Copyright ©2010 Baishideng. All rights reserved.
World J Gastrointest Endosc. Apr 16, 2010; 2(4): 107-111
Published online Apr 16, 2010. doi: 10.4253/wjge.v2.i4.107
Endoscopic ultrasonography and idiopathic acute pancreatitis
Juan J Vila
Juan J Vila, Endoscopy Unit, Gastroenterology Department, Hospital de Navarra, Pamplona 31008, Spain
Author contributions: Vila JJ contributed solely to this paper.
Correspondence to: Juan J Vila, MD, Endoscopy Unit, Gastroenterology Department, Hospital de Navarra, Pamplona 31008, Spain. juanjvila@gmail.com
Telephone: +34-848-422114 Fax: +34-848-422303
Received: March 13, 2009
Revised: March 31, 2010
Accepted: April 7, 2010
Published online: April 16, 2010


Idiopathic acute pancreatitis is a diagnostic challenge for gastroenterologists. The possibility of finding a cause for pancreatitis usually relies on how far the diagnostic study is taken. Endoscopic explorations such as endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography can help to determine the cause of pancreatitis. Furthermore, microscopic bile examination and magnetic resonance cholangiopancreatography can also be helpful in the work up of these patients. In this article an approximation to the diagnostic approach to patients with idiopathic acute pancreatitis is made, taking into account the reported evidence with which to choose between the different available explorations.

Key Words: Endosonography, Cholangiopancreatography, Endoscopic retrograde, Cholangiopancreatography, Magnetic resonance, Microscopic bile examination, Idiopathic pancreatitis, Acute, Diagnosis


Acute pancreatitis might be defined as an inflammatory process of the pancreas clinically characterized by upper abdominal pain and elevated levels of pancreatic enzymes in the blood. In up to 10% of patients with a single episode of acute pancreatitis and in 30% of patients with acute recurrent pancreatitis, the aetiology is not found after the initial examination. Initial work up should include a detailed clinical history with records of recent infectious diseases, abdominal traumas or surgery; personal records of systemic diseases and ethanol or medicine intake; serum calcium, triglycerides levels, liver enzymes and autoantibodies (ANA, IgG4, rheuma factor); and at least one transabdominal ultrasonography although two are advisable. These patients are diagnosed with idiopathic acute pancreatitis (IAP)[1,2].

This situation represents a diagnostic challenge since in many cases the possibility of finding a cause for the pancreatitis depends directly on how deep the etiological search is made. Thus, when more accurate explorations are performed, gallbladder microlithiasis, sphincter of Oddi dysfunction, pancreas divisum or chronic pancreatitis is usually found. Less commonly, pancreatic tumours or cysts, anatomic anomalies such as a long pancreatobiliary junction (> 15 mm), annular pancreas, choledococele, a duodenal duplication cyst and a periampullary diverticulum can also be found as the cause of the acute pancreatitis bout. In the absence of mechanical and anatomic causes of acute pancreatitis in patients under 40 years of age, gene mutations such as mutations of the cationic trypsinogen gene, in the serine protease inhibitor Kazal type I or in cystic fibrosis gene must be considered as a possible cause of the IAP.

Autoimmune pancreatitis, a pancreatic disorder characterized by imaging criteria (enlargement of the pancreatic gland, diffuse narrowing of Wirsung duct with an irregular wall), laboratory criteria (elevation in IgG4 serum levels and positive autoantibodies) and histopathologic criteria (marked lymphoplasmacytic infiltration and dense fibrosis)[3] has been more frequently diagnosed recently. Using a cut off value of 135 mg/dL, the sensitivity and specificity of the serum IgG4 for distinguishing autoimmune pancreatitis from pancreatic cancer are 95% and 97% respectively[4]. Recent studies indicate that two different types of AIP exist: Type I which is predominantly found in Western Europe and the United States (IgG4 negative) and Type II which is more frequently found in Asia[5,6].

It is of great importance to identify the cause of pancreatitis because if it is not corrected recurrence is common; up to 70% depending on the cause[7]. Moreover, the mortality rate for acute pancreatitis is between 4% and 9% but can be higher for IAP[8].

