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

Vergleich von 2D- und 3D-Sequenzen für die MRCP

Magnetic resonance cholangio-pancreaticograpy (MRCP) is a non-invasive imaging modality of the pancreatico-biliary system which plays an increasingly important role in the clinical and diagnostic workup of patients with biliary or pancreatic diseases. The present review is designed to give an overview of the currently available and appropriate sequences, their technical background, as well as new developments and their relevance to the various clinical issues and challenges. The impact of the latest technical innovations, such as integrated parallel imaging techniques and navigator-based respiratory triggering, on the diagnostic capacities of MRCP is discussed. In this context, the individual value of RARE, T2w single shot turbo/fast spin echo (SSFSE) and the recently introduced 3D T2w turbo/fast spin echo sequences (T2w 3D-T/FSE) is reviewed. RARE imaging may be preferred in severely ill patients with limitations in cooperation, SSFSE is particularly effective in differentiating benign and malignant stenosis, and 3D-FSE offers additional advantages in the detection of small biliary concrements.

Quantification of pancreatic exocrine function with secretin-enhanced magnetic resonance cholangiopancreatography: normal values and short-term effects of pancreatic duct drainage procedures in chronic pancreatitis. Initial results

The aim of this study was to quantify pancreatic exocrine function in normal subjects and in patients with chronic pancreatitis (CP) before and after pancreatic duct drainage procedures (PDDP) with dynamic secretin-enhanced magnetic resonance (MR) cholangiopancreatography (S-MRCP). Pancreatic exocrine secretions [quantified by pancreatic flow output (PFO) and total excreted volume (TEV)] were quantified twice in ten healthy volunteers and before and after treatment in 20 CP patients (18 classified as severe, one as moderate, and one as mild according to the Cambridge classification). PFO and TEV were derived from a linear regression between MR-calculated volumes and time. In all subjects, pancreatic exocrine fluid volume initially increased linearly with time during secretin stimulation. In controls, the mean PFO and TEV were 6.8 ml/min and 97 ml; intra-individual deviations were 0.8 ml/min and 16 ml. In 10/20 patients with impaired exocrine secretions before treatment, a significant increase of PFO and TEV was observed after treatment (P<0.05); 3/20 patients presented post-procedural acute pancreatitis and a reduced PFO. The S-MRCP quantification method used in the present study is reproducible and provides normal values for PFO and TEV in the range of those obtained from previous published intubation studies. The initial results in CP patients have demonstrated non-invasively a significant short-term improvement of PFO and TEV after PDDP.

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.

Pancréatites chroniques et inflammatoires : apport des techniques d’imagerie en coupe

The role of diagnostic imaging in chronic and inflammatory pancreatitis is to detect structural changes of the ducts and pancreatic parenchyma, to assess the functional integrity of the gland, to detect associated complications, and to assist in management. These goals may be achieved using helical CT and MR imaging with secretin stimulation. In this review, the advantages of each technique are discussed and illustrated.

Efficacy of main pancreatic-duct endoscopic drainage in patients with chronic pancreatitis, continuous pain, and dilated duct

BACKGROUND

The aim of endoscopic treatment in patients with chronic pancreatitis is to achieve decompression of the pancreatic duct, because duct obstruction with increased pressure within the duct is one of the leading causes of pain in these patients. The majority of patients suffer from relapsing pain, thus making it difficult to evaluate the efficacy of therapy. The outcome of endoscopic treatment on pain has been evaluated in patients with continuous pain (present for more than 1 month, at least 5 days per week, requiring daily analgesic therapy) and dilated duct.

METHODS

Of 343 patients who underwent endotherapy for chronic pancreatitis in a 15-year period, 22 (6.4%)(19 men, mean age 48 years, alcohol abuse 14) had continuous pain and a dilated pancreatic duct.

RESULTS

Endotherapy was successful in all patients, with no procedure-related mortality and only mild complications. Pain disappeared, and analgesics could be discontinued in all patients immediately after endotherapy. Six patients are pain free after a mean period of 5.5 years. One pain-free patient died after 3.4 years from myocardial infarction. Five patients were successfully endoscopically re-treated for pain relapses. Four patients underwent surgery for frequent pain relapses after a mean period of 2.5 years. Six patients were lost to follow-up.

CONCLUSIONS

Endotherapy should be considered as the initial treatment of choice in patients with chronic pancreatitis, dilated duct, and continuous pain.

[Pancreas divisum and the dominant dorsal duct syndrome]

Pancreas divisum, the most frequent congenital malformation of the pancreas, results from the absence of embryologic fusion of the dorsal and ventral pancreatic ducts which keep an autonomy of drainage. The dorsal pancreatic duct is dominant and drains the major part of the pancreatic fluid through a non adapted accessory papilla. The high prevalence of pancreas divisum in patients presenting recurrent acute pancreatitis, the presence of obstructive pancreatitis electively located on the dorsal pancreatic duct and the results of the treatments targeted on the accessory papilla are the arguments pleading for the pathogenic character of the pancreas divisum. Currently, the diagnosis of pancreas divisum is based on magnetic resonance imaging. For symptomatic patients (after exclusion of patients with intestinal functional disorders), results of endoscopic sphincterotomy or surgical sphincteroplasty are favourable in 75% of patients with recurrent acute pancreatitis. They are worse in patients with chronic pain. Surgical sphincteroplasty must be discussed in the same manner as the endoscopic treatment for sometimes avoiding multiplication of the procedures.

