Normal pancreatic exocrine function does not exclude MRI/MRCP chronic pancreatitis findings

Management of chronic pancreatitis

Chronic pancreatitis results from repeated episodes of pancreatic inflammation and associated fibrosis leading to the loss of functional exocrine and endocrine pancreatic function. The disease is manifested by abdominal pain, deterioration in quality of life, food maldigestion and malabsorption, diabetes, and an increased risk for pancreatic adenocarcinoma. This review summarizes the latest evidence on the diagnosis and management of chronic pancreatitis and its manifestations. In particular, this review discusses advances in understanding of the role of genetic disorders in the mechanisms of the disease and surgical options for patients refractory to medical therapy. Furthermore, clinical trials are under way to develop medical therapeutics.

T1 signal intensity ratio of the pancreas as an imaging biomarker for the staging of chronic pancreatitis

PURPOSE

Our purpose was to validate the T1 SIR (T1 score) as an imaging biomarker for the staging of CP in a large, multi-institutional, prospective study.

METHODS

The prospective study population included 820 participants enrolled in the PROCEED study from nine clinical centers between June 2017 and December 2021. A radiologist at each institution used a standardized method to measure the T1 signal intensity of the pancreas and the reference organs (spleen, paraspinal muscle, liver), which was used to derive respective T1 scores. Participants were stratified according to the seven mechanistic stages of chronic pancreatitis (MSCP 0-6) based on their clinical history, MRCP, and CT findings.

RESULTS

The mean pancreas-to-spleen T1 score was 1.30 in participants with chronic abdominal pain, 1.22 in those with acute or recurrent acute pancreatitis, and 1.03 in definite CP. After adjusting for covariates, we observed a linear, progressive decline in the pancreas-to-spleen T1 score with increasing MSCP from 0 to 6. The mean pancreas-to-spleen T1 scores were 1.34 (MSCP 0), 1.27 (MSCP 1), 1.21 (MSCP 2), 1.16 (MSCP 3), 1.18 (MSCP 4), 1.12 (MSCP 5), and 1.05 (MSCP 6) (p < 0.0001). The pancreas-to-liver and pancreas-to-muscle T1 scores showed less linear trends and wider confidence intervals.

CONCLUSION

The T1 score calculated by SIR of the pancreas-to-spleen shows a negative linear correlation with the progression of chronic pancreatitis. It holds promise as a practical imaging biomarker in evaluating disease severity in clinical research and practice.

Histopathologic correlation of pancreatic fibrosis with pancreatic magnetic resonance imaging quantitative metrics and Cambridge classification

PURPOSE

To determine the correlation of the T1-weighted signal intensity ratio (T1 SIR, or T1 Score) and arterial-to-delayed venous enhancement ratio (ADV ratio) of the pancreas with pancreatic fibrosis on histopathology.

METHODS

Sixty consecutive adult CP patients who had an MRI/MRCP study prior to pancreatic surgery were analyzed. Three blinded observers measured T1 SIR of pancreas to spleen (T1 SIR p/s), pancreas-to-paraspinal muscle (T1 SIR p/m), ADV ratio, and Cambridge grade. Histopathologic grades were given by a gastrointestinal pathologist using Ammann's fibrosis score. Statistical analysis included Spearman's correlation coefficient of the T1 SIR, ADV ratio, Cambridge grade with the fibrosis score, and weighted kappa for interobserver agreement.

RESULTS

The study population included 31 female and 29 male patients, with an average age of 52.1 (26-78 years). Correlations between fibrosis score and T1 SIR p/s, T1 SIR p/m, and ADV ratio were ρ = - 0.54 (p = 0.0001), ρ = - 0.19 (p = 0.19), and ρ = - 0.39 (p = 0.003), respectively. The correlation of Cambridge grade with fibrosis score was ρ = 0.26 (p = 0.07). There was substantial interobserver agreement (weighted kappa) for T1 SIR p/s (0.78), T1 SIR p/m (0.71), and ADV ratio (0.64). T1 SIR p/s of ≤ 1.20 provided a sensitivity of 74% and specificity of 50% (AUC: 0.74), while ADV ratio of ≤ 1.10 provided a sensitivity of 75% and specificity of 55% (AUC: 0.68) to detect a fibrosis score of ≥ 6.

