Secretin-enhanced Magnetic Resonance Cholangiopancreatography Research Articles

Endoscopic Ultrasound in Pancreatic Duct Anomalies.

Embryological development of the pancreas is a complex phenomenon and, therefore, it can have multiple developmental aberrations. Fortunately, the majority of these pancreatic ductal anomalies are asymptomatic with no clinical relevance and are incidentally detected during diagnostic cross-sectional imaging or endoscopic retrograde cholangiopancreatography (ERCP) or autopsy. Occasionally, pancreatic duct anomalies can result in symptoms like abdominal pain or recurrent pancreatitis. Also, an accurate pre-operative diagnosis of ductal anomalies can prevent inadvertent duct injury during surgery. Conventionally, ERCP had been used for an accurate diagnosis of pancreatic duct anomalies. However, because it is invasive and associated with a risk of pancreatitis, it has been replaced with magnetic resonance cholangiopancreatography (MRCP). MRCP has demonstrated high sensitivity and specificity for the diagnosis of ductal anomalies, which can be further improved with the use of secretin-enhanced MRCP. Endoscopic ultrasound (EUS) is a new diagnostic and interventional tool in the armamentarium of endoscopists and has demonstrated promising results in the detection of pancreatic duct variations and anomalies. Along with the visualization of the course and configuration of the pancreatic duct, EUS can also visualize changes in the pancreatic parenchyma, thereby helping with an early diagnosis of any co-existent pancreatic disease. Absence of the stack sign and crossed duct sign are important EUS features to diagnose pancreas divisum. EUS can also help with the diagnosis of other congenital ductal anomalies like annular pancreas, ansa pancreatica, and anomalous pancreaticobiliary union, although the published experience is limited.

Replacing secretin-enhanced MRCP with MRI radiomics model based on a fully automated pancreas segmentation for assessing pancreatic exocrine function in chronic pancreatitis.

To develop and validate a radiomics nomogram based on a fully automated pancreas segmentation to assess pancreatic exocrine function. Furthermore, we aimed to compare the performance of the radiomics nomogram with the pancreatic flow output rate (PFR) and conclude on the replacement of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) by the radiomics nomogram for pancreatic exocrine function assessment. All participants underwent S-MRCP between April 2011 and December 2014 in this retrospective study. PFR was quantified using S-MRCP. Participants were divided into normal and pancreatic exocrine insufficiency (PEI) groups using the cut-off of 200µg/L of fecal elastase-1. Two prediction models were developed including the clinical and non-enhanced T1-weighted imaging radiomics model. A multivariate logistic regression analysis was conducted to develop the prediction models. The models' performances were determined based on their discrimination, calibration, and clinical utility. A total of 159 participants (mean age [Formula: see text] standard deviation, 45years [Formula: see text] 14;119 men) included 85 normal and 74 PEI. All the participants were divided into a training set comprising 119 consecutive patients and an independent validation set comprising 40 consecutive patients. The radiomics score was an independent risk factor for PEI (odds ratio = 11.69; p < 0.001). In the validation set, the radiomics nomogram exhibited the highest performance (AUC, 0.92) in PEI prediction, whereas the clinical nomogram and PFR had AUCs of 0.79 and 0.78, respectively. The radiomics nomogram accurately predicted pancreatic exocrine function and outperformed pancreatic flow output rate on S-MRCP in patients with chronic pancreatitis. • The clinical nomogram exhibited moderate performance in diagnosing pancreatic exocrine insufficiency. • The radiomics score was an independent risk factor for pancreatic exocrine insufficiency, and every point rise in the rad-score was associated with an 11.69-fold increase in pancreatic exocrine insufficiency risk. • The radiomics nomogram accurately predicted pancreatic exocrine function and outperformed the clinical model and pancreatic flow output rate quantified by secretin-enhanced magnetic resonance cholangiopancreatography on MRI in patients with chronic pancreatitis.

Endoscopic management of pancreatic fluid collections with disconnected pancreatic duct syndrome.