Pancreatic Duct After Pancreatoduodenectomy:Morphologic and Functional Evaluation with Secretin-Stimulated MR Pancreatography

OBJECTIVE

The purpose of this study was to evaluate the usefulness of secretin-enhanced MR pancreatography in evaluating morphologic changes and pancreatic function after pancreatoduodenectomy.

SUBJECTS AND METHODS

Twenty patients who underwent pancreatoduodenectomy were evaluated with secretin MR pancreatography. Single-shot fast spin-echo T2-weighted dynamic MR pancreatograms were obtained before and every minute for 10 min after secretin injection. Image analysis included image quality for the visualization of the pancreatic duct and morphologic features of the pancreatic duct (side branches, ductal narrowing, irregular ductal contour, and patency of the anastomotic site). Pancreatic function was assessed using the Van de Kamer method and the fasting blood glucose and oral glucose tolerance tests. Jejunal filling was graded from the lowest amount of filling (grade 1) to normal filling (grade 3) on the last MR pancreatogram.

RESULTS

The visualization of the main pancreatic duct was significantly improved with dynamic MR pancreatography (p < 0.05). The anastomotic site was visualized in 14 patients (70%) on MR pancreatography after secretin administration (p < 0.05). No statistically significant improvement in other morphologic data was seen after secretin administration. The sensitivity, specificity, positive predictive value, and negative predictive value of reduced jejunal filling (grade 1) for assessment of reduced pancreatic exocrine function were 92%, 71%, 85%, and 83%, respectively. The relation between reduced jejunal filling (grade 1) and diabetes was statistically significant (p < 0.05).

CONCLUSION

The administration of secretin improves visualization of the pancreatic ducts and helps in the evaluation of remnant pancreatic function after pancreatoduodenectomy.

Magnetic resonance cholangiopancreatography

The current imaging technique and clinical application of MR cholangiopancreatography (MRCP) is reviewed. MRCP has evolved into a feasible method of non-invasively evaluating the pancreaticobiliary system and has considerable clinical utility. If endoscopic retrograde cholangiopancreatography (ERCP) is incomplete or has failed, or in patients with biliary and gastrointestinal surgical procedures, MRCP is a useful alternative modality. In the near future, MRCP may supplant diagnostic ERCP such that ERCP is reserved primarily for therapeutic interventions. Furthermore, when MRCP is performed in conjunction with abdominal MR and MR angiography, the 'all-in-one' examination can evaluate the solid organs and vessels of the abdomen as well as the ductal systems.

Fat malabsorption screening in chronic pancreatitis

OBJECTIVES

As the major metabolic complications of chronic pancreatitis are exocrine and endocrine dysfunction, leading to malabsorption and diabetes, the aims of this study were to screen patients with chronic pancreatitis for exocrine dysfunction, to correlate the prevalence of such dysfunction with the etiology and severity of pancreatitis, and to evaluate the effect of dysfunction on weight loss.

METHODS

Sixty patients were studied. In 44 patients, pancreatitis was alcoholic, and in 16, idiopathic. Patients' age, sex, alcohol consumption and smoking habits, duration of the disease, body mass index, and the presence of steatorrhea were recorded. The severity of pancreatitis was assessed by imaging procedures, including secretin-enhanced magnetic resonance cholangiopancreatography, and patients were classified according to the Cambridge system. Exocrine function was evaluated by the triolein breath test and acid steatocrit.

RESULTS

A significant positive correlation was found between breath test and steatocrit values. As a screening test for exocrine pancreatic dysfunction, the sensitivity of clinical steatorrhea was insufficient (38%). Of the 60 patients, 38 (63%) developed exocrine dysfunction within 5 yr of the onset of the pancreatitis and 56 (94%) after 10 yr. Moreover, undetected or untreated malabsorption had a harmful effect on weight, even in the absence of overt clinical steatorrhea.

CONCLUSIONS

To avoid nutritional deterioration, early screening for fat malabsorption should be recommended in chronic pancreatitis, whatever its etiology, using the acid steatocrit, a reliable, easy, and inexpensive test.

Use of the time-signal intensity curve from dynamic magnetic resonance imaging to evaluate remnant pancreatic fibrosis after pancreaticojejunostomy in patients undergoing pancreaticoduodenectomy

BACKGROUND

This study assessed the value of the time-signal intensity curve (TIC) obtained from dynamic magnetic resonance imaging (MRI) in the evaluation of remnant pancreatic fibrosis after pancreaticojejunostomy in patients undergoing pancreaticoduodenectomy.

METHODS

Two modes of pancreaticojejunostomy-duct-to-mucosa anastomosis (DMA; 24 patients) and pancreatojejunoserosal anastomosis (PJSA; 22 patients)-were used in 46 consecutive patients undergoing pancreaticoduodenectomy. All patients underwent dynamic contrast-enhanced MRI of the pancreas before pancreaticoduodenectomy. Retrospective review of the pancreatic magnetic resonance images and histological examination of the pancreas were performed, and the patterns of TICs from dynamic MRI were compared with the degree of pancreatic fibrosis. Dynamic MRI of the residual pancreas was carried out for 1-3 years after pancreaticoduodenectomy in 26 patients (14 DMA, 12 PJSA) who had a histologically verified normal pancreas with no fibrosis at the time of pancreaticoduodenectomy.