CONCLUSION

There is a moderate negative correlation between the T1 Score (SIR p/s) and ADV ratio with pancreatic fibrosis and a substantial interobserver agreement. These parenchymal metrics show a higher correlation than the Cambridge grade.

T1 mapping for the diagnosis of early chronic pancreatitis: correlation with Cambridge classification system

OBJECTIVE

This study aims to determine if T1 relaxation time of the pancreas can detect parenchymal changes in early chronic pancreatitis (CP).

METHODS

This study retrospectively analyzed 42 patients grouped as no CP (Cambridge 0; n = 21), equivocal (Cambridge 1; n = 12) or mild CP (Cambridge 2; n = 9) based on magnetic resonance cholangiopancreatography findings using the Cambridge classification as the reference standard. Unenhanced T1 maps were acquired using a three-dimensional dual flip-angle gradient-echo technique on the same 1.5 T scanner with the same imaging parameters.

RESULTS

There was no significant difference between the T1 relaxation times of Cambridge 0 and 1 group (p = 0.58). There was a significant difference (p = 0.0003) in the mean T1 relaxation times of the pancreas between the combined Cambridge 0 and 1 (mean = 639 msec, 95% CI: 617, 660) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692, 759). There was significant difference (p = 0.0009) in the mean T1 relaxation times of the pancreas between the Cambridge 0 (mean = 636 msec, 95% CI: 606, 666) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692,759) as well as between Cambridge 1 (mean = 643 msec, 95% CI: 608, 679) and Cambridge 2 groups (mean = 726 msec, 95% CI: 692,759) (p = 0.0017). Bland-Altman analysis showed measurements of one reader to be marginally higher than the other by 15.7 msec (2.4%, p = 0.04).

CONCLUSION

T1 mapping is a practical method capable of quantitatively reflecting morphologic changes even in the early stages of chronic pancreatitis, and demonstrates promise for future implementation in routine clinical imaging protocols.

ADVANCES IN KNOWLEDGE

T1 mapping can distinguish subtle parenchymal changes seen in early stage CP, and demonstrates promise for implementation in routine imaging protocols for the diagnosis of CP.

Acute-on-Chronic Pancreatitis: Analysis of Clinical Profile and Outcome

OBJECTIVE

Overall, a handful of studies are available on the outcomes of acute-on-chronic pancreatitis (ACP). We aimed to provide a more complete and updated picture of ACP.

METHODS

We evaluated consecutive patients of acute exacerbation of chronic pancreatitis (CP) in a tertiary care center located in north India and studied their epidemiological profiles, etiological factors as well as outcomes.

RESULTS

Forty-five patients of ACP with a mean age of 37±13 years were evaluated. The majority of the patients were male (75%) and alcohol was the most common detectable etiology while no etiology could be identified in 35% of patients after extensive laboratory investigations and imaging. Moderately severe pancreatitis was noted in 73% of patients and 49% of patients had necrotizing pancreatitis out of which the majority (33%) had both pancreatic as well as extra-pancreatic necrosis (EPN). Five patients (11%) were subjected to percutaneous catheter drainage. Persistent organ failure was noted in 9% of patients and two (4.5%) patients had died from organ failure.

CONCLUSION

To conclude, this study has demonstrated that ACP has a milder disease course and low morbidity and mortality. Early elimination of the etiological factor is essential for optimal outcome.

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.

Low serum trypsinogen levels in chronic pancreatitis: Correlation with parenchymal loss, exocrine pancreatic insufficiency, and diabetes but not CT-based cambridge severity scores for fibrosis

BACKGROUND

Chronic pancreatitis (CP) is a complex inflammatory disorder of the pancreas affecting acinar cells, duct cells, islet cells and inflammatory cells including fibrosis-producing stellate cells. Serum trypsinogen is a biomarkers of acinar cell function.

AIM

To define the degree of correlation between low trypsinogen levels as a marker of acinar cell function and variable features of CP.

METHODS

Serum samples from previously ascertained and well phenotyped case and control subjects from the North American Pancreatitis Study II (NAPS2) were used to measure serum trypsinogen levels in a commercial laboratory. Control samples were used to define normal ranges and compared with levels in CP patients with defined features.

