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

Magnetic Resonance Cholangiopancreatography vs Endoscopy Retrograde Cholangiopancreatography for Detection of Anatomic Variants of the Pancreatic Duct in Children

OBJECTIVE

To compare the efficacy of magnetic resonance cholangiopancreatography (MRCP) with endoscopy retrograde cholangiopancreatography (ERCP) in children for the identification of pancreatic duct variants.

STUDY DESIGN

We identified children with a pancreatic duct variant by ERCP and separately queried our MRCP database for similar variants. Patients with a paired ERCP-MRCP were reviewed. Three radiologists blinded to the ERCP and MRCP findings were asked to independently review the MRCP studies and define the pancreatic duct anatomy. These blinded reviewers also graded the magnetic resonance imaging examination quality.

RESULTS

Seventy-four pairs of ERCP-MRCP examinations were identified. Pancreas divisum was the most frequent ductal variant encountered (73%). There was fair agreement between the radiology reviewers as to the quality of the magnetic resonance imaging studies (Fleiss Kappa agreement). Concordance of the reviewers with that of the ERCP was moderate for the exact diagnosis, moderate for the presence of pancreas divisum, and fair for agreement on the presence of any duct variant. Concordance among reviewers was moderate for the exact diagnosis, moderate for normal vs abnormal, and substantial for the presence of pancreas divisum.

CONCLUSIONS

Diagnostic limitations exist when comparing MRCP with the gold reference standard of ERCP, specifically when assessing for pancreatic duct variants in children.

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.

Wirsungocele: evaluation by MRCP and clinical significance

PURPOSE

Wirsungocele is a rare cystic dilatation of the main pancreatic duct seen at the terminal portion of the duct of Wirsung. The purpose of our study is to evaluate the diagnostic value of MRCP in detection of Wirsungocele and the association between the MRCP-determined size of Wirsungocele and the MRCP-clinical findings of pancreatitis.

METHODS

Thirty-four patients with reported 'Wirsungocele' were analyzed in the study. Two radiologists reviewed MRCP/S-MRCP images for the presence and diameter of Wirsungocele (WD), main pancreatic duct dilatation (MPDD), side branch ectasia (SBE), acinarization, and duodenal filling grade. Electronic medical record review included symptoms (abdominal pain), signs (recurrent acute/chronic pancreatitis), and select laboratory testing (serum amylase and lipase). Inter-reader agreement values were calculated by ICC. Pearson correlation analysis was performed to evaluate the association of WD with radiological and clinical findings. The comparison of WD on MRCP versus S-MRCP was calculated by Wilcoxon test. Mann-Whitney U test was used for two independent variable comparisons.

RESULTS

The sensitivity of MRCP for the detection of Wirsungocele calculated using the S-MRCP and ERCP as the reference method was 76.9% and 100%, respectively. There was a significant difference in the diameter of Wirsungocele measured by MRCP vs S-MRCP (p < 0.001). There was good inter-reader agreement for the detection of Wirsungocele on MRCP and measurement of WD on MRCP and S-MRCP (ICC: 0.79, 0.89, and 0.80, respectively, p < 0.001). There was a significant difference in WD between the patients with and without MPDD (p < 0.05). There was a significant positive correlation between WD and MPDD (r = 0.66, p < 0.05). WD was significantly associated with recurrent acute pancreatitis (p < 0.05).

CONCLUSION

MRCP is a highly sensitive and non-invasive imaging tool for detection of Wirsungocele. Greater Wirsungocele diameter is associated with MPDD and recurrent acute pancreatitis.

Diagnostic clues, pitfalls, and imaging characteristics of '-celes' that arise in abdominal and pelvic structures

'-Celes' is an ancient Greek language suffix that means 'tumor,' 'hernia,' 'swelling,' or 'cavity.' There are many '-celes' in the abdomen and pelvis that may be encountered during routine imaging interpretation, including santorinicele, choledochocele, ureterocele, lymphocele, mucocele, rectocele, cystocele, peritoneocele, varicocele, spermatocele, hydrocele, hematocele, pyocele and syringocele. Most '-celes' are detected incidentally at imaging for other clinical indications, but some deserve more attention due to a range of clinical symptoms or functional disorder that can adversely affect patient quality of life. The objective of this article was to address all of the '-celes' that a general radiologist and abdominal radiologist should know and be able to recognize. Imaging characteristics, diagnostic clues, and pitfalls have been provided to improve diagnostic accuracy and patient outcomes.

Chronic pancreatitis: an overview of diagnosis and management

INTRODUCTION

Chronic pancreatitis entails a heavy burden on the healthcare system because of its often protracted evolution, requiring complex diagnostic and therapeutic procedures.

AREAS COVERED

This review focuses on novel imaging and endoscopic diagnostic and therapeutic interventions that have changed the management of patients with chronic pancreatitis. We have conducted an extensive search of original papers and guidelines, in order to provide a comprehensive and up to date review of available evidence in these areas of interest.

EXPERT OPINION

The traditional challenges in managing chronic pancreatitis patients stemmed from the limitations of diagnostic modalities, which could not correctly identify patients in an early stage of the disease, as well as from the scarcity of therapeutic options available. Advances in imaging of CT-scan, MRI, and EUS have opened the way for early diagnosis and staging. This has allowed more aggressive and tailored therapeutic modalities, particularly in endoscopic therapy and minimally invasive surgical interventions. Although high-quality data from large RCTs is still scarce, evidence-based algorithms for diagnosis and therapy are now changing the way we address this chronic disease. In the near future, we can expect a tailored approach based on patient and disease-related predictive factors, relying on a vast armamentarium of endoscopic and surgical solutions.

Advanced MR Imaging of the Pancreas

MR imaging can be optimized to evaluate a spectrum of pancreatic disorders with advanced sequences aimed to provide quantitative results and increase MR diagnostic capabilities. The pancreas remains a challenging organ to image because of its small size and location deep within the body. Besides its anatomic limitations, pancreatic pathology can be difficult to identify in the early stages. For example, subtle changes in ductal anatomy and parenchymal composition seen in early chronic pancreatitis are imperceptible with other modalities, such as computed tomography. This article reviews the application of MR imaging techniques and emerging MR sequences used in pancreas imaging.

Magnetic resonance cholangiopancreatography findings in early chronic pancreatitis diagnosed according to the Japanese Diagnostic Criteria

OBJECTIVES

It is important for diagnosing early chronic pancreatitis (CP), which may be improved by therapeutic intervention. We aimed to examine the pancreatic ductal changes on magnetic resonance cholangiopancreatography (MRCP) in patients with early CP defined by the Japanese Diagnostic Criteria.

METHODS

This retrospective study included patients suspected early CP and performed both endoscopic ultrasonography (EUS) and MRCP from January 2010 to August 2018. We assessed the diameter of the main pancreatic duct (MPD) and the number of irregularly dilated duct branches using MRCP imaging in early CP.

RESULTS

We enrolled 165 patients and 25 patients (15%) fulfilled the diagnostic criteria for early CP. Irregular dilatation of ≥ 3 duct branches on MRCP was more often observed in early CP compared to non-early CP (P = 0.004), although MPD diameter was comparable (2.06 mm in early CP vs. 1.96 in non-early CP, P = 0.698). The sensitivity and specificity were 45% and 74%, respectively. The prevalence of positive MRCP findings in patients with ≥ 2 positive EUS findings was higher than that in patients with 1 positive EUS finding (P = 0.08) and in patients without an EUS finding (P < 0.001). There was no difference in the average diameter of MPD.