RESULTS

Evaluation of preoperative dynamic magnetic resonance images showed that a pancreatic TIC with a rapid rise to a peak followed by a rapid decline (type I) was characteristic of a normal pancreas without fibrosis. Pancreatic TICs with a slow rise to a peak followed by a slow decline or a plateau (types II and III) indicated a fibrotic pancreas. Postoperative pancreatic MRI demonstrated that six of 12 patients with a PJSA had a type II TIC, whereas 12 of 14 patients with a DMA had a type I curve (P = 0.046).

CONCLUSION

The TIC obtained from dynamic MRI is a reliable indicator of fibrosis in the remnant pancreas after pancreaticoduodenectomy. Use of a DMA was associated with a lower risk of pancreatic fibrosis 1-3 years after surgery than a PJSA.

Imaging diagnosis of pancreato-biliary diseases: A control study

AIM: To evaluate the clinical value of various imageological methods in diagnosing the pancreato-biliary diseases and to seek the optimal procedure.

METHODS: Eighty-two cases of pancreato-biliary diseases confirmed by surgery and pathology were analyzed. There were 38 cases of cholelithiasis, 34 cases of pancreato-biliary tumors and 10 other cases. The imageological methods included B-US, CT, ERCP, PTC, cross-sectional MRI and MR cholangiopancreatography (MRCP).

RESULTS: The accuracy rate of MRCP in detecting the location of pancreato-biliary obstruction was 100%. In differentiating malignant from benign obstruction, the sensitivity of the combination of MRCP and cross-sectional MRI was 82.3%, the specificity was 93.8%, and the accuracy rate was 89.0%. The accuracy rate for determining the nature of obstruction was 87.8%, which was superior to that of B-US (P = 0.0000) and CT (P = 0.0330), but there was no significant difference between direct cholangiopancreatography and the combination of MRCP and conventional MRI (P = 0.6666).

CONCLUSION: In most cases, MRCP can substitute direct cholangiopancreatography for diagnosis. The combination of MRCP and cross-sectional MRI should be considered as an important means in diagnosing the pancreato-biliary diseases, pre-operative assessment and post-operative follow-ups.

Magnetic resonance cholangiopancreatography. The fine art of bilio-pancreatic imaging

With the introduction of endoscopic retrograde cholangio-pancreatography in the early 1970s, gastroenterologists have a lot of diagnostic options in the biliopancreatic system to their disposal. Meanwhile, magnetic resonance cholangiopancreatography (MRCP) has become a competitive replacement for diagnostic ERCP with the advantage of avoiding complications related to endoscopic techniques. Mounting evidence suggests that both MRCP and MRI (magnetic resonance imaging) have a profound influence of diagnostic algorithms in a variety of hepatobiliary and pancreatic diseases.

The course of traumatic pancreatitis in a patient with pancreas divisum: a case report

BACKGROUND

The peculiar anatomy of pancreatic ducts in pancreas divisum (PD) may interfere with the development of acute chronic pancreatitis. In the presented case, PD influenced the evolution of lesions after pancreatic trauma.

CASE PRESENTATION

A 38 years old patient refferred to our hospital with recurrent episodes of mild pancreatitis during the last two years. The first episode occurred four months after blunt abdominal trauma. Endoscopic Retrograde Cholangiopancreatography, Magnetic Resonance Imaging of upper abdomen and Magnetic Resonance Cholangiopancreatography disclosed pancreas divisum, changes consistent with chronic pancreatitis in the dorsal pancreatic duct, atrophy in the body and tail of the pancreas and a pseudocyst in the pancreatic head, that was drained endoscopically.

CONCLUSION

Pancreas Divisum may interfere with the evolution of posttraumatic changes in the pancreas after blunt abdominal trauma.

MR cholangiopancreatography

Although MRCP is still an evolving technique, it has established itself as clinically useful and comparable with ERCP for the evaluation of various biliary or pancreatic ductal diseases. MRCP is not only comparable with ERCP in its diagnostic ability, but it has the tremendous advantage of being noninvasive. Furthermore, MR imaging is useful in patients with incomplete or failed ERCP, and in patients with certain biliary or gastrointestinal surgical procedures it is the imaging modality of choice. ERCP will remain an extremely important modality because of the great clinical importance for interventional biliary procedures with this technique. Nonetheless, MRCP may in the near future replace most of the diagnostic imaging of the biliary tree, with diagnostic results even more improved with further developments of hardware and technique.

MR cholangiopancreatography: evaluation of common pancreatic diseases

In the evaluation of common pancreatic diseases, MRCP is a noninvasive alternative to ERCP. Ductal anatomy can be ascertained without risk of complications. MRCP is valuable in defining common anatomic variants, determining the state of the pancreatic duct in pancreatitis, and characterizing neoplasms, especially combined with other MR imaging sequences. With the advent of MRCP, techniques requiring endoscopy and percutaneous access are largely reserved for histologic diagnosis and treatment, or for cases in which MRCP fails to establish a diagnosis.

Suspected early or mild chronic pancreatitis: enhancement patterns on gadolinium chelate dynamic MRI. Magnetic resonance imaging

PURPOSE

To assess whether measuring the pattern of pancreatic enhancement on gadolinium chelate dynamic magnetic resonance imaging (MRI) is helpful for diagnosis of suspected early or mild chronic pancreatitis.

