Imaging of chronic pancreatitis

Chronic Pancreatitis: Epidemiology, Diagnosis, and Management Updates

Chronic pancreatitis is a clinical entity that results from the progressive inflammation and irreversible fibrosis of the pancreas resulting from the cumulative injury sustained by the pancreas over time. It is an illness with variable presentations that can severely impact quality of life, while its long-term complications such as exocrine pancreatic insufficiency (EPI), diabetes mellitus, and risk of pancreatic cancer can become life threatening. The diagnosis of chronic pancreatitis can be challenging as despite the recent advancements in imaging technology, the radiographic findings do not become prominent until late stages of disease. Thus, the physicians' clinical acumen in obtaining thorough history taking focusing on risk factors, clinical symptoms, in addition to high-quality imaging, often guide to the accurate diagnosis of chronic pancreatitis. Endoscopy also plays a pivotal role in the diagnosis and management of chronic pancreatitis. Endoscopic ultrasound (EUS) is believed to be the most sensitive modality for diagnosing chronic pancreatitis. Despite efforts, however, natural history studies have demonstrated that 61% of individuals with chronic pancreatitis will require at least one endoscopic intervention, while 31% will require a surgical procedure as part of their management strategy. Recent advancements in genomic studies have furthered our understanding of the genetic polymorphisms that are associated with the pathogenesis of chronic pancreatitis. Genetic testing offers the potential to reveal treatable pancreatitis-related disorders, and can inform decision making with regard to radical therapies for persistent or severe disease such as total pancreatectomy with islet autotransplantation (TPIAT). The management of patients suffering from chronic pancreatitis often requires a multi-disciplinary approach, addressing pertinent symptoms as well as the sequelae of chronic inflammation and fibrosis. Abdominal pain is the prevailing symptom and most common complication of chronic pancreatitis, and impairs quality of life. Although heavily dependent on a wide range of analgesia, endoscopic treatment such as endoscopic retrograde cholangiopancreatography (ERCP) and surgical intervention can offer long-lasting relief of symptoms. For EPI, treatment with pancreatic enzyme supplements offers marginal-to-moderate relief. The most feared complication of chronic pancreatitis-the development of pancreatic cancer-has no known prevention measure to date.

Current advances in the management of chronic pancreatitis

Chronic pancreatitis is characterized by irreversible destruction of pancreatic parenchyma and its ductal system resulting from longstanding inflammation, leading to fibrosis and scarring due to genetic, environmental, and other risk factors. The diagnosis of chronic pancreatitis is made based on a combination of clinical features and characteristic findings on computed tomography or magnetic resonance imaging. Abdominal pain is the most common symptom of chronic pancreatitis. The main aim of treatment is to relieve symptoms, prevent disease progression, and manage complications related to chronic pancreatitis. Patients who do not respond to medical treatment or not a candidate for surgical treatment are usually managed with endoscopic therapies. Endoscopic therapies help with symptoms such as abdominal pain and jaundice by decompression of pancreatic and biliary ducts. This review summarizes the risk factors, pathophysiology, diagnostic evaluation, endoscopic treatment of chronic pancreatitis, and complications. We have also reviewed recent advances in endoscopic retrograde cholangiopancreatography and endoscopic ultrasound-guided therapies for pancreatic duct obstruction due to stones, strictures, pancreatic divisum, and biliary strictures.

[Imaging in the acute abdomen - part 1 : Case examples of frequent organ-specific causes: liver, gallbladder, pancreas, spleen and vessels]

The acute abdomen is characterized by acute abdominal pain with defensive muscular tension, can be triggered by a variety of diseases and sometimes represents a life-threatening condition. After clinical inspection, in most cases dedicated imaging should be performed immediately. The frequently causal appendicitis and cholecystitis can mostly be diagnosed with ultrasound. In other cases with unclear ultrasound findings or unclear severe symptoms, computer tomography (CT) is usually necessary without delay. In contrast, magnetic resonance imaging (MRI) is predominantly indicated in pregnant women and children with unclear ultrasound findings. Thus, the radiologist is an important gatekeeper in the diagnostics of acute abdomen. The radiologist should therefore be familiar with the correct imaging indications, the frequent and rare causes as well as the corresponding morphological imaging characteristics.

Validation of threshold values for pancreas thickness and T1-weighted signal intensity ratio in the pediatric pancreas

BACKGROUND

Pancreas atrophy and the loss of T1-weighted signal intensity by magnetic resonance imaging (MRI) are findings of chronic pancreatitis.

OBJECTIVE

The purpose of this study was to test published normal values and cutoffs for pancreas thickness and the pancreas:spleen T1-weighted signal intensity ratio in children without pancreatic disease.

MATERIALS AND METHODS

This was a secondary analysis of prospectively collected MRI data for 50 children (range: 6.3-15.9 years; 27 female) with no history of pancreatic disease. Two observers (R1, R2) measured linear pancreas thickness on axial T1-weighted, fat-saturated gradient recalled echo images and placed regions of interest in the pancreas and spleen to calculate the T1-weighted signal intensity ratio. Measurements were compared to published pediatric normal values (computed tomography [CT], ultrasound [US]) and adult cutoffs (CT, MRI).

RESULTS

Compared to published pediatric values for CT, 68% (R1: 34/50) or 40% (R2: 22/50) of participants had ≥1 pancreas segment with thickness below the normal range. No participant had a thickness value below the normal range published for US. Compared to cutoff values in adults, 84% (R1: 42/50) or 80% (R2: 40/50) of participants met the criteria for pancreas atrophy. Mean T1-weighted signal intensity ratio was 1.33±0.15 (R1) and 1.32±0.16 (R2). Twelve (R1: 24.5% of 49) or 11/49 (R2: 22.4%) participants had a T1-weighted signal intensity ratio below the threshold associated with exocrine insufficiency in adults.

CONCLUSION

Previously defined thresholds for pancreas thickness and pancreas:spleen T1-weighted signal intensity ratio appear too restrictive for a pediatric population. Further study is needed to define optimal quantitative metrics for findings of chronic pancreatitis in children.