In order to find the cause of the IAP, several explorations such as Endoscopic Retrograde Cholangio-Pancreatography (ERCP), Magnetic Resonance Cholangio-Pancreatography (MRCP), Microscopic Bile Examination (MBE) or Endoscopic Ultrasonography (EUS) can be performed. By performing one of these explorations or a combination, an etiological diagnosis can be made in up to 90% of cases of IAP.

However, some considerations must be made regarding the etiological diagnosis of patients with IAP.


ERCP has been the first choice of diagnostic procedures in these patients for over three decades with a diagnostic yield of up to 80% but with a rate of potentially severe complications of 10%-15%[9,10]. An important advantage of ERCP is that it is possible to perform therapeutic manoeuvres necessary in up to 75% of these patients. Taking into account its morbidity rate, some authors recommend an ERCP only after the second episode of IAP or after the first in severe IAP[7,11]. Other authors support the indication of ERCP systematically after the first episode of IAP[12].

In patients with gallbladders, the most frequent cause of the IAP is microlithiasis which is present in up to 80% of these patients[2,13]. The exploration considered as the gold-standard to diagnose microlithiasis is currently the MBE[14] with a sensitivity of 65%-90% and a specificity of 88%-100%[15]. However, this exploration has some drawbacks which should be noted. In 29%-50% of patients with known gallbladder lithiasis, the MBE is falsely negative[16]. Moreover, it is a time consuming exploration which might take up to one hour. It is also not feasible in up to 20% of patients due to it being impossible to place the nasoduodenal probe in the second duodenal portion, aspiration of inadequate material or the patient’s intolerance. This rate of exploration failure has also been reported by other groups[17].

Dahan et al[18] compared the diagnostic accuracy of EUS with MBE in detecting microlithiasis in patients with IAP or abdominal pain mimicking a biliary colic with transabdominal ultrasonography within normal limits. Results were significantly better with EUS compared to MBE.

However, to my knowledge, these results have not been confirmed by other groups. In a prospective blinded comparative study, we found similar accuracies for EUS and MBE (100% vs 95%, P > 0.05) in diagnosing the presence of microlithiasis but EUS diagnosed the presence of other pancreatic diseases which could be responsible for the acute pancreatitis bout in 25% of patients[19]. Therefore, MBE should not be currently considered as a first line procedure in the examination of patients with IAP.

Recently EUS has proved to have a diagnostic accuracy between 60% and 80%[20-27] in patients with IAP similar to ERCP but with a lower complication rate comparable to gastroscopy[28]. This gives an idea of the clinical impact of EUS on the management of these patients. Theoretically, with EUS we might be able to diagnose the majority of possible causes of IAP stated previously. Besides the high diagnostic accuracy for detecting gallbladder lithiasis and microlithiasis[29], EUS is considered one of the most accurate techniques in diagnosing chronic pancreatitis[30]. The presence of at least 5 endosonographic criteria of chronic pancreatitis offers a sensitivity of 60% and a specificity of 83% to diagnose chronic pancreatitis with a high positive predictive value, an excellent correlation with ERCP for moderate and severe chronic pancreatitis (κ = 0.82) and a good interobserver correlation (κ = 0.45)[31,32]. On the other hand, the presence of less than 3 endosonographic criteria has a high negative predictive value for chronic pancreatitis (85%)[31].

EUS has also proved its value to diagnose biliary and pancreatic tumours with a diagnostic accuracy higher than CT especially in those tumours smaller than 2.5 cm in diameter[33,34] with a negative predictive value close to 100%[35]. Furthermore, in these cases EUS allows a correct staging with a resectability accuracy of 67%[36] and the ability to obtain a cytological diagnosis with a sensitivity of around 89%, a specificity of 99% and a diagnostic accuracy of 96%[37].