MATERIALS AND METHODS

In this retrospective study, 24 patients with suspected early or mild chronic pancreatitis, classified by imaging criteria of equivocal chronic pancreatitis (ultrasound, computed tomography [CT] or ERCP) grading, had dynamic MRI that included unenhanced, arterial dominant, early venous, and late venous phases of contrast enhancement. Twenty patients without pancreatic diseases also had the dynamic sequence as a control group. The signal intensity was measured at the pancreatic head, body, and tail on all phases, and for each, the signal intensity ratio (SIR, the signal intensity in postcontrast divided by that in precontrast) was calculated. Two radiologists independently reviewed the images of the patients with suspected early or mild chronic pancreatitis for pancreatic morphologic abnormalities without knowing the results of signal intensity measurements.

RESULTS

On unenhanced images, there was no significant difference of signal intensity between control and pancreatitis groups (P < 0.05). In the pancreatitis group, but not in the control group, the unenhanced signal intensity of the pancreatic head and body were significantly higher than that of the tail (P < 0.05). In the control group, the greatest enhancement (highest SIR) after injection was in the arterial phase (1.89 +/- 0.31), significantly higher than that in the early venous phase (1.68 +/- 0.17, P < 0.01) and in the late venous phase (1.61 +/- 0.15, P < 0.001). The pancreatitis group, however, had an arterial phase SIR (1.65 +/- 0.23) that was significantly lower than its early venous phase SIR (1.75 +/- 0.22, P < 0.05) and lower than the arterial phase SIR of the control group (P < 0.01). The presence of an SIR less than 1.73 in the arterial phase and/or a delayed peak enhancement after contrast agent administration had a sensitivity and specificity of diagnosing early or mild chronic pancreatitis of 92% and 75%, respectively. This sensitivity was significantly higher than the sensitivity of 50% for diagnosis based on morphologic abnormalities (P < 0.05).

CONCLUSION

Measuring pancreatic signal intensity on gadolinium chelate dynamic MRI is helpful for diagnosing early or mild chronic pancreatitis, especially before apparent pancreatic morphologic or signal intensity changes are present.

Imaging of chronic pancreatitis

This article reviews the recognized findings of chronic pancreatitis on CT and endoscopic retrograde cholangiopancreatography. It also discusses more recently developed techniques including gadolinium-enhanced MR imaging, MR cholangiopancreatography, and endoscopic ultrasound. Variants of chronic pancreatitis and difficulties in differentiating pancreatic neoplasms from inflammatory pancreatic masses are also discussed.

MR cholangiopancreatography

In summary, over the past decade, MRCP has evolved not only as a feasible means of noninvasively evaluating the pancreaticobiliary tract but also as a technique with documented clinical utility. With the evolution of MRCP, there has been, by necessity, an evolution of ERCP. In fact, at some institutions MRCP has replaced diagnostic ERCP such that ERCP is reserved primarily for therapeutic interventions. When MRCP is performed in conjunction with abdominal MR and MRA, a comprehensive examination results that permits evaluation of the solid organs and vessels of the abdomen as well as the ductal systems.

MR imaging of the pancreas: a practical approach

This article reviews the current practical MRI techniques in assessment of the pancreas. With the comprehensive "one-stop-shopping" approach, the great majority of pancreatic diseases can be detected and characterized by the use of a combination of T1, T2-weighted, MRCP, and fat-suppressed T1-weighted dynamic post-gadolinium SGE sequences. This approach may provide the clinician with information regarding the site, nature, and staging of pancreatic tumor in a single setting. In many institutions worldwide, however, including our own, CT remains the main imaging method for the assessment of acute pancreatic diseases, due largely to its wide availability. MR imaging is reserved for the indications listed above, most importantly, the detection of small and non-organ-deforming pancreatic ductal adenocarcinoma, islet cell tumors, choledocholithiasis and pancreatic duct calculi, cholangiocarcinomas, and in cases of pancreatic head enlargement with no mass discernable on CT.

Idiopathic chronic pancreatitis in children: MR cholangiopancreatography after secretin administration

PURPOSE

To assess the accuracy of dynamic magnetic resonance (MR) cholangiopancreatography after secretin administration in detecting pancreatic duct abnormalities typical of early-onset idiopathic chronic pancreatitis in children with recurrent episodes of idiopathic acute pancreatitis.

MATERIALS AND METHODS

Fifteen children (mean age, 11.3 years; range, 6-17 years) with at least three recurrent episodes of idiopathic acute pancreatitis prospectively underwent MR cholangiopancreatography before and after secretin administration. Image analysis included visualization of side branches, ductal narrowing, endoluminal filling defects, irregular ductal contour, cavities, and pancreas divisum. All patients underwent endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

Dilated side branches were detected in three (20%) of 15 patients on MR cholangiopancreatograms obtained before secretin administration and in seven (47%) of 15 patients on images obtained after secretin administration. Ductal narrowing was detected in one (7%) of 15 patients on images obtained before secretin administration and in two (13%) of 15 patients on images obtained after secretin administration. Endoluminal filling defects in one (7%) of 15 patients were observed on MR cholangiopancreatograms obtained both before and after secretin administration. Irregular contour of the main pancreatic duct was present in four (27%) of 15 patients on MR cholangiopancreatograms obtained before secretin administration and in five (33%) of 15 patients on images obtained after secretin administration. Cavities and pancreas divisum were detected in one (7%) of 15 patients and in two (13%) of 15 patients, respectively, only on MR cholangiopancreatograms obtained after secretin administration.