CONCLUSION

Patients with early CP often exhibit alteration in duct branches and not in MPD in addition to parenchymal alteration. Both pancreatic parenchyma and duct branches might need to be evaluated by EUS and MRCP.

Clinical importance of main pancreatic duct variants and possible correlation with pancreatic diseases

Background: Except for pancreas divisum (PD), the prevalence of anatomic variants of the main pancreatic duct (MPD) seems to be insufficiently investigated. To date, their role in the occurrence of pancreatic exocrine insufficiency (PEI) and morphological changes suggestive of chronic pancreatitis (CP) has remained unclear.Methods: A systematic review was performed, searching MEDLINE and Web of Science, limited to articles published between 1960 and 1 June 2019.Results: Our review included a total number of 3234 subjects. The most common variant of MPD was type 3, followed by type 1, indicating MPD drainage pattern into major papilla (MP) as the most frequent. A sub-variant of type 3, known as 'reverse pancreas divisum' had a prevalence of 2.2%. Type 4 variant- PD, was found in 6.4% of all cases. The most common sub-variant of PD was complete PD, followed by incomplete PD and variant with MPD as only pancreatic duct. Type 5 variant (including ansa pancreatica) was present in 2.9% of subjects. Apart from one study with a significantly higher frequency of morphological changes suggestive of CP in patients with ansa pancreatica, the studies stated no significant association between pancreatic disease and MPD variants. Furthermore, only one study examined the influence of MPD variants on exocrine pancreatic function. Although equivocal, this association is most likely found to be insignificant.Conclusion: To elucidate linkage between MPD variants and the occurrence of chronic pancreatitis and impairment of pancreatic exocrine function, further clinical investigations are warranted.

Advanced imaging techniques for chronic pancreatitis

MRI and MRCP play an important role in the diagnosis of chronic pancreatitis (CP) by imaging pancreatic parenchyma and ducts. MRI/MRCP is more widely used than computed tomography (CT) for mild to moderate CP due to its increased sensitivity for pancreatic ductal and gland changes; however, it does not detect the calcifications seen in advanced CP. Quantitative MR imaging offers potential advantages over conventional qualitative imaging, including simplicity of analysis, quantitative and population-based comparisons, and more direct interpretation of detected changes. These techniques may provide quantitative metrics for determining the presence and severity of acinar cell loss and aid in the diagnosis of chronic pancreatitis. Given the fact that the parenchymal changes of CP precede the ductal involvement, there would be a significant benefit from developing MRI/MRCP-based, more robust diagnostic criteria combining ductal and parenchymal findings. Among cross-sectional imaging modalities, multi-detector CT (MDCT) has been a cornerstone for evaluating chronic pancreatitis (CP) since it is ubiquitous, assesses primary disease process, identifies complications like pseudocyst or vascular thrombosis with high sensitivity and specificity, guides therapeutic management decisions, and provides images with isotropic resolution within seconds. Conventional MDCT has certain limitations and is reserved to provide predominantly morphological (e.g., calcifications, organ size) rather than functional information. The emerging applications of radiomics and artificial intelligence are poised to extend the current capabilities of MDCT. In this review article, we will review advanced imaging techniques by MRI, MRCP, CT, and ultrasound.

Accuracy of a novel noninvasive secretin-enhanced MRCP severity index scoring system for diagnosis of chronic pancreatitis: correlation with EUS-based Rosemont criteria

PURPOSE

To evaluate the accuracy of a secretin-enhanced MRCP Chronic Pancreatitis Severity Index (CPSI) in the diagnosis of chronic pancreatitis (CP) based on endoscopic ultrasound (EUS) Rosemont criteria.

METHODS

In this retrospective study, 31 patients (20 women; median age 48 years, range 18-77) with known/suspected CP evaluated with both EUS and secretin-enhanced MRCP were included. CP severity was graded using a ten-point-scale secretin-enhanced MRCP-based CPSI scoring system which considered ductal, parenchymal and secretin-based dynamic abnormalities. Cases were categorized as normal, mild, moderate or severe CP. Correlation between CPSI and the EUS Rosemont criteria was performed using Cohen's kappa coefficient. Comparative evaluation of test performance was obtained using ROC analysis.

RESULTS

Using EUS Rosemont criteria, eight patients had features consistent/suggestive of CP, 20 patients were normal and three were indeterminate. On CPSI, five patients were normal, 12 had mild and 14 had moderate/severe CP. There was only fair agreement (k = 0.272) between CPSI and Rosemont criteria categories. CPSI showed 87.5% sensitivity, 69.6% specificity and 74.2% accuracy (cutoff value = 3.5 points; area under the curve = 0.804; p = 0.0026) for CP diagnosis based on EUS Rosemont criteria.

CONCLUSION

CPSI showed relatively high diagnostic accuracy for diagnosis of CP based on Rosemont criteria. The CPSI scoring system can be proposed as a noninvasive alternative to the EUS Rosemont criteria for CP diagnosis.

ACG Clinical Guideline: Chronic Pancreatitis

Chronic pancreatitis (CP) is historically defined as an irreversible inflammatory condition of the pancreas leading to varying degrees of exocrine and endocrine dysfunction. Recently however, the paradigm for the diagnosis has changed in that it breaks with the traditional clinicopathologic-based definition of disease, focusing instead on diagnosing the underlying pathologic process early in the disease course and managing the syndrome more holistically to change the natural course of disease and minimize adverse disease effects. Currently, the most accepted mechanistically derived definition of CP is a pathologic fibroinflammatory syndrome of the pancreas in individuals with genetic, environmental, and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress. The most common symptom of CP is abdominal pain, with other symptoms such as exocrine pancreatic insufficiency and diabetes developing at highly variable rates. CP is most commonly caused by toxins such as alcohol or tobacco use, genetic polymorphisms, and recurrent attacks of acute pancreatitis, although no history of acute pancreatitis is seen in many patients. Diagnosis is made usually on cross-sectional imaging, with modalities such as endoscopic ultrasonography and pancreatic function tests playing a secondary role. Total pancreatectomy represents the only known cure for CP, although difficulty in patient selection and the complications inherent to this intervention make it usually an unattractive option. This guideline will provide an evidence-based practical approach to the diagnosis and management of CP for the general gastroenterologist.

Diagnosis and Management of Chronic Pancreatitis: A Review

IMPORTANCE

Chronic pancreatitis (CP) is a chronic inflammatory and fibrotic disease of the pancreas with a prevalence of 42 to 73 per 100 000 adults in the United States.