RESULTS

A final cohort of 279 CP patients and 262 controls from the NAPS2 studies were evaluated. In controls trypsinogen had a mean of 34.96 ng/ml and SD = 11.99. Cut-off values for low trypsinogen ranged from <20 to 10 ng/ml and very low trypsinogen at <10 ng/ml. Compared to controls, CP was associated with very low trypsinogen levels (p < 0.0001). Within CP, very low trypsinogen levels correlated with parenchymal loss (pancreatic surgery [p < 0.05]; atrophy with calcifications, [p < 0.001]), EPI (p < 0.01, trend p < 0.001) and diabetes (trend p < 0.01) but not CT-based criteria for fibrosis (pancreatic duct dilation, irregularity, strictures).

CONCLUSIONS

Very low serum trypsinogen levels correlate with measures of acinar cell loss including surgical resection, atrophic-calcific CP, diabetes and functional symptoms EPI but not duct morphology criteria. Serum trypsinogen levels correlate with decreased acinar cell function and therefore have biomarker utility clinical management.

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.

The diagnostic value of Rosemont and Japanese diagnostic criteria for 'indeterminate', 'suggestive', 'possible' and 'early' chronic pancreatitis

BACKGROUND

Longitudinal data are lacking to support consensus criteria for diagnosing early chronic pancreatitis.

METHODS

Retrospective single centre study of the initial evidence for chronic pancreatitis (CP), with reassessment after follow-up (January 2003-November 2016).

RESULTS

807 patients were previously diagnosed with chronic pancreatitis. This diagnosis was rejected in 118 patients: 52 had another pathology altogether, the remaining 66 patients formed the study population. 38 patients with 'normal' imaging were reclassified as chronic abdominal pain syndrome (CAPS), and 28 patients had minimal change features of CP on EUS (MCEUS) but never progressed. Strict application of the Japanese diagnostic criteria would diagnose only two patients with early CP and eleven as possible CP. Patients were more likely to have MCEUS if the EUS was performed within 12 months of an attack of acute pancreatitis. 40 patients with MCEUS were identified, including an additional 12 who progressed to definite CP after a median of 30 (18.75-36.5) months. Those continuing to consume excess alcohol and/or continued smoking were significantly more likely to progress. Those who progressed were more likely to develop pancreatic exocrine insufficiency, require pancreatic surgery and had higher mortality.

CONCLUSION

There needs to be more stringent application of the systems used for diagnosing chronic pancreatitis with revision of the current terminology 'indeterminate', 'suggestive', 'possible', and 'early' chronic pancreatitis. All patients with MCEUS features of CP require ongoing clinical follow up of at least 30 months and all patients with these features should be strongly counselled regarding smoking cessation and abstinence from alcohol.

Quantitative MR Evaluation of Chronic Pancreatitis: Extracellular Volume Fraction and MR Relaxometry

OBJECTIVE

The purpose of this study was to determine if extracellular volume fraction and T1 mapping can be used to diagnose chronic pancreatitis (CP).

MATERIALS AND METHODS

This HIPAA-compliant study analyzed 143 consecutive patients with and without CP who underwent MR imaging between May 2016 and February 2017. Patients were selected for the study according to inclusion and exclusion criteria that considered history and clinical and laboratory findings. Eligible patients (n = 119) were grouped as normal (n = 60) or with mild (n = 22), moderate (n = 27), or severe (n = 10) CP on the basis of MRCP findings using the Cambridge classification as the reference standard. T1 maps were acquired in unenhanced and late contrast-enhanced phases using a 3D dual flip-angle gradient-echo sequence. All patients were imaged on the same 3-T scanner using the same imaging parameters, contrast agent, and dosage.

RESULTS

Mean extracellular volume fractions and T1 relaxation times were significantly different within the study groups (one-way ANOVA, p < 0.001). Using the AUC curve analysis, extracellular volume fraction of > 0.27 showed 92% sensitivity (54/59) and 77% specificity (46/60) for the diagnosis of CP (AUC = 0.90). A T1 relaxation time of > 950 ms revealed 64% sensitivity (38/59) and 88% specificity (53/60) (AUC = 0.80). Combining extracellular volume fraction and T1 mapping yielded sensitivity of 85% (50/59) and specificity of 92% (55/60) (AUC = 0.94).