Significance of pancreatic calcification on preoperative computed tomography of intraductal papillary mucinous neoplasms

BACKGROUND AND AIM

Chronic pancreatitis is a risk factor for pancreatic cancer. Pancreatic calcification is a characteristic of chronic pancreatitis; however, its significance for intraductal papillary mucinous neoplasm (IPMN) oncogenesis remains unknown. Therefore, we investigated the relationship between pancreatic calcification and invasive IPMN.

METHODS

This study included 157 patients who underwent resection for IPMN between April 2001 and October 2016 (intraductal papillary mucinous adenoma, n = 76; noninvasive intraductal papillary mucinous carcinoma [IPMC], n = 32; and invasive IPMC, n = 49). We divided the subjects on the basis of the presence/absence of pancreatic calcification on preoperative computed tomography (CT). The factors associated with pancreatic calcification were investigated in univariate analyses. Then, multivariate logistic regression analyses of the relationship between pancreatic calcification and invasive IPMC (after adjusting for clinical or imaging characteristics) were conducted.

RESULTS

Preoperative CT revealed pancreatic calcification in 17.2% (27/157) of the resected IPMN. In the univariate analyses, jaundice, high serum carbohydrate antigen 19-9 levels, and invasive IPMC were significantly associated with pancreatic calcification (4/27 [14.8%] vs 4/130 [3.1%], 0.01; 12/27 [44.4%] vs 31/130 [23.8%], 0.03; and 15/27 [55.6%] vs 34/130 [26.2%], 0.001, respectively). Pancreatic calcification was significantly associated with invasive IPMC (multivariate odds ratio = 2.88, 95% confidence interval [95% CI] = 1.15-7.21, 0.03, adjusted for clinical characteristics; odds ratio = 5.50, 95% CI = 1.98-15.3, 0.001, adjusted for imaging characteristics).

CONCLUSIONS

Pancreatic calcification on CT is associated with invasive IPMC. Pancreatic calcification might be a predictor of invasive IPMC.

Pancreatic Ultrasound: State of the Art

An ultrasound (US) study is often the first imaging approach in patients with abdominal symptoms or signs related to abdominal diseases, and it is often part of the routine workup. The pancreatic gland, despite its retroperitoneal site, can be efficiently examined with US thanks to advances in US technologies. Nowadays, a pancreatic US study could be considered complete if multiparametric, including the use of Doppler imaging, US elastography, and contrast-enhanced imaging for the study of a pancreatic mass. A complete US examination could contribute to a faster diagnosis, especially if the pancreatic lesion is incidentally detected, addressing second-step imaging modalities correctly.

Imaging in chronic pancreatitis: State of the art review

Chronic pancreatitis (CP) is an important gastrointestinal cause of morbidity worldwide. It can severely impair the quality of life besides life-threatening acute and long-term complications. Pain and pancreatic exocrine insufficiency (leading to malnutrition) impact the quality of life. Acute complications include pseudocysts, pancreatic ascites, and vascular complications. Long-term complications are diabetes mellitus and pancreatic cancer. Early diagnosis of CP is crucial to alter the natural course of the disease. However, majority of the cases are diagnosed in the advanced stage. The role of various imaging techniques in the diagnosis of CP is discussed in this review.

Normal pancreatic parenchymal thickness by CT in healthy children

BACKGROUND

Chronic pancreatitis is increasingly recognized in the pediatric population. Atrophy is an important, but qualitative, finding of chronic pancreatitis. To transition to a quantitative measure that can specifically define atrophy requires knowledge of normal pancreatic parenchymal bulk in children.

OBJECTIVE

The purpose of this study was to define normal pancreatic thickness (linear measurements) at multiple anatomic locations in the pancreas of healthy children.

MATERIALS AND METHODS

This was an Institutional Review Board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. Three reviewers measured the thickness of the pancreas at four locations (head, neck, body, tail) on computed tomography (CT) examinations performed with intravenous contrast in children without a history of pancreatic disease. Measurements were made on 140 examinations, evenly distributed among 7 age groups (3-16.99 years) with 10 males and 10 females in each group. Agreement and bias between reviewers were assessed by intra-class correlation coefficients (ICC) and Bland-Altman analyses. Correlation with age, height and weight were assessed with Spearman's rho (ρ).

RESULTS

The mean (for 3 readers) thicknesses of the head, neck, body and tail were 1.3-2 cm, 0.7-1 cm, 0.9-1.6 cm and 1-1.6 cm, respectively, depending on patient age. Measurement agreement between reviewers was fair to good (ICC: 0.52-0.7). Bias between reviewers ranged from 0 to 3 mm. Pancreatic thickness was weakly to moderately correlated with age (ρ=0.39-0.52), height (ρ=0.44-0.61) and weight (ρ=0.51-0.64).

CONCLUSION

We have defined normal ranges for thickness of the pancreas at four locations, and have shown that these measurements depend on patient age and size. These data may be useful to more objectively define pancreatic atrophy in children with suspected pancreatic disease.

Gadolinium-based relative contrast enhancement in primary sclerosing cholangitis: additional benefit for clinicians?

AIM

To evaluate the benefit of extracellular gadolinium-based contrast agent (GBCA) enhanced magnetic resonance imaging (MRI) in addition to conventional non-enhanced T2-weighted imaging (WI) for quantification of inflammatory or fibrotic alterations in the liver parenchyma of patients with primary sclerosing cholangitis (PSC).

MATERIAL AND METHODS

MRI (3 T) examinations were reviewed retrospectively by two radiologists in 27 PSC patients (age 42.9±15.6 years), and 19 controls. Regions of interest (ROIs) were drawn onto T2 hyperintense and T2 isointense areas and copied to section position matched non-enhanced and delayed-phase contrast-enhanced T1WI. Signal intensities (SI) obtained from ROIs of the multiphase T1WI were used to calculate relative liver enhancement (RLE). The interobserver agreement of RLE and quantified T2 signal was calculated using Bland-Altman analysis. RLE assessed for both T2 hyperintense (RLE_hyper) and T2 isointense (RLE_iso) areas were compared in patients and controls (RLE_healthy).