OBSERVATIONS

Both genetic and environmental factors are thought to contribute to the pathogenesis of CP. Environmental factors associated with CP include alcohol abuse (odds ratio [OR], 3.1; 95% CI, 1.87-5.14) for 5 or more drinks per day vs abstainers and light drinkers as well as smoking (OR, 4.59; 95% CI, 2.91-7.25) for more than 35 pack-years in a case-control study involving 971 participants. Between 28% to 80% of patients are classified as having "idiopathic CP." Up to 50% of these individuals have mutations of the trypsin inhibitor gene (SPINK1) or the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Approximately 1% of people diagnosed with CP may have hereditary pancreatitis, associated with cationic trypsinogen (PRSS1) gene mutations. Approximately 80% of people with CP present with recurrent or chronic upper abdominal pain. Long-term sequelae include diabetes in 38% to 40% and exocrine insufficiency in 30% to 48%. The diagnosis is based on pancreatic calcifications, ductal dilatation, and atrophy visualized by imaging with computed tomography, magnetic resonance imaging, or both. Endoscopic ultrasound can assist in making the diagnosis in patients with a high index of suspicion such as recurrent episodes of acute pancreatitis when imaging is normal or equivocal. The first line of therapy consists of advice to discontinue use of alcohol and smoking and taking analgesic agents (nonsteroidal anti-inflammatory drugs and weak opioids such as tramadol). A trial of pancreatic enzymes and antioxidants (a combination of multivitamins, selenium, and methionine) can control symptoms in up to 50% of patients. Patients with pancreatic ductal obstruction due to stones, stricture, or both may benefit from ductal drainage via endoscopic retrograde cholangiopancreatography (ERCP) or surgical drainage procedures, such as pancreaticojejunostomy with or without pancreatic head resection, which may provide better pain relief among people who do not respond to endoscopic therapy.

CONCLUSIONS AND RELEVANCE

Chronic pancreatitis often results in chronic abdominal pain and is most commonly caused by excessive alcohol use, smoking, or genetic mutations. Treatment consists primarily of alcohol and smoking cessation, pain control, replacement of pancreatic insufficiency, or mechanical drainage of obstructed pancreatic ducts for some patients.

Advanced MR Imaging Techniques for Pancreas Imaging

Advances in MR imaging with optimization of hardware, software, and techniques have allowed for an increased role of MR in the identification and characterization of pancreatic disorders. Diffusion-weighted imaging improves the detection and staging of pancreatic neoplasms and aides in the evaluation of acute, chronic and autoimmune pancreatitis. The use of secretin-enhanced MR cholangiography improves the detection of morphologic ductal anomalies, and assists in the characterization of pancreatic cystic lesions and evaluation of acute and chronic pancreatitis. Emerging MR techniques such as MR perfusion, T1 mapping/relaxometry, and MR elastography show promise in further evaluating pancreatic diseases.

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

PURPOSE

To 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).

METHODS

Patients 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.

RESULTS

There 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.

CONCLUSIONS

Early 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.

Reporting Standards for Chronic Pancreatitis by Using CT, MRI, and MR Cholangiopancreatography: The Consortium for the Study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer

Chronic pancreatitis is an inflammatory condition of the pancreas with clinical manifestations ranging from abdominal pain, acute pancreatitis, exocrine and/or endocrine dysfunction, and pancreatic cancer. There is a need for longitudinal studies in well-phenotyped patients to ascertain the utility of cross-sectional imaging findings of chronic pancreatitis for diagnosis and assessment of disease severity. CT and MR cholangiopancreatography are the most common cross-sectional imaging studies performed for the evaluation of chronic pancreatitis. Currently, there are no universal reporting standards for chronic pancreatitis. Several features of chronic pancreatitis are applied clinically, such as calcifications, parenchymal T1 signal changes, focal or diffuse gland atrophy, or irregular contour of the gland. Such findings have not been incorporated into standardized diagnostic criteria. There is also lack of consensus on quantification of disease severity in chronic pancreatitis, other than by using ductal features alone as described in the Cambridge classification. The Consortium for the Study of Chronic Pancreatitis, Diabetes, and Pancreatic Cancer (CPDPC) was established by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Cancer Institute in 2015 to undertake collaborative studies on chronic pancreatitis, diabetes mellitus, and pancreatic adenocarcinoma. CPDPC investigators from the Adult Chronic Pancreatitis Working Group were tasked with development of a new consensus approach to reporting features of chronic pancreatitis aimed to standardize diagnosis and assessment of disease severity for clinical trials. This consensus statement presents and defines features of chronic pancreatitis along with recommended reporting metrics. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Megibow in this issue.

Guidelines for the Diagnostic Cross Sectional Imaging and Severity Scoring of Chronic Pancreatitis

The paper presents the international guidelines for imaging evaluation of chronic pancreatitis. The following consensus was obtained: Computed tomography (CT) is often the most appropriate initial imaging modality for evaluation of patients with suspected chronic pancreatitis (CP) depicting most changes in pancreatic morphology. CT is also indicated to exclude other potential intraabdominal pathologies presenting with symptoms similar to CP. However, CT cannot exclude a diagnosis of CP nor can it be used to exclusively diagnose early or mild disease. Here magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP) is superior and is indicated especially in patients where no specific pathological changes are seen on CT. Secretin-stimulated MRCP is more accurate than standard MRCP in the depiction of subtle ductal changes. It should be performed after a negative MRCP, when there is still clinical suspicion of CP. Endoscopic ultrasound (EUS) can also be used to diagnose parenchymal and ductal changes mainly during the early stage of the disease. No validated radiological severity scoring systems for CP are available, although a modified Cambridge Classification has been used for MRCP. There is an unmet need for development of a new and validated radiological CP severity scoring system based on imaging criteria including glandular volume loss, ductal changes, parenchymal calcifications and parenchymal fibrosis based on CT and/or MRI. Secretin-stimulated MRCP in addition, can provide assessment of exocrine function and ductal compliance. An algorithm is presented, where these imaging parameters can be incorporated together with clinical findings in the classification and severity grading of CP.

Comparison of EUS with MRCP in idiopathic acute pancreatitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Idiopathic acute pancreatitis (IAP) poses a diagnostic challenge for gastroenterologists, because confirmation of the disease etiology has important implications for the selection of the best possible treatment and the prevention of possible recurrence or the development of chronic pancreatitis (CP). ERCP, EUS, and MRCP typically are used to diagnose IAP when conventional radiologic methods fail. However, their exact role in the diagnosis of IAP has not yet been determined.

METHODS

We searched the PubMed, EMBASE, OVID, Cochrane Library (including CENTRAL), China National Knowledge Infrastructure (CNKI), and Wanfang databases from inception to April 2017. Studies involving the use of EUS and/or MRCP for the etiologic diagnosis of IAP were included. A meta-analysis was performed by using Review Manager Version 5.2 for comparative studies and R software 3.3.3 to determine diagnostic yield of the studies.

RESULTS

Among the 34 studies that met the inclusion criteria (n = 2338), 7 studies used a combination of EUS and MRCP and totaled 249 patients. The results comparing EUS with MRCP showed a diagnostic yield of 153 of the 239 patients (64%) in the EUS group, which was higher than the yield of 82 of 238 patients (34%) in the MRCP group (P < .001) in the 7 studies, and the diagnostic yield was 60% in the EUS group, 24% in the MRCP group, and 43% in the MRCP after secretin stimulation (S-MRCP) group. In our subgroup analysis of CP and biliary disease, EUS was superior to MRCP (P < .001), but when comparing the efficacy of the modalities in the diagnosis of pancreatic divisum, S-MRCP was obviously superior to MRCP and EUS (12% vs 2% vs 2%).

CONCLUSION

EUS and MRCP should both be used in the diagnostic work-up of IAP as complementary techniques. EUS had a higher diagnostic accuracy than MRCP (64% vs 34%) in the etiologic diagnosis of IAP and should be preferred for establishing a possible biliary disease and CP diagnosis, whereas S-MRCP was superior to EUS and MRCP in diagnosing a possible anatomic alteration in the biliopancreatic duct system, such as pancreatic divisum.