CONCLUSION

Extracellular volume fraction and T1 mapping may provide quantitative metrics for determining the presence and severity of acinar cell loss and aid in the diagnosis of CP.

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

PURPOSE

To determine if T1-weighted MR signal of the pancreas can be used to detect early CP.

METHODS

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.

RESULTS

There was a significant difference in the signal intensity ratio of the pancreas to spleen (SIR_p/s) between the normal and low bicarbonate groups (p < 0.0001). A significant positive correlation was found between pancreatic fluid bicarbonate level and SIR_p/s (p < 0.0001). SIR_p/s of 1.2 yielded sensitivity of 77% and specificity of 83% for detection of pancreatic exocrine dysfunction (AUC: 0.89).

CONCLUSION

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.

Surgical approaches to chronic pancreatitis: indications and imaging findings

Chronic pancreatitis (CP) is an irreversible, inflammatory process characterized by progressive fibrosis of the pancreas that can result in abdominal pain, exocrine insufficiency, and diabetes. Inadequate pain relief using medical and/or endoscopic therapies is an indication for surgery. The surgical management of CP is centered around three main operations including pancreaticoduodenectomy (PD), duodenum-preserving pancreatic head resection (DPPHR) and drainage procedures, and total pancreatectomy with islet autotransplantation (TPIAT). PD is the method of choice when there is a high suspicion for malignancy. Combined drainage and resection procedures are associated with pain relief, higher quality of life, and superior short-term and long-term survival in comparison with the PD. TPIAT is a reemerging treatment that may be promising in subjects with intractable pain and impaired quality of life. Imaging examinations have an extensive role in pre-operative and post-operative evaluation of CP patients. Pre-operative advanced imaging examinations including CT and MRI can detect hallmarks of CP such as calcifications, pancreatic duct dilatation, chronic pseudocysts, focal pancreatic enlargement, and biliary ductal dilatation. Post-operative findings may include periportal hepatic edema, pneumobilia, perivascular cuffing and mild pancreatic duct dilation. Imaging can also be useful in the detection of post-operative complications including obstructions, anastomotic leaks, and vascular lesions. Imaging helps identify unique post-operative findings associated with TPIAT and may aid in predicting viability and function of the transplanted islet cells. In this review, we explore surgical indications as well as pre-operative and post-operative imaging findings associated with surgical options that are typically performed for CP patients.

Chronic pancreatitis: An international draft consensus proposal for a new mechanistic definition

BACKGROUND

A definition of chronic pancreatitis (CP) is needed for diagnosis and distinguishing CP from other disorders. Previous definitions focused on morphology. Advances in epidemiology, genetics, molecular biology, modeling and other disciplines provide new insights into pathogenesis of CP, and allow CP to be better defined.

METHODS

Expert physician-scientists from the United States, India, Europe and Japan reviewed medical and scientific literature and clinical experiences. Competing views and approaches were debated until a new consensus definition was reached.

RESULTS

CP has been defined as 'a continuing inflammatory disease of the pancreas, characterized by irreversible morphological change, and typically causing pain and/or permanent loss of function'. Focusing on abnormal morphology makes early diagnosis challenging and excludes inflammation without fibrosis, atrophy, endocrine and exocrine dysfunction, pain syndromes and metaplasia. A new mechanistic definition is proposed--'Chronic pancreatitis is a pathologic fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress.' In addition, "Common features of established and advanced CP include pancreatic atrophy, fibrosis, pain syndromes, duct distortion and strictures, calcifications, pancreatic exocrine dysfunction, pancreatic endocrine dysfunction and dysplasia." This definition recognizes the complex nature of CP, separates risk factors from disease activity markers and disease endpoints, and allows for a rational approach to early diagnosis, classification and prognosis.

CONCLUSIONS

Initial agreement on a mechanistic definition of CP has been reached. This definition should be debated in rebuttals and endorsements, among experts and pancreatic societies until international consensus is reached.

Mechanism, assessment and management of pain in chronic pancreatitis: Recommendations of a multidisciplinary study group

DESCRIPTION

Pain in patients with chronic pancreatitis (CP) remains the primary clinical complaint and source of poor quality of life. However, clear guidance on evaluation and treatment is lacking.