CONCLUSION

Secretin improves the sensitivity of MR cholangiopancreatography in diagnosing early-onset idiopathic chronic pancreatitis.

Update on magnetic resonance cholangiopancreatography

MRCP is a useful tool in the diagnosis of a wide variety of pathologic entities including congenital anomalies, biliary obstruction and stricture, biliary calculi, pancreatitis, neoplasms, and trauma. ERCP and MRCP both have important roles in the management of patients with suspected pancreaticobiliary disease. Knowledge of the advantages and disadvantages of each technique is needed to determine the appropriate work-up of patients with these pathologies.

Dynamic MR pancreatography after secretin administration: image quality and diagnostic accuracy

OBJECTIVE

The objective of our study was to assess the improvement of image quality and diagnostic accuracy of secretin-enhanced MR pancreatography compared with conventional MR pancreatography.

SUBJECTS AND METHODS

Ninety-five patients were studied with a 1.5-T scanner using a T2-weighted single-slice fast spin-echo sequence. Image quality and diameter of the head, body, and tail portion of the pancreatic main duct, the accessory duct, and the side branches were assessed before and after IV administration of secretin. Diagnoses before and after secretin administration were evaluated in a blinded fashion and correlated to the final diagnoses based on endoscopic retrograde cholangiopancreatography (ERCP), intraoperative results, and clinical follow-up as the reference standard.

RESULTS

In patients with a normal pancreatic duct, the visualization of all portions of the main pancreatic duct and the accessory duct was significantly improved with dynamic MR pancreatography (p < or = 0.001). In patients with chronic pancreatitis, the visualization of the main duct was also significantly improved with dynamic MR pancreatography (p < or = 0.05). However, the visualization of the minor duct and the side branches was significantly improved only in patients showing no ductal stricture (p < or = 0.05), compared with those with ductal stricture (not significant). The overall sensitivity for the detection of chronic pancreatitis increased from 77% to 89% using secretin-enhanced MR pancreatography. A pancreas divisum was found in eight patients before and 13 patients after secretin administration. The overall negative predictive value of MR pancreatography increased from 84% to 98% after secretin administration.

CONCLUSION

Improvement in image quality after secretin stimulation increases the diagnostic value of MR pancreatography in patients with a normal or nondilated main pancreatic duct and may obviate invasive procedures such as ERCP.

ERCP and MRCP--when and why

Since the introduction of endoscopic retrograde cholangiopancreatography (ERCP) in the 1970s, gastroenterologists have a wide spectrum of diagnostic and therapeutic options in the biliopancreatic ductal system at their disposal. With its arrival in the 1990s, magnetic resonance cholangiopancreatography (MRCP) developed as a potent diagnostic tool in biliopancreatic pathology. Currently, MRCP is widely replacing diagnostic ERCP and thereby avoiding complications related to endoscopic technique.We summarize evidence-based data and demonstrate indications and differential indications for MRCP and ERCP in pancreatic disease. Complications related to the procedures and possible medical prevention are discussed. The feasibility of interventional endoscopy in pancreatic disease is reported in detail. The role of gastroenterologists in performing MRCP is outlined on the basis of practical examples.

Value of MR pancreatography in the evaluation of patients with chronic pancreatitis

AIM

To determine the diagnostic accuracy of magnetic resonance (MR) pancreatography and to define its role in the imaging work-up of patients with severe chronic pancreatitis.

MATERIAL AND METHODS

Thirty-two patients (13 men and 19 women; 15-84 years old; mean age, 48 years) with severe chronic pancreatitis diagnosed using cross-sectional imaging, examination using contrast medium (endoscopic retrograde cholangiopancreatography, pseudocyst injection) and/or surgical findings underwent MR pancreatography performed using a two-dimensional multi-slice fast spin echo technique. All patients underwent transabdominal pancreatic sonography and computed tomography (CT) was performed in 12 patients. Two observers independently assessed the MR pancreatograms for pancreatic duct dilatation and pancreatic duct abnormalities. Compared to the final diagnosis, the accuracy of MR pancreatography in revealing complications of chronic pancreatitis was calculated and its role in the radiological work-up of patients with chronic pancreatitis evaluated.

RESULTS

When compared to the final diagnosis, MR pancreatography showed the following sensitivity, specificity and diagnostic accuracy: for filling defects in pancreatic duct, 56-78%, 100% and 87-94%, respectively; for strictures, 75-88%, 92-96% and 88-94%, respectively; and for pseudocysts 100%, 100% and 100%, respectively. Filling defects were correctly diagnosed in all patients when MR pancreatography was interpreted in combination with cross-sectional imaging. Contrast pancreatography was required for the complete evaluation of strictures and communication with pseudocysts.

CONCLUSION

MR pancreatography is poorly sensitive but specific in revealing pancreatic duct filling defects and strictures. However, when MR pancreatography is interpreted in combination with sonography and CT, it provides sufficient information to plan therapy in the majority of patients.

Endoscopic retrograde cholangiopancreatography should no longer be used as a diagnostic test: the case in favour

The requirement for diagnostic endoscopic retrograde cholangiopancreatography has decreased considerably in the past 10 years. Alternative imaging techniques are now available for the diagnosis of bile duct stones, pancreatic and biliary tract malignancy and inflammatory diseases such as sclerosing cholangitis and chronic pancreatitis. The imaging techniques include endoscopic ultrasonography, magnetic resonance cholangiopancreatography and helical computed tomography. There is good evidence that these techniques have an accuracy comparable to endoscopic retrograde cholangiopancreatography in the diagnosis of diseases of the bile and pancreatic ducts. All of these methods are less invasive than endoscopic retrograde cholangiopancreatography and have extremely low or negligible complication rates. The choice of technique used depends on local availability and expertise. In future, endoscopic retrograde cholangiopancreatography will be reserved exclusively for therapeutic applications.