Disconnected pancreatic duct syndrome (DPDS) is an important and common complication of acute necrotizing pancreatitis. Endoscopic approach has been established as the first-line treatment for pancreatic fluid collections (PFCs) with less invasion and satisfactory outcome. However, the presence of DPDS significantly complicates the management of PFC; besides, there is no standardized treatment for DPDS. The diagnosis of DPDS presents the first step of management, which can be preliminarily established by imaging methods including contrast-enhanced computed tomography, ERCP, magnetic resonance cholangiopancreatography (MRCP), and EUS. Historically, ERCP is considered as the gold standard for the diagnosis of DPDS, and secretin-enhanced MRCP is recommended as an appropriate diagnostic method in existing guidelines. With the development of endoscopic techniques and accessories, the endoscopic approach, mainly including transpapillary and transmural drainage, has been developed as the preferred treatment over percutaneous drainage and surgery for the management of PFC with DPDS. Many studies concerning various endoscopic treatment strategies have been published, especially in the recent 5 years. Nonetheless, existing current literature has reported inconsistent and confusing results. In this article, the latest evidence is summarized to explore the optimal endoscopic management of PFC with DPDS.

Current State of Imaging of Pediatric Pancreatitis: AJR Expert Panel Narrative Review.

Pancreatitis is as common in children as it is in adults, though causes and accepted imaging strategies differ in children. In this narrative review we discuss the epidemiology of childhood pancreatitis and key imaging features for pediatric acute, acute recurrent, and chronic pancreatitis. We rely heavily on our collective experience in discussing advantages and disadvantages of different imaging modalities; practical tips for optimization of ultrasound, CT, and MRI with MRCP in children; and image interpretation pearls. Challenges and considerations unique to imaging pediatric pancreatitis are discussed, including timing of imaging, role of secretin-enhanced MRCP, utility of urgent MRI, severity prediction, autoimmune pancreatitis, and best methods for serial imaging. We suggest a methodical approach to pancreatic MRI interpretation in children and have included a sample structured report, and we provide consensus statements according to our experience imaging children with pancreatitis.

Secretin-Enhanced MRCP: How and Why-AJR Expert Panel Narrative Review.

Secretin-enhanced MRCP (S-MRCP) has advantages over standard MRCP for imaging of the pancreaticobiliary tree. Through the use of secretin to induce fluid production from the pancreas and leveraging of fluid-sensitive MRCP sequences, S-MRCP facilitates visualization of ductal anatomy, and the findings provide insight into pancreatic function, allowing radiologists to provide additional insight into a range of pancreatic conditions. This narrative review provides detailed information on the practical implementation of S-MRCP, including patient preparation, logistics of secretin administration, and dynamic secretin-enhanced MRCP acquisition. Also discussed are radiologists' interpretation and reporting of S-MRCP examinations, including assessments of dynamic compliance of the main pancreatic duct and of duodenal fluid volume. Established indications for S-MRCP include pancreas divisum, anomalous pancreaticobiliary junction, Santorinicele, Wirsungocele, chronic pancreatitis, main pancreatic duct stenosis, and assessment of complex postoperative anatomy. Equivocal or controversial indications are also described along with an approach to such indications. These indications include acute and recurrent acute pancreatitis, pancreatic exocrine function, sphincter of Oddi dysfunction, and pancreatic neoplasms.

EUS is superior to secretin-enhanced cholangio-MRI to establish the etiology of idiopathic acute pancreatitis.