METHODS

Pancreatic Pain working groups reviewed information on pain mechanisms, clinical pain assessment and pain treatment in CP. Levels of evidence were assigned using the Oxford system, and consensus was based on GRADE. A consensus meeting was held during PancreasFest 2012 with substantial post-meeting discussion, debate, and manuscript refinement.

RESULTS

Twelve discussion questions and proposed guidance statements were presented. Conference participates concluded: Disease Mechanism: Pain etiology is multifactorial, but data are lacking to effectively link symptoms with pathologic feature and molecular subtypes. Assessment of Pain: Pain should be assessed at each clinical visit, but evidence to support an optimal approach to assessing pain character, frequency and severity is lacking.

MANAGEMENT

There was general agreement on the roles for endoscopic and surgical therapies, but less agreement on optimal patient selection for medical, psychological, endoscopic, surgical and other therapies.

CONCLUSIONS

Progress is occurring in pain biology and treatment options, but pain in patients with CP remains a major problem that is inadequately understood, measured and managed. The growing body of information needs to be translated into more effective clinical care.

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.

Approach to patients with suspected chronic pancreatitis: a comprehensive review

Chronic pancreatitis (CP) represents a significant health care burden in the United States. Diagnosing it early and accurately is important for the efficient management of these patients. However, the early diagnosis of CP, when structural and functional pancreatic changes are subtle, remains difficult. Complicating this is the large cohort of patients with nonspecific abdominal pain who are often suspected of having early CP and who utilize significant health care resources in attempts at diagnosis and management. We present a review of the current diagnostic tests available for making an early diagnosis of CP. We further report our approach to patients suspected of having CP based on the available literature.

A population-based study of severity in patients with acute on chronic pancreatitis

OBJECTIVES

The objectives of this study were to evaluate the severity of patients with acute pancreatitis (AP) on chronic pancreatitis (CP) and compare this to patients with AP without CP.

METHODS

The Maryland Health Services database was queried for all adult inpatient discharges with a primary diagnosis of AP from 1994 to 2010. Acute pancreatitis on CP and AP without CP were defined by the presence of the associated diagnosis code for CP. Severity was defined as organ failure, intensive care unit stay, or mortality.

RESULTS

Acute pancreatitis on CP accounted for 13.7% of all AP discharges (9747/70,944). The proportion of AP-on-CP discharges doubled during the study period (8.8% to 17.6%; P < 0.0001). When compared with patients with AP without CP, AP-on-CP patients were younger, were more likely to be male and black, had higher rates of alcohol and drug abuse, and had less severe disease with lower rates of mortality, organ failure, need for mechanical ventilation, and intensive care unit stay. Among AP-on-CP patients, significant predictors of severity included advanced age, weight loss, and 2 or more comorbidities.

CONCLUSIONS

Patients with AP on CP have less severe disease than do those with AP without CP. Weight loss, advanced age, and comorbidity increase the risk of severity in patients with AP on CP.

Low prevalence of exocrine pancreatic insufficiency in patients with diabetes mellitus

INTRODUCTION

Exocrine pancreatic insufficiency (EPI) can occur in patients with diabetes mellitus (DM). Incidence of EPI and its clinical significance remain poorly defined. The aim of our study was to determine whether exocrine pancreatic function is impaired in patients with DM.

PATIENTS AND METHODS

One hundred and fifty consecutive patients, mean age 59.0 (± 12.0 years), with DM lasting at least 5 years were included in the study. We included 50 patients with type 1 DM (DM1), 50 insulin-treated patients DM type 2 (DM2-insulin) and 50 non-insulin treated patients with DM type 2 (DM2 no-insulin). Diagnosis of DM was established from health records, lasting 15.0 ± 9.9 years on average. EPI was diagnosed with a fecal elastase-1 concentration (FE1) of less than 200 μg/g (ELISA).

RESULTS

FE1 was reduced in 8 (5.4%) patients: mildly reduced (100-200 μg/g) in 4 patients (2.7%) and markedly reduced (<100 μg/g) in 4 patients (2.7%). Frequency of EPI was 3 in DM1, 5 in DM2(insulin) and none in DM2 (no-insulin) groups.