RESULTS

The interobserver agreement of RLE in affected hyperintense areas (bias -0.77, limits of agreement -51.7 to 50.1) was superior to the quantification of T2 signal only in these areas (bias -3.35, limits of agreement -162.4 to 155.7). The RLE_hyper (86.2±9.7%) was higher than the RLE_iso (59.8±6.2%, p=0.03) and the RLE_healthy (53.2±2.7%, p=0.002). The mean RLE_iso was not significantly different from the RLE_healthy (p=0.3).

CONCLUSION

The extracellular gadolinium-based RLE of T2 hyperintense areas could be a useful add-on for routine follow up MRI in the detection of early inflammatory changes, possibly preceding formation of fibrotic scarring in PSC patients, if validated in larger cohorts.

Clinical Value of Contrast-Enhanced Ultrasound Enhancement Patterns for Differentiating Focal Pancreatitis From Pancreatic Carcinoma: A Comparison Study With Conventional Ultrasound

OBJECTIVES

We explored the clinical value of using contrast-enhanced ultrasound (US) enhancement patterns for the differential diagnosis of focal pancreatitis from pancreatic carcinoma.

METHODS

A total of 136 solid pancreatic lesions with final diagnoses from January 2010 to February 2016 were enrolled in this study. Twenty-five cases were focal pancreatitis; 86 cases were pancreatic carcinoma; and 25 cases were other types. All of the patients received conventional and contrast-enhanced US examinations. Two experienced US physicians analyzed the contrast-enhanced US enhancement patterns and made diagnoses according to the conventional and contrast-enhanced US manifestations. The inter-rater agreement for the contrast enhancement patterns between the readers was analyzed. The diagnostic efficiency of contrast enhancement patterns for differentiating focal pancreatitis from pancreatic carcinoma was analyzed and compared with that of conventional US.

RESULTS

The κ test showed good concordance for contrast enhancement patterns between the readers (P < .05). The diagnostic sensitivity, specificity, and accuracy of isoenhancement or isoenhancement with focal hypoenhancement in both the early and late phases for diagnosing focal pancreatitis were 72.0%, 95.5%, and 91.2%, respectively. The diagnostic sensitivity of isoenhancement or isoenhancement with focal hypoenhancement in both the early and late phases greatly increased for diagnosing focal pancreatitis in comparison with isoenhancement (72.0% versus 32.0%; P < .05). The diagnostic accuracy of contrast-enhanced US was greatly increased over that of conventional US (85.6% versus 49.5%; P < .001).

CONCLUSIONS

Contrast-enhanced US is a valuable tool for differentiating focal pancreatitis from pancreatic carcinoma and can greatly increase the diagnostic accuracy over conventional US.

Association between Smoking and the Progression of Computed Tomography Findings in Chronic Pancreatitis

Background/Aims

Smoking and alcohol intake are two well-known risk factors for chronic pancreatitis. However, there are few studies examining the association between smoking and changes in computed tomography (CT) findings in chronic pancreatitis. The authors evaluated associations between smoking, drinking and the progression of calcification on CT in chronic pancreatitis.

Methods

In this retrospective study, 59 patients with chronic pancreatitis who had undergone initial and follow-up CT between January 2002 and September 2010 were included. Progression of calcification among CT findings was compared according to the amount of alcohol intake and smoking.

Results

The median duration of follow-up was 51.6 months (range, 17.1 to 112.7 months). At initial CT findings, there was pancreatic calcification in 35 patients (59.3%). In the follow-up CT, progression of calcification was observed in 37 patients (62.7%). Progression of calcification was more common in smokers according to the multivariate analysis (odds ratio [OR], 9.987; p=0.006). The amount of smoking was a significant predictor for progression of calcification in the multivariate analysis (OR, 6.051 in less than 1 pack per day smokers; OR, 36.562 in more than 1 pack per day smokers; p=0.008).

Conclusions

Continued smoking accelerates pancreatic calcification, and the amount of smoking is associated with the progression of calcification in chronic pancreatitis.

Beyond the Bowel: Extraintestinal Manifestations of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic, relapsing immune-mediated inflammation of the gastrointestinal tract. IBD includes two major disease entities: Crohn disease and ulcerative colitis. Imaging plays an important role in the diagnosis and surveillance of these complex disorders. Computed tomographic and magnetic resonance enterographic techniques have been refined in recent years to provide a superb means of evaluating the gastrointestinal tract for suspected IBD. Although the intestinal imaging manifestations of IBD have been extensively discussed in the radiology literature, extraintestinal imaging manifestations of IBD have received less attention. Multiple extraintestinal manifestations may be seen in IBD, including those of gastrointestinal (hepatobiliary and pancreatic), genitourinary, musculoskeletal, pulmonary, cardiac, ocular, and dermatologic disorders. Although many associations between IBD and extraintestinal organ systems have been well established, other associations have not been fully elucidated. Some extraintestinal disorders may share a common pathogenesis with IBD. Other extraintestinal disorders may occur as a result of unintended treatment-related complications of IBD. Although extraintestinal disorders within the abdomen and pelvis may be well depicted with cross-sectional enterography, other musculoskeletal and thoracic disorders may be less evident with such examinations and may warrant further investigation with additional imaging examinations or may be readily apparent from the findings at physical examination. Radiologists involved in the interpretation of IBD imaging examinations must be aware of potential extraintestinal manifestations, to provide referring clinicians with an accurate and comprehensive profile of patients with these complex disorders. ^© RSNA, 2017.

Diagnostic performance of imaging modalities in chronic pancreatitis: a systematic review and meta-analysis

OBJECTIVES

Obtain summary estimates of sensitivity and specificity for imaging modalities for chronic pancreatitis (CP) assessment.