Using kinematic MR cholangiopancreatography to evaluate biliary dilatation

OBJECTIVE

The purpose of this study was to evaluate the usefulness of kinematic MR cholangiopancreatographic (MRCP) images as an aid in predicting the need for intervention in patients with biliary dilatation.

SUBJECTS AND METHODS

Fifty patients with suspected pancreaticobiliary disorders were separated into three groups. Group I patients had biliary dilatation with periampullary lesions (n = 16), group II patients had supraampullary obstructive lesions (n = 17), and group III patients had biliary dilatation without obstruction (n = 17). Twenty consecutive single thick-slice MRCP images were obtained in the 15 degrees or 30 degrees left anterior oblique coronal plane. Two radiologists jointly reviewed the images without knowledge of the final diagnosis. The numbers of images showing relaxation of the sphincteric segment and the configuration of the distal margin of the common bile duct for the three groups were compared.

RESULTS

Relaxation of the sphincteric segment was observed on the images of only two patients (12%) in group I but on the images of all patients in groups II and III, although not on all images. Lack of visualization of sphincteric relaxation on the kinematic MRCP images had a sensitivity of 88% and a specificity of 100% for the diagnosis of periampullary lesions. Most patients whose images did not show sphincteric relaxation required biliary intervention at the sphincter level.

CONCLUSION

Nonvisualization of sphincteric relaxation on kinematic MRCP indicates ampullary or periampullary lesions. Kinematic MRCP can be used to determine the necessity of biliary intervention in patients with biliary dilatation.

Permeability and functionality of pancreaticogastrostomy after pancreaticoduodenectomy with dynamic magnetic resonance pancreatography after secretin stimulation

BACKGROUND

The aim of this study was to evaluate pancreatogastrostomy (PG) permeability after duodenopancreatectomy (PD) and to determine a correlation with pancreatic endocrine and exocrine functions.

STUDY DESIGN

This prospective study included 19 patients who underwent PD with PG between 1992 and 1999. There were 12 men and 7 women, with a mean age of 58 years (range 35 to 76 years). The mean interval between operation and evaluation was 40.3 months (range 3 to 104 months). Indications for pancreatectomy were benign lesions (n = 13) or adenocarcinoma (n = 6). Histology of the pancreatic resection margin was normal in all patients with malignancy, and the pancreatic remnant was macroscopically normal without evidence of obstructive pancreatitis. Pancreatic exocrine and endocrine functions were respectively evaluated by fecal-1 elastase and fasting blood glucose concentrations. PG permeability was determined by secretin magnetic resonance cholangiopancreatography (Secretin-MRCP).

RESULTS

Anastomotic permeability was considered good in seven patients (group 1, 36.8%), moderately stenosed in six patients (group 2, 31.6%), significantly stenosed in four patients (group 3, 21.1%), and obstructed in two patients (group 4, 10.5%). Fecal-1 elastase concentration was decreased in 18 patients, with a mean concentration of 80 microg/g in group 1, 98 microg/g in group 2, 67 microg/g in group 3, and 0 microg/g in group 4. There was a statistically significant correlation between Secretin-MRCP group and fecal-1 elastase concentration. Results of fasting glucose estimation were normal for 14 of 19 patients. There was no correlation between pancreatic endocrine function and Secretin-MRCP group.

CONCLUSIONS

Exocrine pancreatic insufficiency was presented in 95% of the patients despite a PG permeability in 68.4%. These results may be explained in part by neutralization of pancreatic enzymatic secretions by gastric acid.

Endotherapy of early onset idiopathic chronic pancreatitis: results with long-term follow-up

BACKGROUND

Idiopathic chronic pancreatitis that presents at age 35 years or younger has been classified as early onset type and is often characterized by chronic severe pain. Endotherapy, with drainage of the main pancreatic duct, can lead to control of pain if ductal hypertension is an important cause. Long-term results of endotherapy in patients with early onset idiopathic chronic pancreatitis are reported herein.

METHODS

This retrospective study consists of 11 patients (6 men, 5 women; mean age 24.2 years, range 16-34 years) treated endoscopically in a 6.5-year period. The indication for treatment was pain in all patients and all had a dilated main pancreatic duct on pancreatography. The objectives of endoscopic treatment were to obtain good drainage of the pancreatic duct and complete clearance of ductal stones.

RESULTS

Treatment was successful in all patients with no procedure-related mortality and with mild complications. Seven patients remained free of pain relapses after a mean follow-up of 78.3 months (37-116 months). Seven relapses of pain were recorded in the remaining 4 patients. Endoscopic retreatment was successful in all cases. The difference between the number of hospitalizations during the year before treatment (mean 2.2, range 1-9) and the year after (mean 0.3, range 0-2) was statistically significant (p < 0.01). Statistical significance was maintained at 3 and 6 years' follow-up.

CONCLUSIONS

Endoscopic treatment could be regarded as the initial management of choice for patients with early onset idiopathic chronic pancreatitis.