CONCLUSIONS

EPI in DM occurred less frequently than in previous studies, probably due to our strict exclusion criteria (age, alcohol intake).

Quantitative analysis of pancreatic exocrine function in healthy adults using secretin-enhanced MRCP

AIM: To assess the value of secretin-enhanced magnetic resonance cholangiopancreatography (MRCP) and fecal elastase 1 (FE-1) tests for quantification of exocrine function in normal adults.

METHODS: From April 2011 to January 2013, 17 healthy volunteers were enrolled in the study. There were 5 females and 12 males. Their median age was 44.0 years ± 14.4 years (24-64 years), and their median BMI was 24.5 ± 13.4 (18.9-31.1). All subjects had undergone both MRCP and FE-1. Coronal T2-weighted sequences and MRCP were performed before and at a 2 min interval after administration of 0.1 mL/kg secretin. Semiquantitative s-MRCP grading for duodenal filling was used to preliminarily assess the exocrine function of the pancreas. By drawing an appropriate region of interest, changes in signal intensity in the imaging volume were plotted against time and the flow rate derived from the gradient. Pancreatic exocrine secretions were quantified by pancreatic flow output (PFR) and peak time (PT).

RESULTS: Phantom experiments showed a good correlation between known and calculated volumes of water (P < 0.001). Ten minutes after secretin administration, 17 volunteers showed a duodenal filling beyond the genu inferius (grade 3). Mean FE-1 was 353.3 μg/g ± 134.7 μg/g (range 201.55 μg/g-673.20 μg/g). Mean PFR was 8.17 mL/min ± 1.11 mL/min (range 6.2 mL/min-11 mL/min), and mean PT was 5.2 min ± 1.2 min (range 3-7 min). There is a good correlation between PFR and FE-1 (P < 0.001).

CONCLUSION: Semi-SMRCPQ can be used to preliminarily assess the exocrine function of the pancreas. SMRCP provides a safe, non-invasive, efficient method for evaluating the exocrine function of the pancreas.

Pancreatic duct changes are not associated with early signs of chronic pancreatitis at magnetic resonance imaging (MRI) in patients with primary sclerosing cholangitis

OBJECTIVE

The association between chronic pancreatitis (CP) and primary sclerosing cholangitis (PSC) has been reported previously. The aims of the present study were to evaluate the presence of early pancreatic abnormalities and duct changes, using MRCP/MRI in PSC and to evaluate possible risk factors for these changes and their clinical importance.

MATERIALS AND METHODS

One hundred and three patients with PSC were identified among all MRI liver/pancreas referrals in 2001-2005. MRCP was used to grade pancreatic duct changes in three groups: grade 0 (normal), grade 1 (mild) and grade 2 (severe). For detection of early MRI signs of CP, the pancreas-spleen signal intensity ratio (SIR), the arterial and early venous phase ratio (A/PV ratio) and the age-related size of the pancreas were evaluated.

RESULTS

Pancreatic duct changes were found in 24% of the PSC patients. The pancreatic duct changes were associated with extrahepatic biliary involvement and long duration of PSC but not associated with pancreas-spleen SIR, A/PV ratio, pancreas size, previous post-ERCP or acute pancreatitis. Severe pancreatic duct changes were significantly associated to abdominal pain. Clinically significant CP was seen in one PSC patient (1%).

CONCLUSIONS

Pancreatic duct changes are associated with extrahepatic bile duct strictures and not with the early MRI signs of CP. Therefore, pancreatic duct changes seem to be part of the spectrum of PSC and should not be defined as CP. Pancreatic duct changes are of limited clinical importance but may contribute to abdominal pain in PSC.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

Despite discrepancies between pancreatic exocrine function and the findings on standard MRI/MRCP, the S-MRCP findings are comparable to ePFT in the evaluation of chronic pancreatitis.