METHODS

A systematic search was performed in Cochrane Library, MEDLINE, Embase and CINAHL databases for studies evaluating imaging modalities for the diagnosis of CP up to September 2016. A bivariate random-effects modeling was used to obtain summary estimates of sensitivity and specificity.

RESULTS

We included 43 studies evaluating 3460 patients. Sensitivity of endoscopic retrograde cholangiopancreatography (ERCP) (82%; 95%CI: 76%-87%) was significant higher than that of abdominal ultrasonography (US) (67%; 95%CI: 53%-78%; P=0.018). The sensitivity estimates of endoscopic ultrasonography (EUS), magnetic resonance imaging (MRI), and computed tomography (CT) were 81% (95%CI: 70%-89%), 78% (95%CI: 69%-85%), and 75% (95%CI: 66%-83%), respectively, and did not differ significantly from each other. Estimates of specificity were comparable for EUS (90%; 95%CI: 82%-95%), ERCP (94%; 95%CI: 87%-98%), CT (91%; 95% CI: 81%-96%), MRI (96%; 95%CI: 90%-98%), and US (98%; 95%CI: 89%-100%).

CONCLUSIONS

EUS, ERCP, MRI and CT all have comparable high diagnostic accuracy in the initial diagnosis of CP. EUS and ERCP are outperformers and US has the lowest accuracy. The choice of imaging modality can therefore be made based on invasiveness, local availability, experience and costs.

KEY POINTS

• EUS, ERCP, MRI and CT have high diagnostic sensitivity for chronic pancreatitis • Diagnostic specificity is comparable for all imaging modalities • EUS and ERCP are outperformers and US has the lowest accuracy • The choice of imaging can be made based on clinical considerations.

Diagnostic Imaging of the Hepatobiliary System: An Update

Recent advances in diagnostic imaging of the hepatobiliary system include MRI, computed tomography (CT), contrast-enhanced ultrasound, and ultrasound elastography. With the advent of multislice CT scanners, sedated examinations in veterinary patients are feasible, increasing the utility of this imaging modality. CT and MRI provide additional information for dogs and cats with hepatobiliary diseases due to lack of superimposition of structures, operator dependence, and through intravenous contrast administration. Advanced ultrasound methods can offer complementary information to standard ultrasound imaging. These newer imaging modalities assist clinicians by aiding diagnosis, prognostication, and surgical planning.

Computed Tomography and MRI of the Hepatobiliary System and Pancreas

MRI and computed tomographic (CT) imaging are becoming more common in the diagnosis of hepatobiliary and pancreatic disorders in small animals. With the advent of multislice CT scanners, sedated examinations in veterinary patients are feasible increasing the use of this imaging modality. CT and MRI provide additional information for dogs and cats with hepatobiliary and pancreatic diseases because of lack of superimposition of structures, operator dependence, and through intravenous contrast administration. This added value provides more information for diagnosis, prognosis, and surgical planning.

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.

Computed tomographic angiography under sedation in the diagnosis of suspected canine pancreatitis: a pilot study

Background

Computed tomography (CT) is highly accurate for diagnosing pancreatitis in humans. The diagnosis of pancreatitis in dogs is based on clinical signs, laboratory findings, and ultrasonographic (US) changes. There are, however, inherent limitations in relying on laboratory and ultrasound findings for the clinical diagnosis of pancreatitis in dogs.

Hypothesis/Objectives

We hypothesized that CT angiography would be a rapid and reliable method to confirm pancreatitis in dogs compared to ultrasonography. The aim was to describe the CT characteristics and compare them to ultrasound findings and correlate the CT appearance to the severity of the patients' clinical course.

Animals

A prospective pilot case series; 10 dogs with pancreatitis were enrolled if the history, clinical signs, laboratory, and ultrasonographic findings were indicative of pancreatitis.

Methods

A 3‐phase angiographic CT was performed under sedation. Afterward, each dog had US‐guided aspirates of the pancreas collected and blood drawn for cPLi assay. Images were evaluated for portion of visible pancreas, pancreatic size and margin, pancreatic parenchyma, presence of peripancreatic changes and contrast enhancement pattern. The results were compared with outcome.

Results

An enlarged, homogeneously to heterogeneously attenuating and contrast‐enhancing pancreas with ill‐defined borders was identified in all dogs. CT identified more features characterizing pancreatic abnormalities compared to US. Thrombi were found in 3/10 dogs. Three dogs with heterogeneous contrast enhancement had an overall poorer outcome than those with homogenous enhancement.

Conclusions and Clinical Importance

CT angiography under sedation was used in dogs to confirm clinically suspected pancreatitis and identified clinically relevant and potentially prognostic features of pancreatitis in dogs.

Current options for the diagnosis of chronic pancreatitis

The diagnostic options for chronic pancreatitis have evolved over recent years. The previous gold standard references for structural imaging and exocrine pancreatic function testing have both been supplanted and redesigned. Endoscopic retrograde pancreatography has now been overtaken by endoscopic ultrasound and magnetic resonance cholangiopancreatography, whilst the old technique for Dreiling tube pancreatic function testing has now been replaced by the endoscopic pancreatic function test. New advances in endoscopic ultrasound elastography have also extended the options for evaluating pancreatic masses to differentiate mass-forming chronic pancreatitis from malignancy. Genetic contribution to chronic pancreatitis is also now more widely recognized than ever before.

Ultrasonography in diagnosing chronic pancreatitis: New aspects

The course and outcome is poor for most patients with pancreatic diseases. Advances in pancreatic imaging are important in the detection of pancreatic diseases at early stages. Ultrasonography as a diagnostic tool has made, virtually speaking a technical revolution in medical imaging in the new millennium. It has not only become the preferred method for first line imaging, but also, increasingly to clarify the interpretation of other imaging modalities to obtain efficient clinical decision. We review ultrasonography modalities, focusing on advanced pancreatic imaging and its potential to substantially improve diagnosis of pancreatic diseases at earlier stages. In the first section, we describe scanning techniques and examination protocols. Their consequences for image quality and the ability to obtain complete and detailed visualization of the pancreas are discussed. In the second section we outline ultrasonographic characteristics of pancreatic diseases with emphasis on chronic pancreatitis. Finally, new developments in ultrasonography of the pancreas such as contrast enhanced ultrasound and elastography are enlightened.