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.

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

BACKGROUND AND AIMS

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Total pancreatectomy for recurrent acute and chronic pancreatitis: a critical review of patient selection criteria

PURPOSE OF REVIEW

Critical review of the indications for total pancreatectomy and highlight limitations in current diagnostic criteria for chronic pancreatitis.

RECENT FINDINGS

The diagnosis of noncalcific chronic pancreatitis remains controversial because of an overreliance on nonspecific imaging and laboratories findings. Endoscopic ultrasound, s-magnetic resonance cholangiopancreatography, and/or endoscopic pancreatic function testing are often used to diagnose noncalcific chronic pancreatitis despite the fact that there is no gold standard for this condition. Abdominal pain is not specific for chronic pancreatitis and is more likely to be encountered in patients with functional gastrointestinal disorders based on the high incidence of these conditions. The duration of pain and opioid analgesic use results in central sensitization that adversely affects pain outcomes after total pancreatectomy. An alcoholic cause is associated with poorer pain outcomes after total pancreatectomy.

SUMMARY

The lack of a gold standard for noncalcific chronic pancreatitis limits the diagnostic accuracy of imaging and laboratory tests. The pain of chronic pancreatitis is nonspecific and is affected by duration, preoperative opioid use, and cause. These factors will need to be considered in the development of future selection criteria for this morbid surgery.

Diagnostic Accuracy of Transabdominal Ultrasound in Chronic Pancreatitis

The performance of transabdominal ultrasound (US) in chronic pancreatitis (CP) following the advances in US technology made during recent decades has not been explored. Our aim in this prospective study was to evaluate the diagnostic accuracy of modern abdominal US compared with the Mayo score in CP. One hundred thirty-four patients referred for suspected CP were included in the study. Fifty-four patients were assigned the diagnosis CP. After inclusion, transabdominal US was performed. Ductal features (calculi, dilations and caliber variations, side-branch dilations and hyper-echoic duct wall margins) and parenchymal features (calcifications, cysts, hyper-echoic foci, stranding, lobulation and honeycombing) were recorded. Features were counted and scored according to a weighting system defined at the international consensus meeting in Rosemont, Illinois (Rosemont score). Diagnostic performance indices (95% confidence interval) of US were calculated: The unweighted count of features had a sensitivity of 0.69 (0.54-0.80) and specificity of 0.97 (0.90-1). The Rosemont score had a sensitivity of 0.81 (0.69-0.91) and specificity of 0.97 (0.90-1). Exocrine pancreatic failure was most pronounced in Rosemont groups I and II (p < 0.001). We conclude that using both unweighted and weighted scores, the diagnostic accuracy of modern transabdominal US is good. The extent of pancreatic changes detected by the method is correlated with exocrine pancreatic function.

Endoscopic Ultrasonography May Select Subjects Having Asymptomatic Chronic Pancreatic Hyperenzymemia Who Require a Stricter Follow-up

OBJECTIVES

We have previously shown that at least 50% of patients with asymptomatic chronic pancreatic hyperenzymemia (ACPH) may develop morphological pancreatic alterations. Endoscopic ultrasonography (EUS) may detect small lesions, and its sensitivity seems to be higher than other imaging techniques. The aim of this study was to evaluate whether EUS may modify the management of patients having ACPH.

METHODS

In 2 referral centers for pancreatic disease, a retrospective analysis of prospectively enrolled patients with ACPH was conducted.

RESULTS

Seventy-three patients with ACPH were enrolled for the purpose of this study. Endoscopic ultrasonography was performed as the last examination in 45 subjects who resulted negative at previous imaging studies (abdominal ultrasound, computed tomography, magnetic resonance imaging associated with cholangiopancreatography). Using EUS in 7 subjects, abnormalities were found in the following: 3 branch-duct intraductal papillary mucinous neoplasms, 1 duodenal diverticulum, 1 annular pancreas, 1 findings suggestive of chronic pancreatitis, and 1 undefined cyst (<5 mm).

CONCLUSIONS

Endoscopic ultrasonography is able to detect alteration not found by other imaging technique in 15.5% of patients with ACPH and may be useful to select those patients who require a more strict follow-up.

Efficacy of Endoscopic Minor Papilla Sphincterotomy for Symptomatic Santorinicele

BACKGROUND & AIMS

Santorinicele, a rare focal cystic dilation of the distal portion of the dorsal pancreatic duct at the minor papilla, can be a cause of recurrent acute pancreatitis (RAP). Endoscopic minor papilla sphincterotomy (EMPS) has been evaluated as a treatment in case reports but never systematically investigated.

METHODS

We performed a retrospective analysis of the efficacy of EMPS in reducing episodes of pancreatitis. We collected data on 30 patients with santorinicele and RAP who underwent EMPS from June 2009 through April 2015 at University Hospital of Verona in Italy. The mean follow-up period was 43.8 months.

RESULTS

The average number of pancreatitis episodes per year before EMPS was 1.59 vs 0.18 episodes after EMPS; the average number of pancreatitis cases that occurred during a comparable time period before EMPS was 2.63 vs 0.67 cases after EMPS (P < .0001). Complete responses to EMPS (no recurrence of pancreatitis) were reported for 80% of patients. Six patients relapsed after a mean time of 16 months. Five patients were found to have a potential cause of RAP beyond santorinicele (2 patients had post-sphincterotomy stenosis, 1 patient was a chronic consumer of alcohol, 1 patient had a mutation in the CFTR gene, and 1 patient had a side-branch intraductal papillary mucinous neoplasm).

CONCLUSIONS

EMPS is effective in reducing the incidence of pancreatitis in patients with santorinicele.

Pancreatitis in Children

Pancreatic disease in children has a wide clinical spectrum and may present as Acute pancreatitis (AP), Acute recurrent pancreatitis (ARP), Chronic pancreatitis (CP) and Pancreatic disease without pancreatitis. This article highlights the etiopathogenesis and management of pancreatitis in children along with clinical data from five tertiary care hospitals in south India [Chennai (3), Cochin and Pune].

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

PURPOSE

To define imaging criteria of benign and malignant nature in patients with main pancreatic duct (MPD) stenosis.

MATERIALS-METHODS

S-MRCPs of 35 patients with pancreatitis and 14 with adenocarcinoma were evaluated.

RESULTS

Adenocarcinoma 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).

CONCLUSIONS

Single complete stenosis with dilated side branches, increased MPD caliber and absent duct-penetrating sign are suggestive of malignancy.

The Accuracies of Diagnosing Pancreas Divisum by Magnetic Resonance Cholangiopancreatography and Endoscopic Ultrasound: A Systematic Review and Meta-analysis

Magnetic resonance cholangiopancreatography (MRCP), MRCP after secretin stimulation (S-MRCP) and endoscopic ultrasonography (EUS) are all selected to diagnose pancreas divisum. However, the accuracies of three diagnosis remain unclear. The aim is to address the diagnostic accuracies of MRCP, S-MRCP and EUS on pancreas divisum. We searched PubMed, MEDLINE and EMBASE databases from inception to January, 2015. Of the 536 citations retrieved, 16 studies were included. For MRCP diagnosis on pancreas divisum, the area under the hierarchical summary receiver-operating characteristic (HSROC) curve was 0.90 (95% confidence interval [CI] 0.87 to 0.92), and for S-MRCP and EUS, 0.99 (95% CI 0.97 to 0.99) and 0.97 (95% CI 0.96 to 0.98). Sensitivity and specificity for MRCP were 0.59 (95% CI 0.45 to 0.71) and 0.99 (95% CI 0.96 to 1.00); for S-MRCP, 0.83 (95% CI 0.66 to 0.92) and 0.99 (95% CI 0.96 to 1.00); for EUS, 0.85 (95% CI 0.67 to 0.94) and 0.97 (95% CI 0.90 to 0.99). Comprehensive comparison of three diagnostic techniques to pancreas divisum, S-MRCP was more reliable than MRCP and EUS on the effect of the diagnostic test.