EUS can also diagnose the presence of pancreatic cysts which might be responsible for the acute pancreatitis bout, especially those cysts communicated with the pancreatic duct such as Intraductal Papillary Mucinous Neoplasm (IPMN)[38]. This entity can cause recurrent pancreatitis, probably by means of intermittent pancreatic duct obstruction related to mucus plugs. EUS is fairly reliable in differentiating IPMN from chronic pancreatitis[39]. Mucinous and serous cystic neoplasms rarely communicate with the pancreatic duct and therefore rarely cause pancreatitis. Thus, EUS can help to distinguish between serous and mucinous cystic neoplasms by the morphological aspects, although no endosonographic features have proved to be consistently reliable for distinguishing benign from malignant lesions[40]. Furthermore, EUS offers the possibility of performing FNA and analysing the cyst fluid with determination of tumor antigens, fluid viscosity, mucin staining, amylase concentration, analysis of genetic mutations associated with tumours and cytology. These determinations may improve diagnostic accuracy[41]. However, EUS findings by themselves are not accurate enough to definitively diagnose the nature of the pancreatic cystic lesion and cyst fluid cytological or laboratory analysis may not provide a reliable and definitive diagnosis which is sometimes impossible until surgical excision is done[42].

Besides the diagnostic accuracy, the possibility of performing sphincterotomy on EUS[43] has recently been described. This therapeutic role of EUS should be confirmed in the next few years.

MRCP is a non invasive exploration which has also proved its value in diagnosing entities responsible for an acute pancreatitis bout such as chronic pancreatitis, sphincter of Oddi dysfunction, anatomic anomalies and choledocolithiasis[44,45]. Studies testing the role of MRCP in the setting of IAP are scarce but it can be useful, especially when MRCP is combined with secretin test showing a positive predictive value for the diagnosis of sphincter of Oddi dysfunction of 100%, but with a disappointing negative predictive value of 64%[44]. However, to my knowledge, MRCP and EUS have never been prospectively compared in this setting.

The main support for performing EUS in patients with IAP is its high diagnostic accuracy especially in diagnosing the presence of microlithiasis[34] which is the most frequent finding. In these cases, performing a cholecystectomy reduces the recurrence of pancreatitis from 66%-75% in untreated patients to 10% in patients who undergo cholecystectomy[2,13,17]. EUS is a relatively invasive technique with a minimum but present risk of complications and it might be more uncomfortable for the patient. On the other hand, MRCP has not yet proved its value in patients with IAP although it can diagnose the majority of causes for pancreatitis except for microlithiasis.

Taking this background into account, in my opinion but not shared by other authors[46], it is out of discussion that the first diagnostic exploration for patients with IAP and gallbladder in situ is EUS. Debate must be open in patients already cholecystectomized, in whom chronic pancreatitis, sphincter of Oddi dysfunction and pancreas divisum are the most frequent etiological findings and MRCP has demonstrated good accuracy to diagnose these entities[45]. However, EUS has proved to be superior in detecting choledocholithiasis smaller than 5 mm[47,48]. Therefore, when choledocholithiasis is strongly suspected, a negative MRCP should be followed by EUS. So the decision to perform EUS or MRCP as the first choice diagnostic procedure in cholecystectomized patients must be made by taking into account other factors. These factors include local expertise and personal records of patients such as claustrophobia, gastric surgery etc. ERCP should remain as a therapeutic exploration when necessary[46].

Unfortunately, to my knowledge, there are still no prospective reports comparing the diagnostic accuracy of EUS with MRCP on patients with IAP. We are currently performing a prospective double blinded study comparing the diagnostic yield of EUS and MRCP in order to clarify their role in the diagnostic work up of patients with IAP.


There is some controversy in the literature about this subject. Some authors have questioned the efficacy of EUS in cases of relapsing pancreatitis[49]. This topic has been evaluated in previously published papers comparing the diagnostic yield of EUS in IAP patients with a single episode or a recurrent disease, proving that the diagnostic yield of EUS does not significantly change between both groups[23-25]. So, it seems that the diagnostic yield of EUS is similar both in patients with a single episode of pancreatitis and in patients with recurrent disease and is therefore useful in both situations. This opinion is shared by other authors[50,51].


The best moment to perform the EUS exploration in patients with IAP is another confusing and difficult question to answer and there are as many possibilities as published reports. Norton et al[20] perform EUS when patients resume food intake; Liu et al[22] perform EUS when the acute pancreatitis bout has resolved normally during admission; Tandon et al[23] when symptoms of acute pancreatitis have subsided, normally 2 or 3 wk after the acute phase; and Yusoff et al[25] perform the exploration at least 4 wk after the acute episode in order to assure that acute pancreatic parenchymal changes have resolved when EUS is performed.

