the parenchymal response to secretin stimulation. This article reviews standard imaging techniques and new advancements in MRI technology as they relate to the assessment of chronic pancreatitis.     

Pancreatic duct: morphologic evaluation with MR cholangiopancreatography after secretin stimulation

PURPOSE: To evaluate the pancreatic duct after administration of secretin. MATERIALS AND METHODS: Single-shot turbo spin-echo T2-weighted dynamic magnetic resonance cholangiopancreatography (MRCP) was performed in 85 patients who did not have pancreatic diseases (group 1) and in 50 patients who had focal severe stenosis of the main pancreatic duct (group 2). The visualization and diameter of the pancreatic duct before and after secretin administration were assessed. RESULTS: In group 1, after secretin administration, the best visualization of the main pancreatic duct in the head, body, accessory pancreatic duct, and branch ducts was achieved in 4.7 minutes +/- 1.6 (SD), 4.8 minutes +/- 1.6, 4.6 minutes +/- 1.6, and 4.7 minutes plus minus 1.3, respectively. Improvement in the delineation of the main pancreatic duct in the head (78 [92%] patients), body (80 [94%] patients), accessory pancreatic duct (35 [41%] patients), and branch ducts (14 [16%] patients) was achieved. Overlap of fluid in the organ and the pancreatic duct was observed in 20 (24%) of 85 patients. Overlap was especially observed after 5 minutes of secretin injection. In group 2, the best visualization of the distal main pancreatic duct was achieved 4.9 minutes +/- 1.4 after secretin administration. Improvement in the delineation of the distal main pancreatic duct was achieved in 17 (85%) of 20 patients. CONCLUSION: MRCP is best performed during the first 5 minutes after secretin administration.     

Blunt pancreatic trauma: A persistent diagnostic conundrum?

Blunt pancreatic trauma is an uncommon injury but has high morbidity and mortality. In modern era of trauma care, pancreatic trauma remains a persistent challenge to radiologists and surgeons alike. Early detection of pancreatic trauma is essential to prevent subsequent complications. However early pancreatic injury is often subtle on computed tomography (CT) and can be missed unless specifically looked for. Signs of pancreatic injury on CT include laceration, transection, bulky pancreas, heterogeneous enhancement, peripancreatic fluid and signs of pancreatitis. Pan-creatic ductal injury is a vital decision-making parameter as ductal injury is an indication for laparotomy. While lacerations involving more than half of pancreatic parenchyma are suggestive of ductal injury on CT, ductal injuries can be directly assessed on magnetic resonance imaging (MRI) or encoscopic retrograde cholangio-pancreatography. Pancreatic trauma also shows temporal evolution with increase in extent of injury with time. Hence early CT scans may underestimate the extent of injures and sequential imaging with CT or MRI is important in pancreatic trauma. Sequential imaging is also needed for successful non-operative management of pancreatic injury. Accurate early detection on initial CT and adopting a multimodality and sequential imaging strategy can improve outcome in pancreatic trauma.     

胃肠道阴性对比剂在磁共振胰胆管成像中的应用

目的：评价马根维显（Gd—DTPA）溶液作为胃肠道阴性对比剂对改善磁共振胰胆管成像（MRCP）质量的价值。方法：对30例疑有胰、胆管系统疾病的患者口服对比剂前后分别行常规腹部MR和MRCP检查,采用相同的扫描参数及定位。结果：所有病例口服对比剂后MRCP扫描,胃及十二指肠内液体高信号均较前有明显下降,图像质量明显提高。口服稀释的Gd—DTPA溶液前后,MRCP检查胆总管、胰管及胆囊结构的显示效果具有显著性意义（P〈0．05）。结论：口服稀释的Gd—DTPA溶液是一种安全有效降低胃肠道液体高信号强度、改善MRCP图像质量的方法。     

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.     

Imaging of blunt pancreatic trauma

Blunt pancreatic trauma is an exceedingly rare but life-threatening injury with significant mortality. Computed tomography (CT) is commonly employed as the initial imaging modality in blunt trauma patients and affords a timely diagnosis of pancreatic trauma. The CT findings of pancreatic trauma can be broadly categorized as direct signs, such as a pancreatic laceration, which tend to be specific but lack sensitivity and indirect signs, such as peripancreatic fluid, which tend to be sensitive but lack specificity. In patients with equivocal CT findings or ongoing clinical suspicion of pancreatic trauma, magnetic resonance cholangiopancreatography (MRCP) may be employed for further evaluation. The integrity of the main pancreatic duct is of crucial importance, and though injury of the duct may be strongly suggested upon initial CT, MRCP provides clear delineation of the duct and any potential injuries. This article aims to review and illustrate the CT and magnetic resonance imaging findings of blunt pancreatic trauma and delineate the integration of these modalities into the appropriate imaging triage of severely injured blunt trauma patients.     

Pancreas divisum and santorinicele: assessment by dynamic magnetic resonance cholangiopancreatography during secretin stimulation

PURPOSE: To evaluate the usefulness of MRCP, before and after secretin administration, in diagnosing Santoriniceles in patients with pancreas divisum. MATERIAL AND METHODS: One hundred and eight patients with suspected pancreatic disease, underwent dynamic magnetic resonance cholangiopancreatography (MRCP) before and after secretin administration (S-MRCP). S-MRCP images were evaluated for presence/absence of pancreas divisum, Santorinicele; size of the main pancreatic duct and of the Santorinicele. The onset of duodenal filling was calculated on dynamic S-MRCP images. S-MRCP findings were compared to endoscopic retrograde cholangiopancreatography (ERCP) ones (39/108). RESULTS: Pancreas divisum (PD) was detected in 6/108 patients (6%) at MRCP, and in 16/108 patients (14%) at S-MRCP. ERCP confirmed the diagnosis in 12/16 patients, with 1 false positive. 3 patients did not undergo ERCP. Santorinicele was detected in 4/108 (3%) patients at MRCP and in additional 4/108 (3%) patients at S-RMCP, only in patients with PD. Santoriniceles were confirmed in 7/8 patients at ERCP; in 1/8 patient CPRE was unsuccessful. The duct of Santorini was significantly larger (p< 0.05), in the pancreatic head, in patients with PD and Santorinicele (3.6 mm) compared to those with PD only (2.2 mm). A significant reduction in size of the pancreatic duct (26%) and of the Santorinicele (63%) was observed after sphincterotomy. The onset of duodenal filling was significantly delayed in patients with Santorinicele (2.1 vs 1.3 minutes)(p<0.05). CONCLUSIONS: S-MRCP helps to identify patients with pancreas divisum and Santorinicele, a known cause of impeded pancreatic outflow which benefits from endoscopic treatment.     

Autoimmune pancreatitis: imaging findings on contrast-enhanced MR, MRCP and dynamic secretin-enhanced MRCP

Purpose

This study retrospectively determined magnetic resonance (MR), MR cholangiopancreatography (MRCP) and secretin-MRCP findings in patients with autoimmune pancreatitis (AIP).

Materials and methods

The MR examinations of 28 patients with histopathologically proven AIP were reviewed. In 14 cases, secretin-enhanced MRCP was performed. The observers evaluated pancreatic parenchymal enlargement, signal intensity abnormalities, enhancement, vascular involvement, bile-duct diameter and main pancreatic duct (MPD) narrowing (diffuse/focal/segmental). After secretin administration, the presence of the “duct-penetrating” sign was evaluated.

Results

MR imaging showed diffuse pancreatic enlargement in 8/28(29%) cases, focal pancreatic enlargement in 16/28 (57%) cases and no enlargement in 4/28 (14%) cases. The alteration of pancreatic signal intensity was diffuse in 8/28 (29%) cases (eight diffuse AIP) and focal in 20/28 (71%) cases (20 focal AIP). Delayed pancreatic enhancement was present in all AIP, with peripheral rim of enhancement in 8/28 (29%) AIP (1/8 diffuse, 7/20 focal); vascular encasement was present in 7/28 (25%) AIP (1/8 diffuse, 6/20 focal); distal common bile duct narrowing was present in 12/28(43%) AIP (5/8 diffuse, 7/20 focal). MRCP showed MPD narrowing in 17/28 (61%) AIP (4/8 diffuse, 15/20 focal), MPD dilation in 8/28(29%) AIP (3/8 diffuse, 5/20 focal) and normal MPD in1/8 diffuse AIP. Secretin-MRCP showed the duct-penetrating sign in 6/14(43%) AIP (one diffuse AIP with MPD segmental narrowing, five focal AIP with MPD focal narrowing), demonstrating integrity of the MPD.

Conclusions

Delayed enhancement and MPD stenosis are suggestive for AIP on MR and MRCP imaging. Secretin-enhanced MRCP is a problem-solving tool in the differential diagnosis between focal AIP and ductal adenocarcinoma.     

胰腺外分泌功能的MRI研究进展

胰腺外分泌功能检查对胰腺生理功能研究及胰腺外分泌功能不全相关性疾病的诊断及疗效评估有十分重要的意义。近年来,多种MRI技术用于检测胰腺外分泌功能,如胰泌素刺激增强MR胆胰管水成像（s-MRCP）可进行功能诊断及分级,基于扩散加权的磁共振成像（DW-MRI）能够对主胰管内胰液的流速进行半定量检测,基于空间选择反转恢复脉冲的电影胆胰管水成像（CINE-MRCP）可直接观察胰管内胰液流动。综述常用胰腺外分泌功能MRI检查技术及应用进展。     

Three-dimensional fast-recovery fast spin-echo MRCP: comparison with two-dimensional single-shot fast spin-echo techniques

PURPOSE: To retrospectively evaluate the technical quality of and the visibility of the biliary tree and pancreatic duct on magnetic resonance (MR) cholangiopancreatographic (MRCP) images obtained with a single-breath-hold three-dimensional (3D) fast-recovery fast spin-echo (FRFSE) sequence in comparison with conventional two-dimensional (2D) single-shot fast spin-echo (SSFSE) thin-section and thick-slab sequences. MATERIALS AND METHODS: Institutional review board approval was obtained; informed consent was not required for this HIPAA-compliant study. MRCP was performed at 1.5 T in 53 consecutive patients (25 men and 28 women, aged 23-84 years). A single-breath-hold volume acquisition was performed by using the 3D FRFSE sequence and the conventional 2D SSFSE sequences. Two radiologists graded studies obtained with each sequence in a blinded fashion, and the paired Student t test was used to assess differences in technical quality, visibility of eight individual ductal segments of the biliary tree and pancreatic duct, and number of ductal segments visualized per patient. RESULTS: Studies obtained with 3D FRFSE were of significantly higher technical quality than those obtained with thin-section 2D SSFSE (P < .02 for both readers). The 3D FRFSE maximum intensity projection reconstruction and 2D SSFSE thick-slab sequence proved statistically equivalent with regard to the overall visibility of the biliary tree and pancreatic duct and the number of ductal segments visualized per patient. In comparison with 2D SSFSE thin-section imaging, however, 3D FRFSE imaging produced an improved overall duct segment visibility grade of 0.45 on a three-point visibility scale (P < .001), with a corresponding average per-patient improvement of 1.9 out of eight possible fully visualized duct segments (P < .001). CONCLUSION: The 3D FRFSE sequence shows promise for improved visibility of the pancreatic duct and biliary tree, compared with the conventional 2D SSFSE thin-section and thick-slab approach, while permitting the entire MRCP examination to be performed in a single breath hold.     

静脉注射联合口服钆喷酸葡胺磁共振胆胰管成像在低场强MR的应用

目的分析口服稀释静脉用钆喷酸葡胺溶液作为低场强磁共振胃肠道阴性对比剂及联合静脉注射钆喷酸葡胺磁共振胆胰管成像(MRCP)在低场MR中用于显示胆胰管及疾病的能力。方法 30例临床可疑有胆胰管病变的患者,均有不同程度胆系梗阻、腹痛、不同程度皮肤或巩膜黄染等,部分有腹部肿块,均行MR平扫、Gd-DTPA(钆喷酸葡胺)强化检查,部分同时行超声及CT检查。结果 30例受检者均能清楚显示胆胰管树,并能清晰显示病变位置,其中18例发现肝内胆管占位,10例发现肝内胆管、肝外胆管及(或)胆囊结石,2例胰头占位。结论口服钆喷酸葡胺溶液可抑制胃及十二指肠内潴留液的高信号以及胆胰管树背景的小血管信号,改善MRCP图像的质量,结合肝胆MR平扫、强化应用具有较高的肝内、外胆管显示率及肝内、外胆管病变的显示能力,能为胆胰管病变的诊断及鉴别诊断提供更多帮助。     

MRI and S‐MRCP findings in patients with suspected chronic pancreatitis: Correlation with endoscopic pancreatic function testing (ePFT)

Purpose:

To review magnetic resonance imaging (MRI) and secretin stimulated magnetic resonance cholangiopancreatography (S‐MRCP) findings of patients with suspected chronic pancreatitis and compare them with endoscopic pancreatic function testing (ePFT).

Materials and Methods:

MRI and S‐MRCP findings of 36 patients with clinically suspected chronic pancreatitis were reviewed. Baseline ductal changes, duodenal filling grades, and pancreatic duct caliber change (PDC) on S‐MRCP, mean values of pancreatic anteroposterior (AP) diameter, signal intensity ratio (SIR) between pancreas and the spleen on T1‐weighted fat saturated images, and arterial to venous (A/V) enhancement ratios were compared between groups of normal and abnormal pancreatic exocrine function determined by ePFT.

Results:

All patients (n = 24) with normal ePFT (HCO₃ >80 mEq/L) had grade 3 normal duodenal filling. Patients with abnormal ePFT (HCO₃ <80 mEq/L) (n = 12) had grade 1 (n = 1) and grade 2 (n = 11) diminished duodenal filling (P < 0.0001). PDC was 1.51 in the normal ePFT group versus 1.27 in the abnormal ePFT group (P = 0.01). No significant differences were found in terms of mean pancreatic AP diameter (21.8 vs. 19.8 cm), SIR (1.59 vs. 1.44), and A/V (1.08 vs. 1.01) between groups of normal/abnormal pancreatic exocrine function.

Conclusion:

Despite discrepancies between pancreatic exocrine function and the findings on standard MRI/MRCP, the S‐MRCP findings are comparable to ePFT in the evaluation of chronic pancreatitis. J. Magn. Reson. Imaging 2010;31:601–606. © 2010 Wiley‐Liss, Inc.     

MRI of oriental cholangiohepatitis

Oriental cholangiohepatitis (OCH) also called recurrent pyogenic cholangitis is characterized by intrahepatic duct calculi, strictures, and recurrent infections. In turn cholangitis can result in multiple hepatic abscesses, further biliary strictures, and in severe cases, progressive hepatic parenchymal destruction, cirrhosis, and portal hypertension. Magnetic resonance cholangiopancreatography (MRCP) and conventional T1-weighted (T1W) and T2-weighted (T2W) magnetic resonance imaging (MRI) findings have been described in patients with OCH. MRCP findings include duct dilation, strictures, and calculi. MRCP can help to localize the diseased ducts and determine the severity of involvement. T1 and T2W sequences reveal the parenchymal changes of atrophy, abscess formation, and portal hypertension in addition to calculi. Post-treatment changes are also well depicted using MRI. Comprehensive, non-invasive assessment is achieved by using conventional MRI and MRCP in OCH providing a roadmap for endoscopic or surgical management.     

Quantitative secretin MRCP (MRCPQ): results in 215 patients with known or suspected pancreatic pathology

Secretin magnetic resonance cholangiopancreatography quantification (MRCPQ) of pancreatic exocrine function correlates well with steatorrhoea and conventional, non-invasive function tests. We report MRCPQ results in a variety of pancreatic conditions. A total of 215 patients [107 male, mean age 46 years (14-78)] were studied. A multi-slice MRCP sequence was performed before and at 2-min intervals after 0.1 ml/kg IV secretin. Change in small intestinal water volume was plotted against time and the flow rate derived from the gradient. Patients were classified using clinical history, MRCP, MR imaging, computed tomography (CT) [150/215 (70%)] and endoscopic retrograde cholangiopancreatography (ERCP) [56/215 (26%)] findings but not MRCPQ results. Mean, standard deviation and 95% confidence intervals were calculated. The one way ANOVA and Student's t-test were used for statistical analysis. Seventy-six patients had chronic pancreatitis, 26 were post-surgical, 34 post-acute pancreatitis, six atrophic pancreatopathy, eight with obstruction, 15 divisum, ten sphincter of Oddi dysfunction, 26 normal and 14 miscellaneous. Significant differences were observed between normals (mean+/-SD; 7.4 +/- 2.9 ml/min) and severe chronic pancreatitis (5.3 +/- 2.4) (P = 0.018), pancreatic atrophy (3.8 +/- 3.1) (P = 0.013) or duct obstruction (5.3 +/- 2.4) (P = 0.047)) and between moderate (7.0 +/- 3.0) (P = 0.03) and severe chronic pancreatitis. MRCPQ can be used to quantify function across the spectrum of pancreatic disease and showed significant differences between several different pathologies.     

MR imaging techniques for pancreas

Pancreatic magnetic resonance (MR) imaging has become a useful tool in evaluating pancreatic disorders. Technical innovations in MR imaging have evolved over the last decade, with most sequences being performed in one or a few breath-holds. Three-dimensional sequences with thin, contiguous slices allow for improved spatial resolution on the postgadolinium images and MR cholangiopancreatography (MRCP). The diagnostic potential of MRCP is equivalent to endoscopic retrograde pancreatography, particularly when intravenous secretin is used to enhance the pancreatic duct assessment. This article highlights the advantages and disadvantages of state-of-the-art and emerging pulse sequences and their application to imaging pancreatic diseases.     

Choledochocele with pancreas divisum:A rare cooccurrence diagnosed on magnetic resonance cholangiopancreatography

We report a case of a 42-year-old male with symptomatic choledochocele and incidental pancreas divisum diagnosed with magnetic resonance cholangiopancreatography (MRCP). Small choledochocele is rare congenital malformation associated with non-specific symptoms and a delay in diagnosis. The coexistence of choledochocele and pancreas divisum is extremely rare with only two case reports published in literature. In both cases MRCP failed to diagnose any biliary or pancreatic abnormality. This case suggests that the patients with recurrent abdominal pain and pancreas divisum should not be presumed to be suffering from pancreatitis. Careful evaluated for additional anomalies in the biliary tree should be sought for refractory symptoms. MRCP is a useful one-stop-shop for diagnosing pancreatic and biliary ductal anomalies.     

Pitfalls in MR cholangiopancreatographic interpretation.

Magnetic resonance (MR) cholangiopancreatography (MRCP) is widely used in the evaluation of pancreatobiliary disorders. However, numerous related pitfalls may simulate or mask pancreatobiliary disease. Maximum-intensity-projection (MIP) reconstructed images completely obscure small filling defects and may demonstrate respiratory motion artifacts. T2 weighting may vary with different MR imaging sequences and influence MRCP findings. Incomplete imaging may create confusion regarding ductal anatomy or disease. Furthermore, MRCP yields only static images and thus may fail to depict various anomalies. Limited spatial resolution makes differentiation between benign and malignant strictures with MRCP alone extremely difficult. Susceptibility artifacts may be caused by metallic foreign bodies or gastric-duodenal gas. Fluid accumulation may produce a pseudolesion or pseudostricture, although changing the imaging angle or section thickness may be helpful. Pneumobilia may be misinterpreted as bile duct stones, and true stones may be overlooked. Pulsatile vascular compression can cause pseudo-obstruction of the bile duct. Use of both source and MIP reconstructed images obtained from different angles can help avoid cystic duct-related pitfalls. Repeat MRCP or conventional MR imaging can help avoid pitfalls related to the periampullary region. Segmental collapse of the normal main pancreatic duct may be misinterpreted as stenosis, but administration of secretin is helpful. An awareness of these pitfalls and possible solutions is crucial for avoiding misinterpretation of MRCP images.