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.

Bull's-eye pattern of pancreatic-duct stones on multidetector computed tomography and gene-mutation-associated pancreatitis (GMAP)

PURPOSE

This study prospectively assessed whether the presence of a bull's-eye pattern of pancreatic-duct stones on multidetector computed tomography (MDCT) correlated with gene-mutation-associated pancreatitis (GMAP) and whether other signs suggestive of GMAP can be detected with MDCT.

MATERIALS AND METHODS

Forty-seven patients with chronic calcific pancreatitis underwent genetic testing for CFTR, SPINK1 and PRSS1 mutations and an MDCT scan of the abdomen. Qualitative analysis assessed the presence or absence of pancreatic-duct stones with bull's-eye appearance. Quantitative analysis included the number and maximum diameter of stones and the diameter of the main pancreatic duct.

RESULTS

Fifteen of 47 patients (32%) were positive for gene mutations (GMAP patients). The bull's-eye pattern was found in 10/15 patients (67%) with GMAP and in 4/32 (12%) patients with chronic pancreatitis not associated with GMAP (NGMAP; p<0.0001). The mean diameter of duct stones was 15 mm in patients with GMAP and 10 mm in patients with NGMAP (p<0.04).

CONCLUSIONS

The presence of duct stones with a bull's-eye pattern correlates with GMAP. Duct stones with diameter ≥15 mm are another sign suggestive of GMAP.

Italian consensus guidelines for chronic pancreatitis

This paper gives practical guidelines for diagnosis and treatment of chronic pancreatitis. Statements have been elaborated by working teams of experts, by searching for and analysing the literature, and submitted to a consensus process by using a Delphi modified procedure. The statements report recommendations on clinical and nutritional approach, assessment of pancreatic function, treatment of exocrine pancreatic failure and of secondary diabetes, treatment of pain and prevention of painful relapses. Moreover, the role of endoscopy in approaching pancreatic pain, pancreatic stones, duct narrowing and dilation, and complications was considered. Recommendations for most appropriate use of various imaging techniques and of ultrasound endoscopy are reported. Finally, a group of recommendations are addressed to the surgical treatment, with definition of right indications, timing, most appropriate procedures and techniques in different clinical conditions and targets, and clinical and functional outcomes following surgery.

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.

Impairment of changes in the diameter of the pancreatic portion of the superior mesenteric vein: an ultrasonographic sign of chronic pancreatitis or fibrosis

OBJECTIVE

A new ultrasonographic technique for detecting parenchymal stiffness of the pancreas is proposed. This technique measures changes in the diameter of the origin of the superior mesenteric vein (SMV) induced by deep inspiration. The origin of the SMV has extensive attachments to the pancreatic parenchyma; therefore, both physiologic enlargement and shrinkage of the venous lumen cannot occur without changes in the shape of the surrounding parenchyma. Therefore, increased parenchymal stiffness due to chronic pancreatitis (CP) may result in impaired changes in the venous diameter. To confirm this hypothesis, patients with CP and those with a normal pancreas were examined in this study.

METHODS

Twelve patients in each group were examined. Images of the origin of the SMV were obtained with a commercial ultrasound system. The smallest diameter of the SMV was measured during normal breathing. The patients were then asked to take a deep breath to increase the portal blood pressure followed immediately by the same measurements as performed during normal breathing, and the ratio of the change was calculated.

RESULTS

In the normal group, the diameter of the SMV changed by 79.5% +/- 43.8% (mean +/- SD), whereas a change of 1.4% +/- 7.3% was observed in the CP group. The difference between the two groups was statistically significant (P < .0001).

CONCLUSIONS

The physiologic change in the diameter of the origin of the SMV enhanced by deep inspiration may reflect the stiffness of the pancreatic parenchyma. Therefore, detection of an impaired diameter change may be useful for screening of CP.

[A review of current methods in the diagnostics of morphological changes in chronic pancreatitis]

Chronic pancreatitis is a disease with well-defined histopathology, however, the diagnosis is not based on the grading of histological changes, but on the features registered by the methods of morphological and functional diagnostic procedures. The correct diagnosis of chronic pancreatitis is easy in advanced stages, but difficult in early stages of the disease. In this review, we present the current methods used (echosonography, computer tomography, magnetic resonance, endoscopic retrograde cholangiopancreatography, endoscopic echosonography) in the diagnostics of chronic pancreatitis.

MDCT of acute mild (nonnecrotizing) pancreatitis: abdominal complications and fate of fluid collections

OBJECTIVE

The objective of our study was to describe the occurrence of local complications and the fate of fluid collections in milder forms of acute nonnecrotizing pancreatitis.

MATERIALS AND METHODS

Initial MDCT studies of 169 consecutive patients with mild acute pancreatitis and 203 follow-up CT examinations were reviewed. The fate of peripancreatic fluid collections was investigated, and the incidence and type of local complications were recorded and correlated to the CT grading system (A-E).

RESULTS

Complications developed in nine of 169 patients, for an incidence of 5.3%. All morbidity occurred in the subgroup of 73 patients with initial fluid collections, for an incidence of 12.3%. Follow-up CT examinations available in 51 of these 73 patients documented rapid fluid resolution in 35 cases (68.6%) and persistence of fluid more than 2 weeks from onset in seven asymptomatic patients (13.7%). Acute, life-threatening complications (hemorrhage, infection, perforation) occurred in five patients, for an incidence of 6.8% among the 73 patients with initial fluid collections, or 3.0% in the entire group of 169 patients. Five patients developed acute pseudocysts. Long-term follow-up studies discovered two patients with chronic pancreatitis and one with groove pancreatitis.