Background and study aims The etiology of idiopathic acute pancreatitis (IAP) should always be defined. Our aim was to compare the diagnostic value of endoscopic ultrasound (EUS) versus secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) in patients with IAP. Patients and Methods Patients admitted to a single tertiary care University hospital with IAP were invited to participate in the study. Enrolled patients underwent EUS and S-MRCP in a single-blinded comparative study. EUS and S-MRCP were performed no sooner than 4 weeks after discharge. The diagnostic yield of EUS and S-MRCP and demographic variables were included in the analysis. Additional follow-up, results of subsequent serology, radiographic exams, and relevant histological analysis were considered in determination of the final diagnosis. Results A total of 34 patients were enrolled; EUS was normal in six, cholelithiasis was defined in 15, choledocholithiasis in two, pancreas divisum in three, branch-type intraductal papillary mucinous tumor (IPMT) in three, and chronic pancreatitis in five. S-MRCP identified choledocholithiasis in one, divisum in four, branch-type IPMT in three, chronic pancreatitis in two; 24 subjects diagnosed as normal by S-MRCP. Diagnostic correlation between EUS and S-MRCP was slight (kappa = 0.236, 95 % confidence interval: 0.055–0.416). EUS provided a statistically significantly higher diagnostic yield than S-MRCP: 79.4 % (CI95 %: 65 %–94 %) vs 29.4 % (CI95 %: 13 %–46 %) (P = 0.0002). The sensitivity, specificity, and positive and negative predictive values of EUS and S-MRCP were 90 %, 80 %, 96 %, 57 % and 33 %, 100 %, 100 % and 16 %, respectively. Conclusion The diagnostic yield of EUS is higher than S-MRCP in patients with IAP.

Secretin-Enhanced Magnetic Resonance Cholangiopancreatography - A Reliable Approach to Assess Exocrine Pancreatic Function?

Objectives: To investigate the relation between exocrine pancreatic function and secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP) fluid volumes and its concordance to pancreatic elastase using a case-control approach. Methods: Navigator-triggered T2-weighted 3D-turbo-spin-echo sMRCP was performed on a 1·5-T-system in 977 subjects including volunteers without a history of pancreatitis (group: A n=917) and chronic pancreatic disorder patients without (group: B, n=32) and with diagnosis of exocrine pancreatic insufficiency (EPI) (group: C, n=28). After intravenous administration of 1 unit/kg secretin duodenal filling was graded (0-3) and quantified as sMRCP fluid volume. According to pancreatic elastase ELISA subjects were grouped as severe (<100 μg/g) and moderate (100-200 μg/g) pancreatic elastase insufficiency (PEI). Statistic evaluation comprised Kruskal-Wallis Test, multinomial logistic, linear regression and area-under-the-curve (AUC) analysis. Findings: sMRCP fluid volume was lower in patients with pancreatic disorders compared to controls (P=0·001), but independent of the presence of PEI. The odds ratio of a reduced grading of duodenal filling was higher in patients with EPI (group: C compared to controls) (P=0·001) but not significantly different between controls and patients without EPI (group: B P=0·911) or between both patient groups (group: B versus group: C P=0·059). There was only a small association of sMRCP fluid volume with pancreatic elastase (R2=0·04,P=0·001). AUCs of sMRCP fluid volume were 0·967 (95%CI 0·950-0·985) to detect EPI and 0·581 (95% CI 0·471-0·691) to detect severe PEI. Interpretation: Static sMRCP allows assessment of exocrine pancreatic function and can differentiate patients with diagnosis of EPI from volunteers, but is not suitable for screening of patients with PEI because of its discordance to pancreatic elastase. Funding Statement: The work is part of the Community Medicine Research net, which was funded by following institutions: Federal Ministry of Education and Research (grants 01ZZ9603, 01ZZ0103, 01ZZ0403, 01ZZ0701, 03ZIK012), Ministry of Cultural Affairs as well as the Social Ministry of the Federal State of Mecklenburg-West Pomerania, Federal Ministry of Nutrition, Agriculture and Consumer’s Safety (07HS003), German Research Foundation (projects Gr 1912/5-1, Ko 799/5-1, Vo 955/5-1, Vo 955/6-1, Vo 955/10-1), Competence Network Heart Failure (01GI0205), Competence Network Diabetes (01GI0855), German Asthma and COPD Network (COSYCONET; BMBF 01GI0883), Genopathomik (BMBF FZK 03138010), Alfried Krupp von Bohlen und Halbach Foundation, Alexander v. Humboldt Foundation, Leibniz Society, Siemens AG, Health Care Sector (Erlangen, Germany), Pfizer Pharma GmbH (SBU Endocrinology and Ophthalmology; Berlin Germany), Novo Nordisk (Mainz, Germany), Data Input GmbH (Darmstadt, Germany), GABA International AG (Therwil, Switzerland), Imedos Systems (Jena, Germany) and Heinen and Lowenstein (Bad Ems, Germany). Declaration of Interests: There are no conflicts of financial interest. Ethics Approval Statement: The local ethics committee approved the SHIP study, and written informed consent was obtained from all participating subjects before study inclusion.

Quantitative pancreatic MRI: a pathology-based review.

MRI plays an important role in the clinical management of pancreatic disorders and interpretation is reliant on qualitative assessment of anatomy. Conventional sequences capturing pancreatic structure can however be adapted to yield quantitative measures which provide more diagnostic information, with a view to increasing diagnostic accuracy, improving patient stratification, providing robust non-invasive outcome measures for therapeutic trials and ultimately personalizing patient care. In this review, we evaluate the use of established techniques such as secretin-enhanced MR cholangiopancreatography, diffusion-weighted imaging, T 1, T 2* and fat fraction mapping, but also more experimental methods such as MR elastography and arterial spin labelling, and their application to the assessment of diffuse pancreatic disease (including chronic, acute and autoimmune pancreatitis/IgG4 disease, metabolic disease and iron deposition disorders) and cystic/solid focal pancreatic masses. Finally, we explore some of the broader challenges to their implementation and future directions in this promising area.

Jejunal response to secretin is independent of the pancreatic response in secretin-enhanced magnetic resonance cholangiopancreatography

PurposeTo investigate whether jejunal secretions are independent of the pancreatic response to secretin in secretin-enhanced Magnetic Resonance Cholangiopancreatography (s-MRCP) examination of subjects with and without chronic pancreatitis (CP). MethodsPatients were identified through a search of s-MRCP examinations performed between 2014–2016 (n = 513) as well as the multidisciplinary pancreatitis clinic registry (n = 586). Fifty cases with CP (based on M-ANNHEIM criteria) and 50 matched controls were selected. Signal intensity changes after secretin administration (˜1–5 min’ post-secretin response) in three locations were assessed: second portion of the duodenum (D2), third/fourth portions of the duodenum (D3-4), and the jejunum. The post-secretin response was compared between (cases vs. controls) and within the study groups. ResultsThere was a significantly lower 1–5 min’ post-secretin response among CP patients in D2 (all p-values <0.01). However, no significant difference in 1–5 min’ post-secretin response was detected in the jejunum. Minute-by-minute analysis of the post-secretin response showed a significant increase up to the 5th minute only in D2 of the control group. The post-secretin response in the jejunum was significant after 1 min but was similar among patients with CP and controls. CP was a significant determinant of post-secretin response in D2 but not in the jejunum. ConclusionsEarly post-secretin response at jejunum is independent of the pancreatic response that can be detected at D2, and should not be misinterpreted as a rapid pancreatic response. Therefore, pancreatic function on s-MRCP should be assessed by the presence of fluid in D2 and not jejunum.

The clinical value of secretin-enhanced MRCP in the functional and morphological assessment of pancreatic diseases.

Secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) provides a non-invasive way, with which, to evaluate pancreatic duct (PD) anatomy and exocrine pancreatic function. S-MRCP can be added to the routine pancreas MR examination in equivocal cases. Moreover, it can detect subtle PD involvement, allowing diagnosis of early, rather than end-stage, pancreatic diseases. Although S-MRCP is a valuable non-invasive diagnostic method, it is only performed in a few centres due to relative high cost. Furthermore, less familiarity with its indications, the examination technique, and image interpretation also contribute to its limited use. Thus, the purpose of this article is to explain secretin's mechanism of action, the examination technique, the clinically relevant indications, the advantages, and limitations. Finally, we will focus on image analysis and its role in achieving an early and accurate diagnosis of specific pancreatic and PD diseases.