Pancreatic duct: morphologic evaluation with MR cholangiopancreatography after secretin stimulation

PURPOSE

To evaluate the pancreatic duct after administration of secretin.

MATERIALS AND METHODS

Single-shot turbo spin-echo T2-weighted dynamic magnetic resonance cholangiopancreatography (MRCP) was performed in 85 patients who did not have pancreatic diseases (group 1) and in 50 patients who had focal severe stenosis of the main pancreatic duct (group 2). The visualization and diameter of the pancreatic duct before and after secretin administration were assessed.

RESULTS

In group 1, after secretin administration, the best visualization of the main pancreatic duct in the head, body, accessory pancreatic duct, and branch ducts was achieved in 4.7 minutes +/- 1.6 (SD), 4.8 minutes +/- 1.6, 4.6 minutes +/- 1.6, and 4.7 minutes plus minus 1.3, respectively. Improvement in the delineation of the main pancreatic duct in the head (78 [92%] patients), body (80 [94%] patients), accessory pancreatic duct (35 [41%] patients), and branch ducts (14 [16%] patients) was achieved. Overlap of fluid in the organ and the pancreatic duct was observed in 20 (24%) of 85 patients. Overlap was especially observed after 5 minutes of secretin injection. In group 2, the best visualization of the distal main pancreatic duct was achieved 4.9 minutes +/- 1.4 after secretin administration. Improvement in the delineation of the distal main pancreatic duct was achieved in 17 (85%) of 20 patients.

CONCLUSION

MRCP is best performed during the first 5 minutes after secretin administration.

Magnetic resonance imaging in patients with pancreatitis: evaluation of signal intensity and enhancement changes

PURPOSE

To evaluate the utility of unenhanced and enhanced T1-weighted fat-suppressed (T1-FS) magnetic resonance imaging (MRI) in detecting pancreatitis.

MATERIALS AND METHODS

1.5-T MRI was performed in 25 patients with acute and 23 patients with chronic pancreatitis and in 20 control subjects without known pancreatic disease. T1-FS spin-echo and contrast-enhanced arterial-predominant (DYN1) and portal-predominant (DYN2) fast multiplanar spoiled gradient-echo (FMPSPGR) sequences were evaluated. These three sets of images were evaluated both subjectively for decreased or heterogeneous signal intensity (rating scale, 0-3) and objectively (region of interest (ROI)) in the head, body, and tail of the pancreas, in each patient.

RESULTS

Good correlation between subjective assessment and objective data was demonstrated. The T1-FS sequence showed an abnormality with greater frequency (T1-FS > DYN1, 81/144 scores; T1-FS = DYN1, 63/144 scores; T1-FS < DYN1, 0/144 scores) and magnitude (average subjective score, 2.48 vs. 1.74; P < 0.0003) than that of the contrast-enhanced FMPSPGR (decreased or heterogeneous enhancement). The overall sensitivity and specificity of MRI was 92% and 50%, respectively. On the basis of signal intensity and enhancement, MRI was not able to differentiate acute from chronic pancreatitis.

CONCLUSION

MRI was highly sensitive for disease detection, particularly using the T1-FS sequence, but using the sequences described, was not able to differentiate acute from chronic pancreatitis.

MR imaging of the pancreas: a pictorial tour

Magnetic resonance (MR) imaging of the pancreas has undergone a major change because of its capability of providing noninvasive images of the pancreatic ducts, cross-sectional images of the parenchyma analogous to computed tomography (CT) images, and angiographic depiction of blood vessels. Recent technical issues include the use of half-Fourier T2-weighted pulse sequences and the administration of secretin for MR cholangiopancreatography (MRCP). Secretin improves pancreatic duct and side-branch delineation and the detection of anatomic variants such as pancreas divisum. It allows monitoring of pancreatic flow dynamics and evaluation of pancreatic exocrine function. Although contrast material--enhanced CT is still considered the standard of reference in severe acute pancreatitis and for the detection of calcifications in chronic pancreatitis, in patients referred for suspicion of pancreatic disease or with recurrent acute pancreatitis, MR imaging and secretin-enhanced MRCP are useful after unenhanced CT suggests the cause of disease. In advanced inflammatory disease, MR imaging and secretin-enhanced MRCP are useful for planning surgery or therapeutic endoscopy and for follow-up studies after therapy. MR imaging in combination with secretin-enhanced MRCP and MR angiography is useful in identifying pancreatic malignancies and in establishing resectability.

Evaluation of pancreatic exocrine function by secretin-enhanced magnetic resonance cholangiopancreatography

AIM

To assess the feasibility and usefulness of secretin-enhanced magnetic resonance cholangiopancreatography (S-MRCP) for evaluation of pancreatic exocrine function.

METHODOLOGY

S-MRCP was performed in 20 patients with mild (n = 8) or severe (n = 12) chronic pancreatitis (according to the grade of exocrine pancreatic insufficiency indicated by the Lundh test) and in 10 volunteers without pancreatic disease. MRCP images were evaluated before and 10 minutes after the intravenous administration of 0.5 IU/kg secretin. The changes in pancreatic tissue T2 signal intensity and duodenal filling after the injection of secretin were determined by means of S-MRCP. The S-MRCP findings were then compared with those of the Lundh test.