In our endoscopy unit we agree with the latter author and perform EUS at least four weeks after hospital discharge in order to assure a complete resolution of the acute parenchymal alterations which would lead to misdiagnosis. Another reason to do so is to differentiate gallbladder microlithiasis related to acute pancreatitis fasting which would be a consequence of the disease from previously present microlithiasis which would be the cause of the disease. To perform EUS at least four weeks after hospital discharge has two major disadvantages: firstly, an existing prepapillar choledocholithiasis might not be diagnosed with the potential of a re-bout. Secondly, since there is a potential risk of losing the patient for follow up after clinical improvement, a small pancreatic tumor might be missed.

In conclusion, EUS offers a high diagnostic yield in patients with IAP and should be considered the first diagnostic procedure to perform in these patients, even in those with a single episode. MRCP can also be valuable in this setting, but its role should be defined in prospective comparative studies, especially in cholecystectomized patients.


Peer reviewers: Everson Luiz de Almeida Artifon, MD, PhD, FASGE, University of Sao Paulo School of Medicine, Rua Guimaraes Passos Zc-04107030, Brazil; Claus Schäfer, Assistant Professor of Internal Medicine/Gastroenterology, Medical Clinic II - Campus Grosshadern, University of Munich, Munich 81377, Germany

S- Editor Zhang HN L- Editor Roemmele A E- Editor Liu N

1.  Steinberg W, Tenner S. Acute pancreatitis. N Engl J Med. 1994;330:1198-1210.  [PubMed]  [DOI]
2.  Lee SP, Nicholls JF, Park HZ. Biliary sludge as a cause of acute pancreatitis. N Engl J Med. 1992;326:589-593.  [PubMed]  [DOI]
3.  Members of the Criteria Committee for Autoimmune Pancreatitis of the Japan Pancreas Society. Diagnostic criteria for autoimmune pancreatitis by the Japan Pancreas Society. J Jpn Pan Soc. 2002;17:585-587.  [PubMed]  [DOI]
4.  Hamano H, Kawa S, Horiuchi A, Unno H, Furuya N, Akamatsu T, Fukushima M, Nikaido T, Nakayama K, Usuda N. High serum IgG4 concentrations in patients with sclerosing pancreatitis. N Engl J Med. 2001;344:732-738.  [PubMed]  [DOI]
5.  Okazaki K, Kawa S, Kamisawa T, Ito T, Inui K, Irie H, Irisawa A, Kubo K, Notohara K, Hasebe O. Japanese clinical guidelines for autoimmune pancreatitis. Pancreas. 2009;38:849-866.  [PubMed]  [DOI]
6.  Chari ST, Longnecker DS, Klöppel G. The diagnosis of autoimmune pancreatitis: a Western perspective. Pancreas. 2009;38:846-848.  [PubMed]  [DOI]
7.  Bank S, Indaram A. Causes of acute and recurrent pancreatitis. Clinical considerations and clues to diagnosis. Gastroenterol Clin North Am. 1999;28:571-589, viii.  [PubMed]  [DOI]
8.  Kohut M, Nowak A, Nowakowska-Duława E, Kaczor R, Marek T. The frequency of bile duct crystals in patients with presumed biliary pancreatitis. Gastrointest Endosc. 2001;54:37-41.  [PubMed]  [DOI]
9.  Mallery JS, Baron TH, Dominitz JA, Goldstein JL, Hirota WK, Jacobson BC, Leighton JA, Raddawi HM, Varg JJ 2nd, Waring JP. Complications of ERCP. Gastrointest Endosc. 2003;57:633-638.  [PubMed]  [DOI]