Automatic gallbladder segmentation using combined 2D and 3D shape features to perform volumetric analysis in native and secretin-enhanced MRCP sequences.

We aimed to develop the first fully automated 3D gallbladder segmentation approach to perform volumetric analysis in volume data of magnetic resonance (MR) cholangiopancreatography (MRCP) sequences. Volumetric gallbladder analysis is performed for non-contrast-enhanced and secretin-enhanced MRCP sequences. Native and secretin-enhanced MRCP volume data were produced with a 1.5-T MR system. Images of coronal maximum intensity projections (MIP) are used to automatically compute 2D characteristic shape features of the gallbladder in the MIP images. A gallbladder shape space is generated to derive 3D gallbladder shape features, which are then combined with 2D gallbladder shape features in a support vector machine approach to detect gallbladder regions in MRCP volume data. A region-based level set approach is used for fine segmentation. Volumetric analysis is performed for both sequences to calculate gallbladder volume differences between both sequences. The approach presented achieves segmentation results with mean Dice coefficients of 0.917 in non-contrast-enhanced sequences and 0.904 in secretin-enhanced sequences. This is the first approach developed to detect and segment gallbladders in MR-based volume data automatically in both sequences. It can be used to perform gallbladder volume determination in epidemiological studies and to detect abnormal gallbladder volumes or shapes. The positive volume differences between both sequences may indicate the quantity of the pancreatobiliary reflux.

Secretin-Enhanced Magnetic Resonance Cholangiopancreatography for Assessing Pancreatic Secretory Function in Children

To assess the accuracy and interrater reproducibility of measurements of pancreatic secretory function by magnetic resonance cholangiopancreatography in response to secretin administration and to describe our experience using the technique to noninvasively assess pancreatic secretory function in a pediatric population. In the accuracy study, phantoms with varying fluid volume (47-206 mL) were imaged using the clinical quantification sequence. Fluid volume was measured by image segmentation (ImageJ). Measurement accuracy was expressed in terms of error (absolute and percent) relative to known fluid volume. In the reproducibility study and clinical experience, 31 patients with suspected pancreatic disease underwent 33 secretin-enhanced magnetic resonance cholangiopancreatography exams. Two-dimensional T2-weighted, fat-saturated single shot fast spin echo sequences were acquired before and after secretin injection (0.2 µg/kg, max 16 µg). Secreted fluid volume (postsecretin minus presecretin) was independently measured by 2 blinded reviewers. Between reviewer measurement reproducibility was assessed based on correlation (Spearman) and bias (Bland-Altman analysis). For the accuracy study, fluid volumes were measured with mean volume errors of -0.3 to +12.5 mL (percent error -0.03% to +9.0%). For the reproducibility study, the mean secreted fluid volumes measured by reviewer 1 and reviewer 2 were 79.1 ± 54.3 mL (range 5.5-215.4) and 77.2 ± 47.1 mL (range 6.7-198.1 mL), respectively. Measured secreted fluid volumes were very strongly correlated (r = 0.922) between reviewers with a bias of only 1.9 mL (95% limits of agreement -40.5 to 44.2). Measurement of fluid volume by magnetic resonance imaging is highly accurate with <10% (<13 mL) error in measured volume. Measurements of pancreatic secreted fluid volume in response to secretin by magnetic resonance cholangiopancreatography are highly reproducible with a bias of <2 mL between reviewers.