CONCLUSION

A small number of acute, life-threatening abdominal complications and chronic complications are expected to occur in patients with milder forms of acute nonnecrotizing pancreatitis presenting with fluid collections. In these patients, clinical monitoring and repeated imaging studies are recommended to document the resolution of fluid or the development of complications.

Suspected chronic pancreatitis with normal MRCP: findings on MRI in correlation with secretin MRCP

PURPOSE

To review pancreatic MRI findings and their relationship with estimated pancreatic exocrine function on secretin-stimulated MR cholangiopancreatography (S-MRCP) in patients with clinically suspected chronic pancreatitis and normal baseline MRCP findings.

MATERIALS AND METHODS

MRI findings of 26 patients with normal pancreatic duct diameter and without side branch ectasia on MRCP were evaluated. A single radiologist assessed pancreatic size, pancreatic signal intensity ratio (SIR), and arterial enhancement ratio (A/V) at head, body, and tail of the pancreas on T(1)-weighted fat-suppressed and serial contrast-enhanced images at a single session. Combined findings were graded with a composite score. Serial S-MRCP was performed at the same session with standard MRI. Correlation and differences between MRI findings and associated grade of duodenal filling (DF) or the degree of pancreatic duct caliber change (PDC) were analyzed.

RESULTS

Seven patients revealed normal and 19 patients abnormal MRI findings. Significant correlation was present between the degree of DF and mean values of pancreatic size (r = 0.748), SIR (r = 0.610), A/V (r = 0.466), composite score (r = 0.833), and PDC (r = 0.554) separately. PDC correlated with SIR (r = 0.413) and composite score (r = 0.452), but not with A/V or pancreatic size. Significant differences were present between normal and abnormal DF grades in terms of mean values of associated findings of size (P = 0.001), SIR (P = 0.008), A/V (P = 0.019), and PDC (P = 0.001).

CONCLUSION

Patients with clinically suspected chronic pancreatitis and normal MRCP findings may have a spectrum of MRI findings that correlate with the estimated pancreatic exocrine insufficiency on S-MRCP with the increasing number of combined findings.

Chronic pancreatitis: ultrasound, computed tomography, and magnetic resonance imaging features

Chronic pancreatitis is a progressive, irreversible inflammatory and fibrosing disease of the pancreas with clinical manifestations of chronic abdominal pain, weight loss, and permanent pancreatic exocrine and endocrine insufficiency. In the United States, a long history of heavy alcohol consumption is the most common cause of chronic pancreatitis. This review discusses the different modalities such as computed tomography, transabdominal and endoscopic ultrasound, magnetic resonance imaging/magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography available to image chronic pancreatitis, along with their advantages and limitations. In addition, topics such as groove pancreatitis and autoimmune pancreatitis are examined, along with a discussion of distinguishing chronic pancreatitis from pancreatic adenocarcinoma.

Ultrasonography of the pancreas. 4. Contrast-enhanced imaging

The introduction of contrast-enhanced ultrasonography (CEUS) has lead to great developments in the diagnostic capabilities of ultrasound. Second generation contrast media, characterized by harmonic responses at low mechanical index of the ultrasound beam, have already proven usefulness in the study of the liver but other abdominal organs can take advantage from the dynamic study during continuous ultrasonographic scans. The dynamic observation of the enhancement allows the perfect evaluation of the abdominal organs perfusion. The perfusion of the pancreas is well correlated to the semeiology of the gland parenchymography at CEUS. The study of the pancreas is a new and promising application of CEUS. CEUS can be used to better identify pancreatic lesions respect to conventional Ultrasound (US) or to characterize pancreatic lesions already visible at US. Moreover the staging of some pancreatic lesions can be improved by the use of contrast media. This article will review the clinical application of CEUS in the different pancreatic pathologies.

Ultrasonography of the pancreas. 1. Conventional imaging

Ultrasound imaging has made significant advances in recent years and plays an important role in the detection, characterization and staging of pancreatic diseases. Conventional ultrasonography (US) is a noninvasive imaging modality, which continues to be the first diagnostic step in the evaluation of the pancreas. Over its various decades of application, US have detected pancreatic pathology of great diversity. This article reviews the wide utility of US and the many examinations techniques, such as filling the stomach with water, changing the patient's position or suspending inspiration or expiration, allowing us to visualize all portions of the pancreas in a high percentage of patients.

Multiplanar reformations and minimum intensity projections using multi-detector row CT for assessing anomalies and disorders of the pancreaticobiliary tree

CT scan is regarded as the imaging modality of choice in patients with pancreaticobiliary ductal abnormalities. However, the axial orientation of the CT images provides only limited anatomical view of pancreaticobiliary ductal abnormalities. The technological advances of multi-detector row CT and three-dimensional image processing in workstations allows rapid image acquisition and a short postprocessing time. In particular, multiplanar reformations (MPR) and minimum intensity projections (MinIP) offer rapid and accurate images of the anatomy and abnormalities of the pancreaticobiliary tree. Moreover, MPR and MinIP help determine the relationship between the pancreaticobiliary ductal anatomy and the surrounding structures. This pictorial review illustrates the wide spectrum of images obtained by the MPR and MinIP of the anomalies and disorders of the pancreaticobiliary tree.

Diagnostic criteria for autoimmune chronic pancreatitis

Autoimmune chronic pancreatitis (AIP) is a clinically attractive entity because of its dramatic response to oral steroid therapy. Recently, as awareness of AIP is increasing, more cases are being reported. However, there are still no established worldwide diagnostic criteria for AIP. Since the Japan Pancreas Society (JPS) published diagnostic criteria for autoimmune chronic pancreatitis in the year 2002, increased attention toward this relatively new disease entity has enabled more cases of AIP to be correctly diagnosed. As previously unrecognized or misdiagnosed cases of autoimmune chronic pancreatitis are found, an increasing number of cases that are not in full accordance with the JPS diagnostic criteria are revealed. As a result, some groups have developed and cited their own criteria in the reporting of autoimmune chronic pancreatitis. The absence of consistent, uniform criteria has made comparison of different cases diagnosed under various guidelines difficult. In this review, we discuss and compare the four current sets of diagnostic criteria, focusing on their individual strengths and weaknesses.