MRCP Versus ERCP in the Evaluation of Chronic Pancreatitis in Children: Which Is the Better Choice?

OBJECTIVES

To evaluate the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) in the detection of chronic pancreatitis (CP)-specific changes in the pediatric population.

METHODS

The study included 48 children with pancreatic disorders subjected to both endoscopic retrograde cholangiopancreatography (ERCP) and MRCP within a 1- to 4-month interval. The sensitivity, specificity, positive predictive value, and negative predictive value of MRCP in the detection of CP-specific changes were determined using ERCP as a diagnostic standard.

RESULTS

Diagnostic ERCP pancreatograms were obtained in 41 (85.4%) of 48 patients and diagnostic MRCP images in all 48 children. The sensitivity and positive predictive value of MRCP were 77.1% and 90%, respectively, and its specificity and negative predictive value amounted to 50% and 27.3%, respectively. The patients with consistent results of MRCP and ERCP (ie, true-positive and true-negative cases) and individuals with incompatible results of the tests (ie, false-positive and false-negative cases) differed in terms of their median age at MRCP (14.17 vs 10.33 years) and median CP stage according to the Cambridge Scale (4 vs 2).

CONCLUSIONS

Magnetic resonance cholangiopancreatography provides diagnostic information equivalent to ERCP in a large percentage of pediatric patients with CP and should be used as the imaging method of choice, especially if the likelihood of therapeutic intervention is low.

Secretin-Stimulated Magnetic Resonance Imaging Assessment of the Benign Pancreatic Disorders: Systematic Review and Proposal for a Standardized Protocol

This systemic review summarizes the current literature and general consensus on secretin-stimulated magnetic resonance imaging (s-MRI) of the benign pancreatic disorders and discusses important aspects on how s-MRI is optimally performed. The aim is to provide an overview, for clinicians and radiologist, of the s-MRI protocols and the range of clinical applications. Furthermore, the review will summarize the criteria for evaluation of pancreatic morphology and function based on s-MRI.The literature search indentified 69 original articles and 15 reviews. Chronic pancreatitis was the disease that was most frequently assessed by s-MRI (33%), followed by acute pancreatitis (9%). Dynamic thick-slab 2-dimensional magnetic resonance cholangiopancreatography was the most used imaging sequence (86%). The diameter of the main pancreatic duct (75%) and pancreatic exocrine function based on visual grading of duodenal filling (67%) were the most evaluated pancreatic features. Sufficient similarities between studies were identified to propose the most agreeable standardized s-MRI protocol for morphological and functional assessment of the pancreas. In the future, more research and increased collaboration between centers is necessary to achieve more consensus and optimization of s-MRI protocols.

Diagnostic Performance of Contrast-Enhanced MRI With Secretin-Stimulated MRCP for Non-Calcific Chronic Pancreatitis: A Comparison With Histopathology

OBJECTIVES

Diagnosis of non-calcific chronic pancreatitis (NCCP) in patients presenting with chronic abdominal pain is challenging and controversial. Contrast-enhanced magnetic resonance imaging (MRI) with secretin-stimulated MRCP (sMRCP) offers a safe and noninvasive modality to diagnose mild CP, but its findings have not been correlated with histopathology. We aimed to assess the correlation of a spectrum of MRI/sMRCP findings with surgical histopathology in a cohort of NCCP patients undergoing total pancreatectomy with islet autotransplantation (TPIAT).

METHODS

Adult patients undergoing TPIAT for NCCP between 2008 and 2013 were identified from our institution's surgery database and were included if they had MRI/sMRCP within a year before surgery. Histology was obtained from resected pancreas at the time of TPIAT by wedge biopsy of head, body, and tail, and was graded by a gastrointestinal pathologist who was blinded to the imaging features. A fibrosis score (FS) of 2 or more was considered as abnormal, with FS ≥6 as severe fibrosis. A multivariate regression analysis was performed for MRI features predicting fibrosis, after taking age, sex, smoking, alcohol, and body mass index (BMI) into consideration. A quantitative receiver operating characteristic (ROC) curve analysis was performed and Spearman rank correlation coefficient (r) was calculated.

RESULTS

Fifty-seven patients (females=49, males=8) with NCCP and MRI/sMRCP were identified. ROC curve analysis showed that two or more MRI/sMRCP features provided the best balance of sensitivity (65%), specificity (89%), and accuracy (68%) to differentiate abnormal (FS≥2) from normal pancreatic tissue. Two or more features provided the best cutoff (sensitivity 88%, specificity 78%) for predicting severe fibrosis (FS≥6). There was a significant correlation between the number of features and severity of fibrosis (r=0.6, P<0.0001). A linear regression after taking age, smoking, and BMI into consideration showed that main pancreatic duct irregularity, T1-weighted signal intensity ratio between pancreas and paraspinal muscle, and duodenal filling after secretin injection to be significant independent predictors of fibrosis.

CONCLUSIONS

A strong correlation exists between MRI/sMRCP findings and histopathology of NCCP.

Evaluation of Qualitative Magnetic Resonance Imaging Features for Diagnosis of Chronic Pancreatitis

OBJECTIVES

The purpose of this study was to determine qualitative pancreatic magnetic resonance imaging (MRI) features that must be present to predict abnormal pancreatic secretory function in patients evaluated for chronic pancreatitis (CP).

METHODS

The MRIs of study subjects were reviewed by 2 abdominal radiologists; qualitative parenchyma and ductal features were recorded. Endoscopic pancreatic function test (ePFT) results (reference standard) were classified as normal (peak pancreatic fluid bicarbonate [HCO3-] ≥75 meq/L) or abnormal (<75). Abnormal ePFT was further classified as mild/moderate (74-65) and marked deficiency (<65). Statistical analysis was performed to assess the association between MRI features and abnormal ePFT.

RESULTS

The study cohort was composed of 93 subjects, mean age 49 years (range, 18-78 years), 65% females. Univariate analysis identified 9 qualitative MRI features significantly (P < 0.05) associated with abnormal pancreatic secretory function. Number of MRI features increases as peak pancreatic fluid [HCO3-] decreases (Pearson r = -0.629; P = 0.001). Receiver operating characteristic curve analysis determined that a threshold of 6 or more associated MRI features 64% sensitive and 94% specific for marked bicarbonate deficiency.

CONCLUSIONS

Qualitative MRI parenchymal and ductal features are associated with CP. Presence of 6 or more features results in a higher specificity for the diagnosis of CP in advanced disease.

ESPGHAN and NASPGHAN Report on the Assessment of Exocrine Pancreatic Function and Pancreatitis in Children

The purpose of this clinical report is to discuss several recent advances in assessing exocrine pancreatic insufficiency (EPI) and pancreatitis in children, to review the array of pancreatic function tests, to provide an update on the inherited causes of EPI, with special emphasis on newly available genetic testing, and to review newer methods for evaluating pancreatitis.