10.  Coyle WJ, Pineau BC, Tarnasky PR, Knapple WL, Aabakken L, Hoffman BJ, Cunningham JT, Hawes RH, Cotton PB. Evaluation of unexplained acute and acute recurrent pancreatitis using endoscopic retrograde cholangiopancreatography, sphincter of Oddi manometry and endoscopic ultrasound. Endoscopy. 2002;34:617-623.  [PubMed]  [DOI]
11.  Gregor JC, Ponich TP, Detsky AS. Should ERCP be routine after an episode of “idiopathic” pancreatitis? A cost-utility analysis. Gastrointest Endosc. 1996;44:118-123.  [PubMed]  [DOI]
12.  Baillie J. What should be done with idiopathic recurrent pancreatitis that remains ‘idiopathic’ after standard investigation? JOP. 2001;2:401-405.  [PubMed]  [DOI]
13.  Ros E, Navarro S, Bru C, Garcia-Pugés A, Valderrama R. Occult microlithiasis in ‘idiopathic’ acute pancreatitis: prevention of relapses by cholecystectomy or ursodeoxycholic acid therapy. Gastroenterology. 1991;101:1701-1709.  [PubMed]  [DOI]
14.  Levy MJ. The hunt for microlithiasis in idiopathic acute recurrent pancreatitis: should we abandon the search or intensify our efforts? Gastrointest Endosc. 2002;55:286-293.  [PubMed]  [DOI]
15.  Neoptolemos JP, Davidson BR, Winder AF, Vallance D. Role of duodenal bile crystal analysis in the investigation of ‘idiopathic’ pancreatitis. Br J Surg. 1988;75:450-453.  [PubMed]  [DOI]
16.  Moskovitz M, Min TC, Gavaler JS. The microscopic examination of bile in patients with biliary pain and negative imaging tests. Am J Gastroenterol. 1986;81:329-333.  [PubMed]  [DOI]
17.  Reyes López A, Miño Fugarolas G, Costán Rodero G, Pérez Rodríguez E, Montero Alvarez JL, Cabrera D. [Value of duodenal drainage in the etiologic diagnosis of acute pancreatitis]. Rev Esp Enferm Dig. 1993;83:363-366.  [PubMed]  [DOI]
18.  Dahan P, Andant C, Lévy P, Amouyal P, Amouyal G, Dumont M, Erlinger S, Sauvanet A, Belghiti J, Zins M. Prospective evaluation of endoscopic ultrasonography and microscopic examination of duodenal bile in the diagnosis of cholecystolithiasis in 45 patients with normal conventional ultrasonography. Gut. 1996;38:277-281.  [PubMed]  [DOI]
19.  Vila JJ, Arín A, Borobio E, Arín B, Irisarri R, Jiménez FJ, Adrian A, Borda F. Prospective double blinded comparison of endosonography versus microscopic bile examination for diagnosing microlithiasis in patients with biliary colic or idiopathic acute pancreatitis. Endoscopy. 2007;39 Suppl 1:A281.  [PubMed]  [DOI]
20.  Norton SA, Alderson D. Endoscopic ultrasonography in the evaluation of idiopathic acute pancreatitis. Br J Surg. 2000;87:1650-1655.  [PubMed]  [DOI]
21.  Frossard JL, Sosa-Valencia L, Amouyal G, Marty O, Hadengue A, Amouyal P. Usefulness of endoscopic ultrasonography in patients with “idiopathic” acute pancreatitis. Am J Med. 2000;109:196-200.  [PubMed]  [DOI]
22.  Liu CL, Lo CM, Chan JK, Poon RT, Fan ST. EUS for detection of occult cholelithiasis in patients with idiopathic pancreatitis. Gastrointest Endosc. 2000;51:28-32.  [PubMed]  [DOI]
23.  Tandon M, Topazian M. Endoscopic ultrasound in idiopathic acute pancreatitis. Am J Gastroenterol. 2001;96:705-709.  [PubMed]  [DOI]
24.  Coyle WJ, Pineau BC, Tarnasky PR, Knapple WL, Aabakken L, Hoffman BJ, Cunningham JT, Hawes RH, Cotton PB. Evaluation of unexplained acute and acute recurrent pancreatitis using endoscopic retrograde cholangiopancreatography, sphincter of Oddi manometry and endoscopic ultrasound. Endoscopy. 2002;34:617-623.  [PubMed]  [DOI]