RESULTS

The pancreatic T2 signal intensity showed a significant elevation after secretin administration in the volunteers and in the patients with mild or severe chronic pancreatitis. This elevation was significantly lower in patients with mild and severe chronic pancreatitis than in the volunteers (66.85+/-15.77 and 24.45+/-5.85 vs. 200.0+/-45.07, respectively). After administration of secretin. the diameter of the duodenum was significantly increased in all three groups. This duodenal filling was significantly reduced in patients with mild or severe exocrine pancreatic insufficiency as compared with the volunteers (4.12+/-1.33 and 1.70+/-0.77 vs. 15.38+/-1.73, respectively). There was no significant difference in pancreatic T2 signal intensity changes or in duodenal filling in patients with mild or severe exocrine pancreatic insufficiency. There were significant correlations between the pancreatic T2 signal intensity changes and the duodenal filling and the results of the Lundh test (r = -0.616 and -0.78).

CONCLUSION

These results demonstrate that the administration of secretin increases the T2 signal intensity of the pancreatic tissue and the diameter of the duodenum to different extents in normal subjects and in patients with chronic pancreatitis. This suggests that S-MRCP can provide information of value in the assessment of an exocrine pancreatic insufficiency.

Pancreatitis: etiology, diagnosis, and management

Inflammation of the pancreas (pancreatitis) has many presentations in children and adolescents, ranging from intrauterine congenital onset with sequelae of early exocrine pancreatic insufficiency as in the diseases of cystic fibrosis and Shwachman-Diamond syndrome to postnatal onset as a consequence of embryologic anomalies affecting pancreatic drainage postulated to exist in pancreas divisum, or of traumatic, obstructive, hemodynamic, metabolic or biochemical insults. The etiology is often elusive with up to 30% of cases being idiopathic. Modern imaging modalities of endoscopic ultrasonography and magnetic resonance cholangiopancreatography extend the diagnostic power of conventional abdominal ultrasonography and computed tomography. In addition, there is increasing pediatric experience with endoscopic retrograde cholangiopancreatography. Medical management remains supportive, with optimal timing and indications for surgery in cases of pancreatic necrosis and pseudocyst assessed. Three temporal patterns of pancreatitis appear in children: acute pancreatitis, recurrent acute pancreatitis, and chronic pancreatitis. Acute pancreatitis is of abrupt onset, often attributable to a specific cause, and of variable severity and duration but self-limited with eventual resolution. Acute attacks of pancreatitis recurring after periods of remission characterize acute recurrent pancreatitis and indicate an intrinsic problem or susceptibility. Chronic pancreatitis is present in most of these cases in which pancreatic inflammation and destruction never completely remits.

Chronic pancreatitis: diagnosis, classification, and new genetic developments

The utilization of recent advances in molecular and genomic technologies and progress in pancreatic imaging techniques provided remarkable insight into genetic, environmental, immunologic, and pathobiological factors leading to chronic pancreatitis. Translation of these advances into clinical practice demands a reassessment of current approaches to diagnosis, classification, and staging. We conclude that an adequate pancreatic biopsy must be the gold standard against which all diagnostic approaches are judged. Although computed tomography remains the initial test of choice for the diagnosis of chronic pancreatitis, the roles of endoscopic retrograde pancreatography, endoscopic ultrasonography, and magnetic resonance imaging are considered. Once chronic pancreatitis is diagnosed, proper classification becomes important. Major predisposing risk factors to chronic pancreatitis may be categorized as either (1) toxic-metabolic, (2) idiopathic, (3) genetic, (4) autoimmune, (5) recurrent and severe acute pancreatitis, or (6) obstructive (TIGAR-O system). After classification, staging of pancreatic function, injury, and fibrosis becomes the next major concern. Further research is needed to determine the clinical and natural history of chronic pancreatitis developing in the context of various risk factors. New methods are needed for early diagnosis of chronic pancreatitis, and new therapies are needed to determine whether interventions will delay or prevent the progression of the irreversible damage characterizing end-stage chronic pancreatitis.

Pancreas divisum and "santorinicele": diagnosis with dynamic MR cholangiopancreatography with secretin stimulation

PURPOSE

To evaluate the usefulness of magnetic resonance (MR) cholangiopancreatography (MRCP) before and after secretin administration in diagnosing santorinicele in patients with pancreas divisum.

MATERIALS AND METHODS

One hundred seven patients suspected of having pancreatic disease underwent MRCP before and after secretin administration (S-MRCP). S-MRCP images were evaluated for pancreas divisum and santorinicele and for size of the main pancreatic duct and santorinicele. The onset of duodenal filling was calculated on dynamic S-MRCP images.

RESULTS

Pancreas divisum was detected in five (5%) of 107 patients at MRCP and in 10 (9%) of 107 patients at S-MRCP. Santorinicele was detected in three (21%) of 14 patients at MRCP and in an additional four (seven [50%] of 14) patients at S-MRCP in patients with pancreas divisum. Santorinicele was confirmed in six of seven patients at endoscopic retrograde cholangiopancreatography (ERCP); in one of seven patients, ERCP was unsuccessful. The duct of Santorini was significantly (P: <.05) larger in the pancreatic head in patients with pancreas divisum and santorinicele (3.6 mm) compared with those with only pancreas divisum (2.2 mm). A noteworthy reduction in size of the pancreatic duct (26%) and of the santorinicele (63%) was observed after sphincterotomy. The onset of duodenal filling was delayed significantly in patients with santorinicele (2.1 vs 1.3 minutes; P: <.05).

CONCLUSION

S-MRCP helps in identifying pancreas divisum and santorinicele, which may be the cause of impeded pancreatic outflow.