Noninvasive investigation of exocrine pancreatic function: Feasibility of cine dynamic MRCP with a spatially selective inversion-recovery pulse

PURPOSE

To investigate the feasibility of noncontrast-enhanced cine dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatially selective inversion-recovery (IR) pulse for evaluating exocrine pancreatic function in comparison with the N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA) test as a pancreatic exocrine function test.

MATERIALS AND METHODS

Twenty subjects with or without chronic pancreatitis were included. MRCP with a spatially selective IR pulse was repeated every 15 seconds for 5 minutes to acquire a total of 20 images (cine-dynamic MRCP). The median and mean frequency of the observation (the number of times) and the moving distance (mean secretion grading scores) of pancreatic juice inflow on cine-dynamic MRCP were compared with a BT-PABA test.

RESULTS

The urinary PABA excretion rate (%) had significant positive correlations with both the mean secretion grade (r = 0.66, P = 0.002) and frequency of secretory inflow (r = 0.62, P = 0.004) in cine dynamic MRCP. Both the mean frequency of observations of pancreatic secretory inflow (1.4 ± 1.6 times vs. 14.3 ± 4.2 times, P < 0.001) and the mean secretion grade (grade = 0.16 ± 0.24 vs. grade = 1.81 ± 0.81, P < 0.001) was significantly lower in the chronic pancreatitis group than in the normal subject group.

CONCLUSION

Cine dynamic MRCP with a spatially selective IR pulse may have potential for estimating the pancreatic exocrine function noninvasively as a substitute for the BT-PABA test.

Anatomic variants of the pancreatic duct and their clinical relevance: an MR-guided study in the general population

OBJECTIVES

To investigate the frequency of pancreatic duct (PD) variants and their effect on pancreatic exocrine function in a population-based study using non-invasive secretin-stimulated magnetic resonance cholangiopancreatography (sMRCP).

METHODS

Nine hundred and ninety-five volunteers, 457 women and 538 men, aged 51.9 ± 13.4 years, underwent navigator-triggered, T2-weighted, 3D turbo spin echo MRCP on a 1.5 T system after 1 unit/kg secretin administration. Two readers evaluated images for PD variants. Pancreatic exocrine function and morphological signs of chronic pancreatitis such as abnormalities of the main PD, side branch dilatation, and pancreatic cysts were evaluated and related to PD variants using a Kruskal-Wallis test and post hoc analysis.

RESULTS

Of all sMRCP, 93.2% were of diagnostic quality. Interobserver reliability for detection of PD variants was found to be kappa 0.752 (95 %CI, 0.733 - 0.771). Normal PD variants were observed in 90.4% (n = 838/927). Variants of pancreas divisum was identified in 9.6% (n = 89/927). Abnormalities of the main PD, side branch dilatation, and pancreatic cysts were observed in 2.4%, 16.6%, and 27.7%, respectively, and were not significantly different between pancreas divisum and non-divisum group (P = 0.122; P = 0.152; P = 0.741). There was no association between PD variants and pancreatic exocrine function (P = 0.367).

CONCLUSION

PD variants including pancreas divisum are not associated with morphological signs of chronic pancreatitis or restriction of pancreatic exocrine function.

KEY POINTS

MRCP allows the evaluation of pancreatic duct variants and morphological change. Pancreatic duct variants are not associated with morphological signs of chronic pancreatitis. Pancreas divisum is not accompanied by restriction of pancreatic exocrine function. Pancreatic duct variants including pancreas divisum are limited in their clinical relevance.

Secretin-enhanced MR cholangiopancreatography: spectrum of findings

Magnetic resonance cholangiopancreatography (MRCP) is the most effective, safe, noninvasive magnetic resonance (MR) imaging technique for the evaluation of the pancreaticobiliary ductal system. The MRCP imaging technique has substantially improved during the past 2 decades and is based mainly on the acquisition of heavily T2-weighted MR images, with variants of fast spin-echo sequences. MRCP can also be performed by utilizing the hormone secretin, which stimulates a normal pancreas to secrete a significant amount of fluid while transiently increasing the tone of the sphincter of Oddi. The transient increase in the diameter of the pancreatic duct improves the depiction of the ductal anatomy, which can be useful in patients in whom detailed evaluation of the pancreatic duct is most desired because of a suspicion of pancreatic disease. Improved depiction of the ductal anatomy can be important in (a) the differentiation of side-branch intraductal papillary mucinous neoplasms from other cystic neoplasms and (b) the diagnosis and classification of chronic pancreatitis, the disconnected pancreatic duct syndrome, and ductal anomalies such as anomalous pancreaticobiliary junction and pancreas divisum. In patients examined after pancreatectomy, stimulation with secretin can give information about the patency of the pancreaticoenteric anastomosis. Duodenal filling during the secretin-enhanced phase of the MRCP examination can be used to estimate the excretory reserve of the pancreas. Secretin is well tolerated, and complications are rarely seen. Secretin-enhanced MRCP is most useful in (a) the evaluation of acute and chronic pancreatitis, congenital variants of the pancreaticoduodenal junction, and intraductal papillary mucinous neoplasms and (b) follow-up of patients after pancreatectomy.

Secretin-stimulated MRCP in volunteers: assessment of safety, duct visualization, and pancreatic exocrine function

OBJECTIVE

The objective of our study was to investigate secretin-stimulated MRCP in terms of the safety of secretin, improvement of duct visualization, and assessment of pancreatic exocrine function.

MATERIALS AND METHODS

Eight hundred sixteen volunteers (370 women and 446 men; mean age, 49.7 ± 13.1 [SD] years) underwent 3D MRCP before and after secretin stimulation (1 U/kg of body weight) at 1.5 T. For the first 2 hours after secretin injection, subjects were evaluated for adverse reactions. Improvement of duct visualization after secretin stimulation was subjectively evaluated by two readers and was quantified by duct diameter measurements. Pancreatic exocrine function was evaluated subjectively by two readers according to the duodenal filling and was quantified using calibrated volumetric measurements of total excreted volume and pancreatic flow output.

RESULTS

Two subjects (0.2%) showed flushing (minor adverse reaction). Duct visualization after secretin injection was improved for reader 1 in 468 (57.4%) and for reader 2 in 478 (58.6%) subjects, was unchanged for reader 1 in 324 (39.7%) and for reader 2 in 315 (38.6%) subjects, and was worse for reader 1 in 24 (2.9%) and reader 2 in 23 (2.8%) subjects (interrater agreement, κ = 0.925). Main pancreatic duct diameters increased significantly after secretin stimulation: pancreatic head, 10.5% (mean); body, 12.5%; and tail, 7.7%. Pancreatic exocrine function evaluated according to assessment of duodenal filling was as follows: grade 0 (restricted function) in 0.7% of subjects by both readers, grade 1 (reduced function) in 4.8% of subjects by reader 1 and 4.5% of subjects by reader 2, grade 2 (low-grade reduced function) in 31.1% of subjects by reader 1 and 26.5% of subjects by reader 2, and grade 3 (physiologic function) in 63.4% of subjects by reader 1 and 68.3% of subjects by reader 2 (interrater agreement, κ = 0.838). The mean total excreted volume was 111.8 ± 49.8 (SD) mL, and the mean pancreatic flow output was 9.6 ± 4.2 mL/min.