25.  Yusoff IF, Raymond G, Sahai AV. A prospective comparison of the yield of EUS in primary vs. recurrent idiopathic acute pancreatitis. Gastrointest Endosc. 2004;60:673.  [PubMed]  [DOI]
26.  Garg PK, Tandon RK, Madan K. Is biliary microlithiasis a significant cause of idiopathic recurrent acute pancreatitis? A long-term follow-up study. Clin Gastroenterol Hepatol. 2007;5:75-79.  [PubMed]  [DOI]
27.  Vila JJ, Vicuña M, Irisarri R, de la Higuera BG, Ruiz-Clavijo D, Rodríguez-Gutiérrez C, Urman JM, Bolado F, Jiménez FJ, Arín A. Diagnostic yield and reliability of endoscopic ultrasonography in patients with idiopathic acute pancreatitis. Scand J Gastroenterol. 2010;45:375-381.  [PubMed]  [DOI]
28.  Bournet B, Migueres I, Delacroix M, Vigouroux D, Bornet JL, Escourrou J, Buscail L. Early morbidity of endoscopic ultrasound: 13 years’ experience at a referral center. Endoscopy. 2006;38:349-354.  [PubMed]  [DOI]
29.  Mirbagheri SA, Mohamadnejad M, Nasiri J, Vahid AA, Ghadimi R, Malekzadeh R. Prospective evaluation of endoscopic ultrasonography in the diagnosis of biliary microlithiasis in patients with normal transabdominal ultrasonography. J Gastrointest Surg. 2005;9:961-964.  [PubMed]  [DOI]
30.  Irisawa A, Katakura K, Ohira H, Sato A, Bhutani MS, Hernandez LV, Koizumi M. Usefulness of endoscopic ultrasound to diagnose the severity of chronic pancreatitis. J Gastroenterol. 2007;42 Suppl 17:90-94.  [PubMed]  [DOI]
31.  Sahai AV, Zimmerman M, Aabakken L, Tarnasky PR, Cunningham JT, van Velse A, Hawes RH, Hoffman BJ. Prospective assessment of the ability of endoscopic ultrasound to diagnose, exclude, or establish the severity of chronic pancreatitis found by endoscopic retrograde cholangiopancreatography. Gastrointest Endosc. 1998;48:18-25.  [PubMed]  [DOI]
32.  Wallace MB, Hawes RH, Durkalski V, Chak A, Mallery S, Catalano MF, Wiersema MJ, Bhutani MS, Ciaccia D, Kochman ML. The reliability of EUS for the diagnosis of chronic pancreatitis: interobserver agreement among experienced endosonographers. Gastrointest Endosc. 2001;53:294-299.  [PubMed]  [DOI]
33.  DeWitt J, Devereaux B, Chriswell M, McGreevy K, Howard T, Imperiale TF, Ciaccia D, Lane KA, Maglinte D, Kopecky K. Comparison of endoscopic ultrasonography and multidetector computed tomography for detecting and staging pancreatic cancer. Ann Intern Med. 2004;141:753-763.  [PubMed]  [DOI]
34.  Ho S, Bonasera RJ, Pollack BJ, Grendell J, Feuerman M, Gress F. A single-center experience of endoscopic ultrasonography for enlarged pancreas on computed tomography. Clin Gastroenterol Hepatol. 2006;4:98-103.  [PubMed]  [DOI]
35.  Klapman JB, Chang KJ, Lee JG, Nguyen P. Negative predictive value of endoscopic ultrasound in a large series of patients with a clinical suspicion of pancreatic cancer. Am J Gastroenterol. 2005;100:2658-2661.  [PubMed]  [DOI]
36.  Soriano A, Castells A, Ayuso C, Ayuso JR, de Caralt MT, Ginès MA, Real MI, Gilabert R, Quintó L, Trilla A. Preoperative staging and tumor resectability assessment of pancreatic cancer: prospective study comparing endoscopic ultrasonography, helical computed tomography, magnetic resonance imaging, and angiography. Am J Gastroenterol. 2004;99:492-501.  [PubMed]  [DOI]