The diagnostic criteria for autoimmune chronic pancreatitis: it is time to make a consensus

Autoimmune chronic pancreatitis (AIP) is increasingly being recognized as a worldwide entity. In 2002, the Japan Pancreas Society published diagnostic criteria for AIP. Since then, increased attention toward this relatively new disease entity has enabled more cases of AIP to be correctly diagnosed, allowing for proper management and avoidance of surgery. Retrospective inclusion of previously unrecognized or misdiagnosed cases of AIP has revealed an increasing number of cases that are not in full accordance with the Japanese diagnostic criteria. As a result, some groups have developed and cited their own criteria in the reporting of AIP, and the Japan Pancreas Society criteria have also undergone revision recently. The absence of consistent and uniform criteria has made the comparison of different cases diagnosed under various guidelines difficult. In this review, we discuss and compare the 4 current diagnostic criteria, focusing on their own strength and weakness with the aim of providing a framework for the development of unified criteria that represent an international consensus.

Mimicks of pancreatic malignancy in patients with chronic pancreatitis: correlation of computed tomography imaging features with histopathologic findings

Differentiation of chronic pancreatitis and pancreatic carcinoma can be a clinical and radiologic dilemma. Several patients with chronic pancreatitis can undergo unnecessary major abdominal surgery for benign lesions. This pictorial review illustrates the computed tomographic findings and histopathologic features of lesions mimicking pancreatic neoplasm in patients with chronic pancreatitis. Several benign lesions can simulate pancreatic malignancy in patients with chronic pancreatitis. Knowledge of the computed tomographic appearance of these benign entities is important to prevent unnecessary surgeries.

IRM et maladies pancréatiques

Magnetic resonance (MR) imaging of the pancreas has undergone a major change because it can provide noninvasive images of the pancreatic ducts and the parenchyma. MR cholangiopancreatography (MRCP) enables detection of anatomic variants such as pancreas divisum. Although contrast material-enhanced CT is still considered the gold standard in acute pancreatitis and for the detection of calcifications in chronic pancreatitis, MR imaging and secretin-enhanced MRCP are useful in evaluating pseudocysts and pancreatic disruption. The role of MR is still debated in pancreatic neoplasms except the cystic lesions where MR imaging provides critical information regarding the lesion's content and a possible communication with the pancreatic ducts. MRCP and MR of the pancreas are also useful in identifying other pancreatic diseases such as lymphoplasmocytic pancreatitis and groove pancreatitis.

Pancreaticobiliary Anomalies is the Leading Cause of Childhood Recurrent Pancreatitis

BACKGROUND/PURPOSE

To explore the etiology, age and gender distribution, complications, and prognosis of recurrent pediatric pancreatitis.

METHODS

Between 1993 and 2005, 92 children were hospitalized at the National Taiwan University Hospital with pancreatitis. Only 25 diagnosed with recurrent pancreatitis, based on two or more episodes of pancreatitis, elevated serum amylase and/or lipase levels > or = 3 times the upper limit of normal, radiographic evidence, and clinical symptoms, were enrolled.

RESULTS

A total of 85 episodes of pancreatitis in 25 patients (16 girls, 9 boys; mean age, 9.5 +/- 4.4 years; 3.4 +/- 1.9 episodes per person) were documented. The recurrence rate of pediatric pancreatitis was 27.2%. Recurrent pancreatitis was associated with pancreaticobiliary structural anomalies (n = 7), biliary stones or sludge (n = 4), hyperlipidemia (n = 3), pseudopapillary tumor of the pancreas (n = 2), trauma (n = 2), hypoxic encephalopathy with recurrent bacteremia and sepsis (n = 1), and idiopathic (n = 6). The age and gender distribution according to etiologies were not different (p = 0.301 for age, p = 0.137 for gender). Complications included cholangitis or cholestasis (16%), pancreatic necrosis (16%), pseudocyst formation (12%), shock (8%), hemorrhagic pancreatitis (4%), and diabetes mellitus (4%). No patient died of recurrent pancreatitis. Long-term morbidity after recurrent pancreatitis presented as gout, diabetes mellitus, non-alcoholic steatohepatitis, and chronic pancreatitis.

CONCLUSION

For children who suffer from recurrent pancreatitis, pancreaticobiliary structural anomalies should be considered first.

Mass-forming pancreatitis: Value of contrast-enhanced ultrasonography

AIM: To assess the utility of contrast-enhanced ultrasonography (CEUS) with a second-generation contrast medium in the differential diagnosis between mass-forming pancreatitis and pancreatic carcinoma.

METHODS: From our radio-pathology database, we retrieved all the patients affected by mass-forming pancreatitis or pancreatic carcinoma who underwent CEUS. We evaluated the results of CEUS in the study of the 173 pancreatic masses considering the possibilities of a differential diagnosis between mass-forming pancreatitis and pancreatic tumor by identifying the “parenchymographic” enhancement during the dynamic phase of CEUS, which was considered diagnostic for mass-forming pancreatitis.

RESULTS: At CEUS, 94% of the mass-forming pancreatitis showed intralesional parenchymography. CEUS allowed diagnosis of mass-forming pancreatitis with sensitivity of 88.6%, specificity of 97.8%, positive predictive value of 91.2%, negative predictive value of 97.1%, and overall accuracy of 96%. CEUS significantly increased the diagnostic confidence in the differential diagnosis between mass-forming pancreatitis and pancreatic carcinoma, with receiver operating characteristic curve areas from 0.557 (P = 0.1608) for baseline US to 0.956 (P < 0.0001) for CEUS.