CONCLUSION

Secretin-stimulated MRCP moderately improves main pancreatic duct visualization and allows noninvasive quantification of pancreatic exocrine function with a negligible risk of side effects.

MRCP in patient care: a prospective survey of gastroenterologists

OBJECTIVE

MRCP is increasingly used to evaluate pancreaticobiliary disease, yet its effect on patient care is unknown. The purpose of this study was to measure the effect of MRCP on referring physicians' initial diagnoses, the physicians' confidence in their diagnoses, and the influence of MRCP results on clinical management.

SUBJECTS AND METHODS

We prospectively surveyed gastroenterologists who referred patients for nonurgent MRCP for pancreaticobiliary evaluation. Before MRCP, gastroenterologists reported the working diagnosis, confidence level (high, moderate, low), and next step in clinical management if MRCP was unavailable. MRCP was performed with standard protocols, including secretin enhancement. After reviewing MRCP findings and without referring to their previous assessment, gastroenterologists reported a revised diagnosis, confidence level, and next step in clinical management. They then compared pre- and post-MRCP management plans and rated the influence of MRCP on changing management from 1 (none) to 5 (major). Diagnostic confidence and frequency of common diagnoses and recommendation for an invasive next-step procedure (e.g., ERCP) or endoscopic ultrasound were compared between pre- and post-MRCP assessments.

RESULTS

Survey data were analyzed on 171 patients (123 women, 48 men; mean age, 50 [SD, 17] years; range, 19-88 years) undergoing MRCP for unexplained abdominal pain (42.9%), suspected pancreaticobiliary neoplasm (20%), recent acute (17.1%) or suspected chronic (14.9%) pancreatitis, and other indications (5.1%). Recommendations of ERCP and endoscopic ultrasound decreased after MRCP (from 49.1% to 35.1%, p=0.03, and from 26.9% to 13.5%, p≤0.01). After MRCP, high confidence in diagnosis increased (from 72/171 to 100/171, p<0.01), as did recommendations for noninvasive therapy (from 18/171 to 56/171, p<0.01). A major or substantial change in clinical management was made in the care of 67 of 171 patients (39.2%).

CONCLUSION

Use of MRCP significantly changes gastroenterologists' treatment of patients with suspected pancreaticobiliary disease by increasing diagnostic confidence and reducing the frequency of invasive follow-up procedures.

Pancreatic duct patterns in acute pancreatitis: a MRI study

Objectives

To study the MRI findings of the pancreatic duct in patients with acute pancreatitis.

Materials and Methods

A total of 239 patients with acute pancreatitis and 125 controls were analyzed in this study. The severity of acute pancreatitis was graded using the MR severity index (MRSI) and the Acute Physiology And Chronic Healthy Evaluation II(APACHE II) scoring systems. The number of main pancreatic duct (MPD) segments visualized, and both MPD diameter and pancreatic duct disruption were noted and compared with the severity of acute pancreatitis.

Results

The frequency of MPD segment visualization in the control group was higher than that in the acute pancreatitis group (p<0.05). The number of MPD segments visualized was negatively correlated with the MRSI score (p<0.05) and the APACHE II score (p<0.05). There was no difference in the MPD diameter between the acute pancreatitis and control groups or among the patients with different severities of acute pancreatitis (p>0.05). The prevalence of pancreatic duct disruption was 7.9% in the acute pancreatitis group. The prevalences of pancreatic duct disruption were 4.8% and 15.3% in the mild and severe acute pancreatitis groups based on the APACHE II score, respectively, and were 0%, 5.7% and 43.5% in the mild, moderate and severe acute pancreatitis groups according the MRSI score, respectively. The prevalence of pancreatic duct disruption was correlated with the severity of acute pancreatitis based on the APACHE II score (p<0.05) and MRSI score (p<0.05).

Conclusion

The pancreatic duct in acute pancreatitis patients was of normal diameter. The number of MPD segments visualized and visible pancreatic duct disruption on MRI may be supplementary indicators for determining the severity of acute pancreatitis.

Does secretin add value in pediatric magnetic resonance cholangiopancreatography?

BACKGROUND

Secretin--a hormone that stimulates pancreatic exocrine secretion--is described to improve visualization of the pancreatic duct by magnetic resonance cholangiopancreatography (MRCP). In our pediatric practice, however, we have not observed substantial benefit with the use of secretin.

OBJECTIVE

To determine whether secretin dilates and improves visualization of the pancreatic duct in pediatric MRCP.

MATERIALS AND METHODS

Retrospective evaluation of secretin-enhanced MRCPs performed over a 15-month period. One reviewer measured the pancreatic duct pre- and post-secretin and two reviewers, blinded to the administration of secretin, assessed image quality and subjective duct visibility. Similar assessments of the biliary tree served as internal controls.

RESULTS

We reviewed 20 MRCPs in 17 children. Following secretin administration, there was a small (0.3 mm) but statistically significant increase in pancreatic duct diameter (P = 0.002) and small (<0.2 mm) but significant increase in intrahepatic bile duct diameter (P = 0.0104). On subjective review, there was no significant difference in image quality or duct visibility based on the administration of secretin.

CONCLUSION

Secretin induces dilatation of the pancreatic duct but the value of that effect in pediatric MRCP is suspect given the small change in duct diameter and the lack of improvement in image quality and duct visibility.

Role of secretin-enhanced magnetic resonance cholangiopancreatography in the evaluation of patients following pancreatojejunostomy

Objective:

This study was conducted to assess the role of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) in the evaluation of patients following pancreatico-jejunal anatomosis.

Materials and Methods:

S-MRCP studies (n = 83) performed at Brigham and Women's Hospital between 1/2005 and 7/2005 were retrospectively reviewed. Among these, there were 13 patients (10 females, 3 males; mean age = 45 years, range = 18-74 years) who were evaluated with S-MRCP following pancreatojejunal anatomosis. Single-shot fast spin-echo T2-weighted thick slab dynamic MRCP images obtained before and every minute (for 10 min) after IV injection of secretin (2 mcg/kg body weight of SecreFloTM IV over 1 min) were reviewed retrospectively and independently by 3 readers. Image analysis included measurement of the main pancreatic duct (MPD) diameter and subjective assessment of the grade of visualization of the MPD remnant. The amount of jejunal fluid and visualization of the pancreatico-jejunal anatomosis pre-and post-secretin were also documented. Direct correlation with endoscopic retrograde cholangiopancreatography (ERCP) finding was available in six of the 13 cases.

Results:

The MPD diameter and MPD remnant visualization improved post-secretin for 1/3 readers. The number of pancreatico-jejunal anastomoses and the amount of jejunal fillings pre-and post-secretin was seen to improve significantly for 1 of the 3 readers. For Reader 1, the mean MPD diameter in the body of the pancreas, on the pre-and post-secretin image, was 3.2 ± 1.3 mm and 3.8 ± 1.9 mm, respectively. There was no statistical difference in the values pre- and post-secretin in the MPD diameter (P = 0.07), MPD visualization (P = 0.16) and the number of pancreatico-jejunal anastomoses seen (P = 0.125 5/13 pre- and 9/13 post-secretin). Statistical significance was seen in the amount of jejunal filling (P = 0.01) after secretin. For Reader 2, the MPD diameter pre-and post-secretin was 4 ± 2 and 3.9 ± 2.1 mm, respectively (P = 0.89). The MPD visualization (P = 0.19) and degree of jejunal filling (P = 0.7) did not improve significantly. There were 3/13 pancreatico-jejunostomy anastomoses seen pre- and 8/13 seen post-secretin (P = 0.06). The values for Reader 3 reached a statistical significance for the measurement of MPD (P = 0.032). In addition, MPD visualization (P = 0.038), the number of anastomoses seen (P = 0.016) and jejunal filling (P = 0.006) were also significantly improved.

Conclusion:

The addition of intravenous secretin to an MRCP study in the evaluation of patients following pancreatojejunal anastomosis does not significantly impact the visualization of the pancreatic duct. However, secretin may improve the assessment of the pancreatico-jejunal anastomosis.

Anomalies, anatomic variants, and sources of diagnostic pitfalls in pancreatic imaging

In this review, a brief discussion of the important events of pancreatic embryology is followed by presentation of congenital anomalies and normal variants. For each variant, the appearance at different radiologic modalities including computed tomography, magnetic resonance (MR) imaging, endoscopic retrograde cholangiopancreatography, MR cholangiopancreatography, and fluoroscopy will be demonstrated.

Magnetic resonance (MR) imaging and MR cholangiopancreatography findings in cats with cholangitis and pancreatitis

Cholangiohepatitis/cholangitis is second only to hepatic lipidosis as the most common liver disease in cats and is often associated with concurrent pancreatitis. Magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP) have developed into an accurate, highly sensitive and specific imaging tool for the diagnosis of biliary and pancreatic duct disorders in humans. In this prospective case series, 10 cats with suspected cholangitis and/or pancreatitis were enrolled based on clinical history, physical examination and appropriate diagnostic test results. MRI and MRCP sequences with secretin stimulation of the cranial abdomen were performed, and sonography and laparoscopic biopsies for histologic diagnosis were obtained for comparison. MRI detected pancreatic abnormalities in cats suspected of pancreatitis, including T1 pre-contrast hypointense and T2 hyperintense pancreatic parenchyma and a dilated pancreatic duct. The MRI findings of the liver were non-specific. Nine of 10 cats had biliary abnormalities, including gall bladder wall thickening, gall bladder wall moderate contrast enhancement and/or gall bladder debris. Eight of 10 cats had histologic evidence of pancreatitis, as well as hepatitis or cholangitis, with one cat diagnosed with hepatic lymphoma. The advantages of MRI/MRCP over sonography of these cats included the striking pancreatic signal changes associated with pancreatitis and the ability to comprehensibly assess and measure the pancreas and hepatobiliary structures without operator dependence or interference from bowel gas. MRI/MRCP imaging of the feline abdomen may be beneficial in cases with equivocal ultrasound imaging findings.

Pancreaticobiliary disorders: comparison between magnetic resonance cholangiopancreatography images before and after fentanyl injection

OBJECTIVE

This study was designed to determine the effects of intravenous fentanyl on magnetic resonance cholangiopancreatography image quality in the treatment of pancreaticobiliary disorders.

MATERIALS AND METHODS

Forty consecutive patients referred for the evaluation of pancreaticobiliary disorders underwent magnetic resonance cholangiopancreatography in the coronal and oblique-coronal planes before and after fentanyl injection (every 2 up to 9 min). The images were analyzed qualitatively and quantitatively. Diameter and signal intensity were measured at the widest point and distal to the common bile duct and main pancreatic duct.

RESULTS

The mean common bile duct diameters at the widest and distal points and mean pancreatic duct diameter were measured 7.53, 4.72, and 2.14 and 8.33, 5.35, and 2.57 before and after fentanyl injection, respectively. Mean signal intensity at the widest and distal point of the common bile duct and mean pancreatic duct signal intensity measured 278, 199, and 113 and 296, 218, and 121 before and after fentanyl injection, respectively. Minor improvements in image quality were detected qualitatively.

CONCLUSION

Fentanyl injection improves images qualitatively and quantitatively. In agreement with previous studies, our results confirm the beneficial effects of fentanyl as a simple adjunct to traditional magnetic resonance cholangiopancreatography.

Prospective evaluation of subjects with chronic asymptomatic pancreatic hyperenzymemia

OBJECTIVES

Chronic asymptomatic pancreatic hyperenzymemia (CAPH) has been described since 1996 as a benign disease. Recent studies described pathological findings at magnetic resonance cholangiopancreatography with secretin stimulation (s-MRCP) in more than half of the CAPH subjects. The aim of this study was to investigate the frequency and clinical relevance of s-MRCP findings in patients with CAPH.

METHODS

Subjects prospectively enrolled from January 2005 to December 2010 underwent s-MRCP and biochemical tests routinely performed.

RESULTS

Data relative to 160 subjects (94 males, 66 females, age 49.6±13.6 years) were analyzed. In all, 51 (32%) subjects had hyperamylasemia, 9 (6%) hyperlipasemia, and 100 (62%) an increase in both enzyme levels. The time between the first increased dosage of serum pancreatic enzymes and our observation was 3.3±3.9 years (range: 1-15). Familial pancreatic hyperenzymemia was observed in 26 out of 133 subjects (19.5%). Anatomic abnormalities of the pancreatic duct system at s-MRCP were found in 24 out of 160 subjects (15%). Pathological MRCP findings were present in 44 subjects (27.5%) before and in 80 subjects (50%) after secretin administration (P<0.0001). Five subjects (3.1%) underwent surgery, 3 for pancreatic endocrine tumor, 1 for pancreatic adenocarcinoma, and 1 for intraductal papillary-mucinous neoplasia (IPMN) involving the main pancreatic duct, and 18 patients (11.3%) needed a follow-up (17 for IPMN and 1 for endocrine tumor).

CONCLUSIONS

Alterations of the pancreatic duct system at s-MRCP in subjects with CAPH can be observed in 50% of the subjects and are clinically relevant in 14.4% of cases.

Secretin-enhanced MRCP: review of technique and application with proposal for quantification of exocrine function

OBJECTIVE

The purpose of this article is to present a proposal for quantification of exocrine function using secretin-enhanced MRCP for the diagnosis of chronic pancreatitis. The article also reviews the technique and application of secretin-enhanced MRCP in evaluating various pancreatic abnormalities.

SUBJECTS AND METHODS

One hundred thirty-four consecutive patients with chronic abdominal pain undergoing secretin-enhanced MRCP for suspected chronic pancreatitis were included. Patients were divided into four clinical groups (normal, equivocal, early chronic pancreatitis, established pancreatitis) on the basis of clinical symptoms and additional investigations, including CT (n=98), endoscopic pancreatic function test (n=65), endoscopic ultrasound (n=84), and ERCP (n=36). The volume of secretion was obtained by drawing a region of interest around T2 bright fluid secreted on postsecretin HASTE images. The maximal rate of secretion in response to secretin was obtained by plotting change in signal intensity on sequential postsecretin images. The analysis of variance test was used to compare the clinical groups with the volume and rate of secretion.

RESULTS

Significant volume differences were found between the normal and established pancreatitis groups (p<0.0001) as well as the equivocal and established pancreatitis groups (p<0.0005). Marginally significant differences were found between the normal and early pancreatitis groups (p=0.0150) as well as early and established pancreatitis groups (p=0.0351). Differences in the maximal rate of secretion were not statistically significant.

CONCLUSION

Secretory volume measurement of secretin-enhanced MRCP data is a simple method that brings out significant differences between normal, early, and established pancreatitis patients.