37.  Chen VK, Arguedas MR, Kilgore ML, Eloubeidi MA. A cost-minimization analysis of alternative strategies in diagnosing pancreatic cancer. Am J Gastroenterol. 2004;99:2223-2234.  [PubMed]  [DOI]
38.  Murakami Y, Uemura K, Ohge H, Hayashidani Y, Sudo T, Sueda T. Intraductal papillary-mucinous neoplasms and mucinous cystic neoplasms of the pancreas differentiated by ovarian-type stroma. Surgery. 2006;140:448-453.  [PubMed]  [DOI]
39.  Aithal GP, Chen RY, Cunningham JT, Durkalski V, Kim EY, Patel RS, Wallace MB, Hawes RH, Hoffman BJ. Accuracy of EUS for detection of intraductal papillary mucinous tumor of the pancreas. Gastrointest Endosc. 2002;56:701-707.  [PubMed]  [DOI]
40.  Ahmad NA, Kochman ML, Lewis JD, Ginsberg GG. Can EUS alone differentiate between malignant and benign cystic lesions of the pancreas? Am J Gastroenterol. 2001;96:3295-3300.  [PubMed]  [DOI]
41.  Frossard JL, Amouyal P, Amouyal G, Palazzo L, Amaris J, Soldan M, Giostra E, Spahr L, Hadengue A, Fabre M. Performance of endosonography-guided fine needle aspiration and biopsy in the diagnosis of pancreatic cystic lesions. Am J Gastroenterol. 2003;98:1516-1524.  [PubMed]  [DOI]
42.  Jacobson BC, Baron TH, Adler DG, Davila RE, Egan J, Hirota WK, Leighton JA, Qureshi W, Rajan E, Zuckerman MJ. ASGE guideline: The role of endoscopy in the diagnosis and the management of cystic lesions and inflammatory fluid collections of the pancreas. Gastrointest Endosc. 2005;61:363-370.  [PubMed]  [DOI]
43.  Artifon EL, Kumar A, Eloubeidi MA, Chu A, Halwan B, Sakai P, Bhutani MS. Prospective randomized trial of EUS versus ERCP-guided common bile duct stone removal: an interim report (with video). Gastrointest Endosc. 2009;69:238-243.  [PubMed]  [DOI]
44.  Testoni PA, Mariani A, Curioni S, Zanello A, Masci E. MRCP-secretin test-guided management of idiopathic recurrent pancreatitis: long-term outcomes. Gastrointest Endosc. 2008;67:1028-1034.  [PubMed]  [DOI]
45.  Sugiyama M, Haradome H, Atomi Y. Magnetic resonance imaging for diagnosing chronic pancreatitis. J Gastroenterol. 2007;42 Suppl 17:108-112.  [PubMed]  [DOI]
46.  Delhaye M, Matos C, Arvanitakis M, Deviere J. Pancreatic ductal system obstruction and acute recurrent pancreatitis. World J Gastroenterol. 2008;14:1027-1033.  [PubMed]  [DOI]
47.  Kondo S, Isayama H, Akahane M, Toda N, Sasahira N, Nakai Y, Yamamoto N, Hirano K, Komatsu Y, Tada M. Detection of common bile duct stones: comparison between endoscopic ultrasonography, magnetic resonance cholangiography, and helical-computed-tomographic cholangiography. Eur J Radiol. 2005;54:271-275.  [PubMed]  [DOI]
48.  Verma D, Kapadia A, Eisen GM, Adler DG. EUS vs MRCP for detection of choledocholithiasis. Gastrointest Endosc. 2006;64:248-254.  [PubMed]  [DOI]
49.  Chen RY, Hawes RH. Idopathic acute pancreatitis: Is EUS worth doing? Am J Gastroenterol. 2002;97:1244-1246.  [PubMed]  [DOI]
50.  Seewald S, Omar S, Soehendra N. Acute pancreatitis: the acute attack. Acute recurrent pancreatitis. Endoscopy. 2006;38 Suppl 1:S21-S22.  [PubMed]  [DOI]
51.  Al-Haddad M, Wallace MB. Diagnostic approach to patients with acute idiopathic and recurrent pancreatitis, what should be done? World J Gastroenterol. 2008;14:1007-1010.  [PubMed]  [DOI]