A study of the clinical utility of a 20-minute secretin-stimulated endoscopic pancreas function test and performance according to clinical variables

Direct pancreas juice testing of bicarbonate, lipase, or trypsin after stimulation by secretin or cholecystokinin is used to determine exocrine function, a surrogate for diagnosing chronic pancreatitis (CP). Endoscopic pancreas function tests (ePFTs), where a peak bicarbonate concentration (PBC)≥80 mEq/L in pancreas juice is considered normal, are now used more frequently. In this ePFT, aspirates start 35 minutes after secretin administration because pancreas output peaks 30 minutes after secretagogue administration. The performance of ePFT in a cohort of patients with a presumptive diagnosis of CP referred to a pancreas clinic for consideration of an intervention including total pancreatectomy and islet autotransplantation was studied, compared with EUS, ERCP, histology, and consensus diagnosis. The effect of sedation, narcotic use, aspirate volume, body mass index, age, and proton pump inhibitors (PPIs) on test performance is reported. After a test dose, synthetic human secretin was administered intravenously, and 30 minutes later sedation was achieved with midazolam and fentanyl or propofol. A gastroscope was advanced to the major papilla where 4 continuous aspiration samples were performed at 5-minute intervals in sealed bottles. PBC≥80 mEq/L was normal. Eighty-one patients had ePFTs from August 2010 through October 2015. Twenty-seven patients (33%) were diagnosed with CP. Eighteen of the 27 patients with CP and 1 of the 54 patients without CP had an abnormal ePFT, producing a sensitivity of 66% (95% CI, 46.0-83.5), specificity 98% (95% CI, 90.1-99.9), positive predictive value 94.7% (95% CI, 74-99.9), and negative predictive value 85.5% (95% CI, 74.2-93.1). ERCP and PBC concordance was generally poor, but none of the patients without CP had major EUS changes, and only 3 patients with a PBC<80 mEq/L had a normal EUS. The PBC was affected by narcotics and PPI use. A 20-minute ePFT after secretin administration had a marginal sensitivity for diagnosis of CP. The diagnosis of CP should not rely on a single study and certainly not a PFT. The duodenal aspirate volume did not correlate with the PBC, which contrasts with current secretin-enhanced MRCP knowledge; therefore, further studies on this subject are warranted. Neither type of sedation, BMI, nor age affected test performance. Narcotics and PPIs may affect the PBC, so borderline results should be interpreted with caution in these groups.

Low Alcohol and Cigarette Use Is Associated to the Risk of Developing Chronic Pancreatitis.

The aim of this study was to investigate the contribution of smoking and alcohol intake and pancreas divisum on the risk of developing chronic pancreatitis (CP). Consecutive patients with CP who underwent secretin-enhanced magnetic resonance cholangiopancreatography were compared with consecutive patients without pancreatic disease who underwent secretin-enhanced magnetic resonance cholangiopancreatography for irritable bowel syndrome. We enrolled 145 consecutive CP patients and 103 irritable bowel syndrome patients from 2010 to 2014. In a univariate analysis, statistically significant differences in sex, mean age, and the duration and amount of cigarette and alcohol use were found. Per a receiver operating characteristic curve analysis, thresholds for cigarette and alcohol consumption were, respectively, 5.5 cigarettes and 13.5 g daily. In a multivariate analysis, independent risk factors for CP were male sex (odds ratio [OR], 2.05), smoking more than 5.5 cigarettes per day (OR, 2.72), and drinking more than 13.5 g/d (OR, 6.35). In an Italian population, we confirmed smoking and alcohol as cofactors in the development of CP. This study shows that alcohol intake and smoking habits are 2 of the most important risk factors for the development of CP.

The Value of Secretin-Enhanced MRCP in Patients With Recurrent Acute Pancreatitis.

The purpose of this study is to assess the additional value of secretin-enhanced MRCP over conventional (non-secretin-enhanced) MRCP in diagnosing disease in patients with recurrent acute pancreatitis. A retrospective review of a radiology database found 72 patients with recurrent acute pancreatitis who had secretin-enhanced MRCP and ERCP correlation within 3 months of each other between January 2007 and December 2011. Of these patients, 54 had no history of pancreatic tumor or surgery and underwent MRI more than 3 months after an episode of acute pancreatitis. In addition, 57 age- and sex-matched control subjects with secretin-enhanced MRCP and ERCP correlation and without a diagnosis of recurrent acute pancreatitis or chronic pancreatitis were enrolled as the control group. All studies were anonymized, and secretin-enhanced MRCP images (image set A) were separated from conventional 2D and 3D MRCP and T2-weighted images (image set B). Image sets A and B for each patient were assigned different and randomized case numbers. Two blinded reviewers independently assessed both image sets for ductal abnormalities and group A image sets for exocrine response to secretin. There were statistically significantly more patients with recurrent acute pancreatitis with reduced exocrine function compared with patients in the control group (32% vs 9%; p < 0.01) on secretin-enhanced images. Patients with recurrent acute pancreatitis were more likely to have side branch dilation (p = 0.02; odds ratio, 3.6), but not divisum, compared with the control group. Secretin-enhanced images were superior to non-secretin-enhanced images for detecting ductal abnormalities in patients with recurrent acute pancreatitis, with higher sensitivity (76% vs 56%; p = 0.01) and AUC values (0.983 vs 0.760; p < 0.01). Up to one-third of patients with recurrent acute pancreatitis showed exocrine functional abnormalities. Secretin-enhanced MRCP had a significantly higher yield for ductal abnormalities than did conventional MRI and should be part of the MRCP protocol for investigation of patients with recurrent acute pancreatitis.

Pancreatic duct stenosis: Differential diagnosis between malignant and benign conditions at secretin-enhanced MRCP

PurposeTo define imaging criteria of benign and malignant nature in patients with main pancreatic duct (MPD) stenosis. Materials-methodsS-MRCPs of 35 patients with pancreatitis and 14 with adenocarcinoma were evaluated. ResultsAdenocarcinoma caused higher prevalence of complete stenosis (14/14–100% vs 17/35–49%), dilated side-branches (14/14–100% vs 18/35–51%) and lower prevalence of duct-penetrating sign (0/14–0% vs 31/35–89%). The number of stenoses was higher in benign conditions (mean 1.4 Vs 1). Upstream MPD diameter was higher in cancer-induced stenoses (4.5 vs 2.9mm). ConclusionsSingle complete stenosis with dilated side branches, increased MPD caliber and absent duct-penetrating sign are suggestive of malignancy.

Detection of exocrine dysfunction by MRI in patients with early chronic pancreatitis.

To determine if T1-weighted MR signal of the pancreas can be used to detect early CP. A retrospective analysis was performed on 51 suspected CP patients, who had both secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) and an intraductal secretin stimulation test (IDST). There were 29 patients in normal and 22 patients in the low bicarbonate group. Bicarbonate level, total pancreatic juice volume, and excretory flow rate were recorded during IDST. Signal intensity ratio of pancreas (SIR), fat signal fraction, pancreatograms findings, and grade of duodenal filling were recorded on S-MRCP by two blinded radiologists. There was a significant difference in the signal intensity ratio of the pancreas to spleen (SIRp/s) between the normal and low bicarbonate groups (p<0.0001). A significant positive correlation was found between pancreatic fluid bicarbonate level and SIRp/s (p<0.0001). SIRp/s of 1.2 yielded sensitivity of 77% and specificity of 83% for detection of pancreatic exocrine dysfunction (AUC: 0.89). T1-weighted MR signal of the pancreas has a high sensitivity and specificity for the detection of parenchymal abnormalities related to exocrine dysfunction and can therefore be helpful in evaluation of suspected early CP.

Smaller Width of the Pancreatic Duct During Secretin-Enhanced Magnetic Resonance Cholangiopancreatography in Pancreatic-Sufficient Cystic Fibrosis Patients.

New tools are needed in cystic fibrosis (CF) diagnostics in pancreatic-sufficient CF (PS-CF) patients. Secretin-enhanced magnetic resonance cholangiopancreatography (SE-MRCP) allows for improved assessment of the width of the pancreatic duct. Sixteen PS-CF patients and 17 healthy volunteers underwent SE-MRCP. The width of the pancreatic duct in the head, the body, and the tail of the pancreas was measured at the baseline and 1, 2, 3, 5, and 10 minutes after secretin administration. The width of the pancreatic duct in the head of the pancreas did not differ between the groups at the baseline; after 10 minutes of secretin stimulation, it was smaller in PS-CF patients (median, 1.4 mm [first-third quartile, 1.3-2.0] vs 2.2 mm [1.7-2.4], P = 0.008). The area under the curve for discrimination between the 2 groups using this parameter was 0.77 (95% confidence interval, 0.60-0.93). The SE-MRCP identified differences in the width of the pancreatic duct between PS-CF and healthy volunteers. Further improvements of the method are needed to augment its clinical utility.

T1 mapping for diagnosis of mild chronic pancreatitis.

To determine if the T1 relaxation time of the pancreas can detect parenchymal changes in mild chronic pancreatitis (CP). This Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study analyzed 98 patients with suspected mild CP. Patients were grouped as normal (n = 53) or mild CP (n = 45) based on history, presenting symptomatology, and concordant findings on both the secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) and endoscopic retrograde cholangiopancreatography (ERCP). T1 maps were obtained in all patients using the same 3D gradient echo technique on the same 3T scanner. T1 relaxation times, fat signal fraction (FSF), and anterior-posterior (AP) diameter were correlated with the clinical diagnosis of CP. There was a significant difference (P < 0.0001) in the T1 relaxation times between the control (mean = 797 msec, 95% confidence interval [CI]: 730, 865) and mild CP group (mean = 1099 msec, 95% CI: 1032, 1166). A T1 relaxation time threshold value of 900 msec was 80% sensitive (95% CI: 65, 90) and 69% specific (95% CI: 56, 82) for the diagnosis of mild CP (area under the curve [AUC]: 0.81). Multiple regression analysis showed that T1 relaxation time was the only statistically significant variable correlating with the diagnosis of CP (P < 0.0001). T1 relaxation times showed a weak positive correlation with the pancreatic FSF (ρ = 0.33, P = 0.01) in the control group, but not in the mild CP group. The T1 relaxation time of the pancreatic parenchyma was significantly increased in patients with mild CP. Therefore, T1 mapping might be used as a practical quantitative imaging technique for the evaluation of suspected mild CP. 3 J. Magn. Reson. Imaging 2017;45:1171-1176.

Secretin-enhanced MR Imaging of the Pancreas.

Secretin is a hormone that stimulates the exocrine pancreatic secretion of bicarbonate-rich fluid from the acinar cells of the pancreas that accumulates within the pancreatic ductal lumen. The exogenous administration of secretin improves the visualization of pancreatic ducts at magnetic resonance (MR) cholangiopancreatography (MRCP), because of an enlargement of the pancreatic duct system and an increase of the fluid content within the lumen of the pancreatic ducts, responsible of an increase of MR signal. In this review, the technique of secretin-enhanced MRCP, which has the aim to depict the whole pancreatic duct system, the biliary tree, the major and minor papillae, and the duodenum, will be described. Because of the anatomic contiguity between the pancreas and the gastrointestinal tract, the presence of fluid within the stomach may overlap with the pancreatic duct system and therefore the pancreatic duct may be difficult to visualize, representing a potential source of diagnostic pitfalls. The technique to reduce the signal intensity of the static fluid present within the stomach and in the duodenal lumen is also described. The technique of secretin administration will be illustrated, with emphasis on the synchronization of secretin administration and MR image acquisition. Furthermore, the frequency and number of MRCP images necessary to achieve a temporal resolution adequate to visualize the physiologic changes in the pancreatic gland, induced by the administration of secretin, is described. The assessment of pancreatic, morphologic, and functional response to the administration of secretin, as depicted on MRCP images, will be illustrated. Finally, the indications for secretin-enhanced MRCP will be discussed to define which patients will benefit from secretin-enhanced MR imaging for their treatment planning. (©) RSNA, 2016.