Advanced imaging of chronic pancreatitis

Chronic pancreatitis is characterized by continuing inflammation, destruction, and irreversible morphological changes in the pancreatic parenchyma and ductal anatomy. These changes lead to chronic pain and/or loss of function. Although these definitions are simple, the clinical diagnosis of chronic pancreatitis remains difficult to make, especially for early disease. Routine imaging modalities such as transabdominal ultrasound and standard CT scans are insensitive for depicting early disease, and detect only advanced chronic pancreatitis. Advances in imaging modalities including CT, MRI with gadolinium contrast enhancement, MRI with magnetic resonance cholangiopancreatography (MRI/MRCP), MRI/MRCP with secretin-stimulation (S-MRCP), endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasound (EUS) allow earlier diagnosis of chronic pancreatitis. This article reviews the recognized findings, advantages, and disadvantages of the various imaging modalities in the management of chronic pancreatitis, specifically CT, MRI with or without MRCP and/or S-MRCP, ERCP, and EUS.

Chronic pancreatitis

PURPOSE OF REVIEW

We review important new clinical observations in chronic pancreatitis made in the last year.

RECENT FINDINGS

Cholecystokinin-stimulated endoscopic pancreatic function testing has low specificity for diagnosis of early chronic pancreatitis, likely because of correctable technical limitations or failure to exclude confounding diseases. Fecal elastase 1 is a poor test for diagnosing pancreatic malabsorption. A 2-week trial of corticosteroids may differentiate autoimmune pancreatitis (AIP) from pancreatic cancer in select patients. A genetic screen may help to predict relapse of AIP. Repeated, 6-month visits to counsel against alcohol use may reduce recurrent attacks of alcoholic pancreatitis. A five-component antioxidant cocktail may reduce the frequency of pain in chronic pancreatitis by 1.5 days per month.

SUMMARY

Researchers this last year have further characterized clinical aspects of chronic pancreatitis that may lead to improved detection of early chronic pancreatitis and AIP, risk stratification and application of risk-lowering strategies to prevent relapses in AIP or the development of recurrent (and possibly chronic) alcoholic pancreatitis and new evidence that antioxidants may have a modest effect on reducing the dominant symptom in chronic pancreatitis, abdominal pain.

Magnetic resonance cholangiopancreatography for the detection of pancreatic duct stones in patients with chronic pancreatitis

AIM: To assess the role of magnetic resonance cholangiopancreatography (MRCP) in detection of pancreatic duct stones (PDS) in patients with chronic pancreatitis (CP).

METHODS: Clinical data of 78 CP patients who were treated at the First Affiliated Hospital of Xi’an Jiaotong University (China) between January 2004 and July 2008 were retrospectively analyzed. A predictive model of pancreatic duct stones was established through logistic regression and its effectiveness was verified. Among these patients, MRCP was performed in 60 patients who served as a control group, while 44 patients with a higher predictive value than the entry threshold of the predictive model served as an experimental group.

RESULTS: The positive rate of PDS in the 78 patients with CP was 19.2% (15/78). The predictive entry threshold of the predictive model was 5% (P < 0.05). The possibility of existence of PDS could be predicted according to the following 4 indexes: gastrointestinal symptoms, intermittent abdominal pain, diabetes mellitus (DM)/impaired glucose tolerance (IGT) and positive B-mode ultrasound results. The incidence of PDS in the experimental group was higher than that in the control group (P < 0.05).

CONCLUSION: MRCP is strongly suggested for the detection of PDS in patients with gastrointestinal symptoms, intermittent abdominal pain, DM/IGT and positive B-mode ultrasound results.

Magnetic resonance imaging in pancreatitis

Pancreatitis can occur in acute and chronic forms. Magnetic resonance imaging (MRI) plays an important role in the early diagnosis of both conditions and complications that may arise from acute or chronic inflammation of the gland. Standard MRI techniques including T1-weighted and T2-weighted fat-suppressed imaging sequences together with contrast-enhanced imaging can both aid in the diagnosis of acute pancreatitis and demonstrate complications as pseudocysts, hemorrhage, and necrosis. Combined use of MRI and MR cholangiopancreatography can show both parenchymal findings that are associated with chronic pancreatitis including pancreatic size and signal and arterial enhancements, all of which are diminished in chronic pancreatitis. The degree of main pancreatic duct dilatation and/or the number of side branch ectasia determines the diagnosis of chronic pancreatitis and its severity. In this paper, we report the spectrum of imaging findings of acute and chronic pancreatitis on MRI and MR cholangiopancreatography.