CONCLUSION: CEUS allowed diagnosis of mass-forming pancreatitis with diagnostic accuracy of 96%. CEUS significantly increases the diagnostic confidence with respect to basal US in discerning mass-forming pancreatitis from pancreatic neoplasm.

Diagnostic criteria for autoimmune chronic pancreatitis revisited

Autoimmune chronic pancreatitis (AIP) is increasingly being recognized worldwidely, as knowledge of this entity builds up. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to the oral steroid therapy in contrast to ordinary chronic pancreatitis. Although many characteristic findings of AIP have been described, definite diagnostic criteria have not been fully established. In the year 2002, the Japan Pancreas Society published the diagnostic criteria of AIP and many clinicians around the world use these criteria for the diagnosis of AIP. The diagnostic criteria proposed by the Japan Pancreas Society, however, are not completely satisfactory and some groups use their own criteria in reporting AIP. This review discusses several potential limitations of current diagnostic criteria for this increasingly recognized condition. The manuscript is organized to emphasize the need for convening a consensus to develop improved diagnostic criteria.

Multidetector CT of the pancreas

CT is the primary imaging modality of the pancreas. This article reviews the multidector CT technique and its current status in the diagnosis of various pancreatic diseases. Special emphasis is given to the impact of multidetector CT and postprocessing imaging techniques on the staging of pancreatic adenocarcinoma.

Magnetic Resonance Imaging of the Pancreas: The Future Is Now

MR imaging has made significant advances in recent years, with an increasingly important role in the detection, characterization, and staging of pancreatic diseases. MRI is appealing as a noninvasive imaging modality as it can evaluate the pancreas, the vasculature, and the pancreaticobiliary ducts in a single examination. Advantages of MRI include its excellent soft tissue contrast resolution and anatomic detail and absence of ionizing radiation. This article reviews the utility of MRI and its use not only as a problem-solving tool but its potential use as a primary examination (similar to CT) in a wide variety of pancreatic diseases.

Dynamic contrast-enhanced MRI of the pancreas: initial results in healthy volunteers and patients with chronic pancreatitis

PURPOSE

To characterize pancreatic perfusion in volunteers and patients with chronic pancreatitis (CP) by dynamic contrast-enhanced (DCE) MRI.

MATERIALS AND METHODS

Pancreatic enhancement after bolus injection of Gd-DTPA with a three-dimensional ultrafast partial-Fourier radiofrequency (RF) spoiled gradient-echo (GE) acquisition was examined prospectively. An acquisition volume of the pancreatic parenchyma was obtained every 4.2 seconds during a single breath-hold in 31 volunteers and 19 patients with CP. We calculated the wash-in rate and a newly defined parameter, the "time-to-inflow deceleration" (TID). A statistical analysis of the differences between both groups was performed with the use of Student's t-test.

RESULTS

Significant differences in the TID and wash-in rate were found for the head and body of the pancreas: the TID was 22.4 sec +/- 4.4 sec and 23.5 sec +/- 6.1 sec in the pancreatic head and body of the healthy volunteers, and 29.8 sec +/- 8.6 sec and 29.4 sec +/- 3.8 sec in patients with CP. The wash-in rate was 96 +/- 37 sec(-1) and 101 +/- 27 sec(-1) in controls, and 62 +/- 17 sec(-1) and 75 +/- 27 sec(-1) in CP.

CONCLUSION

CP can be identified by semiquantitative changes on DCE-MRI. Whether DCE-MRI of the pancreas can be used to detect early CP remains to be validated.

Age-related changes in the pancreas identified by EUS: a prospective evaluation

BACKGROUND

EUS is an important modality for the diagnosis of pancreatic disease. An understanding of normal pancreatic ductal and parenchymal variation in asymptomatic individuals is essential to improve EUS accuracy. The primary aim of this study was to determine age-related pancreatic parenchymal and ductular changes identifiable on EUS in individuals with no history or symptoms of pancreaticobiliary disease. Secondary aims were to define demographic and clinical factors associated with identifiable pancreatic parenchymal and ductular changes, and to determine the main pancreatic-duct diameter and pancreatic-gland width according to age.

METHODS

Patients referred for either upper endoscopy or EUS for an indication unrelated to pancreaticobiliary disease were prospectively enrolled. Patients were stratified by age (<40, 40-60, >60 years). Each patient was assessed for the presence of EUS findings for chronic pancreatitis. Logistic regression was used to identify factors associated with an abnormality.

RESULTS

A total of 120 patients (63 men, 57 women; median age, 52 years, interquartile range [IQR] 40-61 years) were prospectively evaluated. At least one parenchymal and/or ductular abnormality was identified in 28% of the patients, with a trend of increasing abnormality with age: <40 years (23%), 40 to 60 years (25%), and >60 years (39%); p = 0.13. No patient had more than 3 abnormal EUS features. Hyperechoic stranding (n = 22) was the most common finding in all age groups. The odds for any abnormality in men (relative to women) was significantly higher (OR 2.9: 95% CI[1.2, 6.8], p = 0.01), with 38% of men and 18% of women having an abnormality. Smoking, low alcohol intake, body mass index, and endoscopic finding were not significantly associated with an abnormal EUS. The overall median pancreatic-gland width and main pancreatic duct diameter were 15 mm (IQR 6-25 mm) and 1.7 mm (IQR 0.9-4.3 mm), respectively.

CONCLUSIONS

The frequency of EUS abnormalities in patients without clinical evidence of chronic pancreatitis increases with age, particularly after 60 years of age. The threshold number of EUS criteria for the diagnosis of chronic pancreatitis is variable. However, the typically used standard of 3 or more criteria appears appropriate. A higher number of threshold criteria may be needed in males and to a lesser extent in patients over 40 years of age, which should be related to clinical history and other structural or functional studies. Ductal or parenchymal calculi, ductal narrowing, ductal dilatation, or more than 3 abnormalities appear to be more specific features for the EUS diagnosis of chronic pancreatitis at any age.

Autoimmune chronic pancreatitis

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis.