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Magnetic resonance cholangiopancreatography
Invited Review Pancreatology 2002;2:499–502 DOI: 10.1159/000066091
Magnetic Resonance Cholangiopancreatography The Fine Art of Bilio-Pancreatic Imaging
H.E. Adamek a H. Breer b G. Layer b J.F. Riemann a Deptartments of a Medicine and b Radiology, Klinikum Ludwigshafen, Academic Hospital of the Johannes Gutenberg University of Mainz, Ludwigshafen, Germany
Key Words Magnetic resonance cholangiopancreatography W Magnetic resonance imaging W Hepatobiliary diseases W Pancreatic diseases W Diagnostic algorithms
Abstract 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. Copyright © 2002 S. Karger AG, Basel and IAP
Introduction
Cholangiopancreatography used to mean swallowing an uncomfortable endoscope, get some contrast through a catheter that puts you at risk of pancreatitis and leaves you behind with a sore throat. Not any more! The keyword is magnetic resonance imaging (MRI). MRI has been called the most important development in medical diagnosis since the discovery of the X-ray more than 100 years ago. It
ABC
© 2002 S. Karger AG, Basel and IAP 1424–3903/02/0026–0499$18.50/0
Fax + 41 61 306 12 34 E-Mail [email protected] www.karger.com
Accessible online at: www.karger.com/pan
has early become the major diagnostic tool in neuroradiology and is now being applied to virtually every part of the body. With the development of fast imaging sequences and special coils, the improvement in the quality of abdominal MRI has come a long way in a short time. Those who use it are virtually certain they know the best way of taking pictures from nearly every part of the human body. MRI is a perfect combination of ambitious technique, patient comfort and beautiful pictures and its effectiveness has been expanded to a variety of gastrointestinal disorders. The gastroenterologist’s attention is currently focussed on biliopancreatic diseases, since dynamic imaging, evaluation of pancreatic function and excellent diagnostic yield even in rare pathologies of pancreas renders magnetic resonance cholangiopancreatography (MRCP) an indispensable diagnostic tool in modern gastroenterology. It was inevitable that MRI technologies are now not longer limited to radiologists alone, since careful development of such sophisticated a method is only possible with a joint account. Different medical specialties put their talents in the service of technical developments and the demands of the patients. The experience accumulated over the last 10 years in the evaluation of MRCP is described in this review.
Pancreatic-Biliary Diseases
The ability of MRI to depict a dilated biliary tract was first demonstrated in 1986 [1]. Five years later, MRCP
H.E. Adamek, MD Med. Klinik C, Klinikum Ludwigshafen Bremserstrasse 79 D–67063 Ludwigshafen (Germany) Fax +49 621 5034112, E-Mail [email protected]
Fig. 1. Common bile duct stone. MRCP shows a dilatation of the
common bile duct and a small signal void within the duct just proximal to the ampulla.
was described for the first time as a completely noninvasive application which enables visualization of the biliary and pancreatic ducts similar to those of ERCP without the need for contrast material [2]. Recent technical advances have led to notable improvements in this field with a good toleration by patients and a surprising clinical acceptance by gastroenterologists.
Biliary Diseases
MRCP was found to be highly sensitive (90–100%) in the visualization of the normal common bile duct. Furthermore, bile duct dilatation is constantly visible during MRCP [3]. In the diagnosis of choledocholithiasis, MRCP reaches a sensitivity between 80 and 100% when modern techniques with strong gradients are employed (fig. 1). The sensitivity of MRCP for the detection of choledocholithiasis is superior to that of percutaneous ultrasonography and computed tomography [4]. There are limitations for routine MRC use with standard equipment for diagnosing common bile duct stones, particularly for stones smaller than 6 mm [5]. Another potential error is the misdiagnosis of a stone as another type of intraluminal filling defect, such as an intraductal tumor, blood clot, or gas bubble.
500
Pancreatology 2002;2:499–502
Fig. 2. Pancreatic carcinoma. MRCP shows dilatation of biliary and pancreatic ducts above high grade stenosis at level of head of pancreas (‘double-duct sign’).
Congenital biliary abnormalities are well depicted by MRCP. Extra- and intrahepatic dilatation is adequately revealed in patients with choledochal cysts [6]. In hepatolithiasis and for the diagnosis of primary sclerosing cholangitis, MRCP also proved to be useful [7, 8]. There is currently no consensus on the precise role of MRCP in the clinical assessment of patients with suspected bile duct obstruction. Although the presence and site of biliary strictures can be identified by percutaneous ultrasonography, the evaluation of the cause of such strictures may be more difficult and requires direct cholangiopancreatography. ERCP often only shows the ducts below the site of obstruction (double duct sign); visualization of an obstructed part of the biliary tree is not always possible. In addition, opacification of undrained bile ducts places the patient at risk of cholangitis. MRCP may detect the presence of biliary obstruction (fig. 2) and its level with a sensitivity of about 90% and a specificity that reaches almost 100% [9]. Furthermore, it routinely identifies the dilated biliary tree upstream of an obstruction, allowing synchronous strictures to be identified [10]. Nevertheless, the cause of such strictures may be more difficult to determine on the basis of MRCP alone. The differential diagnostic considerations can be improved with the use of conventional cross-sectional MR images. Recently,
Adamek/Breer/Layer/Riemann
Fig. 3. Carcinoma on the ampulla of Vater. MRCP demonstrates the
obstruction of the common bile duct at the level of papilla, where the carcinoma was located, with associated dilatation of the proximal biliary tree, and a normal caliber main pancreatic duct.
MRCP was shown to be extremely useful in providing a ‘road map’ in patients with malignant tumors that involve the main hepatic confluence (Klatskin tumors). With pretherapeutic MRCP, it is possible to stratify patients according to the extent of bile duct invasion, without the risk of injecting contrast. The Berlin group evaluated the outcome of MRCP-guided unilateral endoscopic stent placement in 35 patients with advanced hilar tumors. After unilateral stent placement (in the MRC-selected radicle), which was technically successful in all patients, a significant improvement in bilirubin levels and jaundice was observed with an early cholangitis rate of only 6% [11]. These results clearly indicate that in certain conditions, even if therapeutic options are warranted, MRCP may guide further endoscopic strategy by evaluating the best concept prior to intervention and consequently reducing ERCP-related complications. Similar concepts are to be expected in further bilio-pancreatic pathologies in the future. The role of MRCP in patients with an obstruction at the level of the ampulla has not been adequately studied (fig. 3). ERCP has obviously several advantages over MRCP in this group of patients, since it permits direct visualization of the ampulla, biopsy of lesions or intraductal sonography.
Magnetic Resonance Cholangio-Pancreatography
Fig. 4. Intraductal papillary mucinous tumor of the pancreas. MRCP demonstrates a localized dilatation of the pancreatic duct associated with a tortuous and cystic dilatation of the main duct and its branches in the pancreatic head.
Pancreatic Diseases
Due to the small caliber, the evaluation of the normal pancreatic duct has long been a major technical challenge for MRCP. Visualization of the pancreatic duct can be improved if imaging is performed using advanced techniques and after the administration of secretin. The administration of secretin is now recommended when the pancreatic duct is not apparent on MRCP [12]. Secretinenhanced MRCP can also permit visualization of possible communications of the pancreatic duct with pseudocysts in patients with chronic pancreatitis. Some authors even prophesize that dynamic secretin-enhanced MRCP, with the acquisition of multiple pictures at short intervals after stimulation, will improve the understanding of the pathophysiology of pancreatitis [13]. Should the dynamic evaluation of the bile ducts after choleretic stimulation also come into reality, the performance of an ERCP to measure sphincter pressures manometrically is likely to become obsolete. So far, MRCP has seldom been used in the setting of acute pancreatitis. Recent reports [14], however, have reported similar results between contrast-enhanced CT and nonenhanced MR cholangiopancreatography in diagnosing pancreatic necrosis and acute fluid collections.
Pancreatology 2002;2:499–502
501
MRI, however, does not offer the ideal diagnostic surroundings for critically ill patients with a lot of monitoring and therapy equipment. Presently, MRCP has been shown to be of clear value in the diagnosis of chronic pancreatitis [15]. Furthermore, the technique might help to detect early stages of chronic pancreatitis: Comparing sampling of pancreatic fluid with S-MRCP, Cappeliez et al. [16] found that duodenal filling grade determined at MR pancreatography after secretin stimulation allows specific estimation of pancreatic exocrine function. Recently, MR pancreatography was shown to be helpful in the diagnosis and treatment planning of pancreaticopleural fistula as a rare complication of inflammatory pancreatic disease [17]. In the diagnosis of pancreas divisum and cystic, mucin producing tumors of the pancreas (fig. 4), MRCP has been reported to be equal or even superior to ERCP [18, 19]. Presently, it is feasible to presume that the use of MRCP may prevent inappropriate explorations of the pancreatic and common bile ducts in cases of suspected pancreatic carcinoma, where interventional endoscopic therapy is unlikely [20]. Undoubtedly,
MRCP is the method of choice in all patients with technically failed ERCP examinations [21] or with postoperative pancreaticobiliary changes [22].
Outlook
Whether or not the survival of diagnostic endoscopy is under debate, MRI could mark a historic turning point in gastroenterology. Conceivably, MRCP and MRI together with magnetic resonance angiography (MRA) may prove most cost-effective in current preoperative staging practices for bile duct and pancreatic cancer with greater patient acceptance. The speed of the technique’s spread during the last years frightened gastroenterologists [23], but it also galvanized a lot of them into action. We should not fear MR as potential competition for endoscopy, but should consider magnetic resonance imaging to be a revolutionary development in gastrointestinal diagnostics, one that requires a close cooperation and should be included into current algorithms.
References 1 Hennig J, Nauerth A, Friedburg H: A fast imaging method for clinical MR. Magn Reson Med 1986;3:823–833. 2 Wallner BK, Schumacher KA, Weidenmaier W, et al: Dilated biliary tract: Evaluation with MR cholangiography with a T2-weighted contrast enhanced fast sequence. Radiology 1991; 181:805–808. 3 Soto JA, Barish MA, Yucel EK, et al: Magnetic resonance cholangiography: Comparison with endoscopic retrograde cholangiopancreatography. Gastroenterology 1996;110:589–597. 4 Pasanen P, Partanen K, Pikkarainen P, et al: Ultrasonography, CT and ERCP in the diagnosis of choledochal stones. Acta Radiol 1992;33: 53–56. 5 Zidi SH, Prat F, Le Guen O, et al: Use of magnetic resonance cholangiography in the diagnosis of choledocholithiasis: Prospective comparison with a reference imaging method. Gut 1999;44:118–122. 6 Adamek HE, Schilling D, Weitz M, et al: Choledochocele imaged with magnetic resonance cholangiography. Am J Gastroenterol 2000;95: 1082–1083. 7 Kubo S, Hamba H, Hirohashi K, et al: Magnetic resonance cholangiography in hepatolithiasis. Am J Gastroenterol 1997;92:629–631. 8 Ito K, Mitchell DG, Outwater EK, Blasbalg R: Primary sclerosing cholangitis: MR imaging features. AJR Am J Roentgenol 1999;172: 1527–1533. 9 Adamek HE, Albert J, Weitz M, et al: A prospective evaluation of magnetic resonance cholangiopancreatography in patients with suspected bile duct obstruction. Gut 1998;43:680–683.
502
10 Hintze RE, Adler A, Veltzke W, et al: Clinical significance of magnetic resonance cholangiopancreatography (MRCP) compared with ERCP. Endoscopy 1997;29:182–187. 11 Hintze RE, Abou-Rebyeh H, Adler A, VeltzkeSchlieker W, Felix R, Wiedenmann B: Magnetic resonance cholangiopancreatography-guided unilateral endoscopic stent placement for Klatskin tumors. Gastrointest Endosc 2001;53:40– 46. 12 Manfredi R, Costamagna G, Brizi MG, et al: Severe chronic pancreatitis versus suspected pancreatic disease: Dynamic MR cholangiopancreatography after secretin stimulation. Radiology 2000;214:849–855. 13 Matos C, Metens T, Devière J, et al: Pancreatic duct: Morphologic and functional evaluation with dynamic MR pancreatography after secretin stimulation. Radiology 1997;203:435–441. 14 Lecesne R, Taourel P, Bret PM, et al: Acute pancreatitis: Interobserver agreement and correlation of CT and MR cholangiopancreatography with outcome. Radiology 1999;211:727– 735. 15 Sica GT, Braver J, Cooney MJ, et al: Comparison of endoscopic retrograde cholangiopancreatography with MR cholangiopancreatography in patients with pancreatitis. Radiology 1999;210:605–610. 16 Cappeliez O, Delhaye M, Devière J, Le Moine O, Metens T, Nicaise N, Cremer M, Stryuven J, Matos C: Chronic pancreatitis: Evaluation of pancreatic exocrine function with MR pancreatography after secretin stimulation. Radiology 2000;215:358–364.
Pancreatology 2002;2:499–502
17 Mori Y, Iwai A, Inagaki T, et al: Pancreaticopleural fistula imaged with magnetic resonance pancreatography. Pancreatology 2001;1:369– 370. 18 Albert J, Schilling D, Breer H, Jungius KP, Riemann JF, Adamek HE: Mucinous cystadenomas and intraductal papillary mucinous tumors of the pancreas in magnetic resonance cholangiopancreatography. Endoscopy 2000; 32:472–476. 19 Silas AM, Morrin MM, Ratopoulos V, Keogan MT: Intraductal papillary mucinous tumors of the pancreas. AJR Am J Roentgenol 2001;176: 179–185. 20 Adamek HE, Albert J, Breer H, Weitz M, Schilling D, Riemann JF: Pancreatic cancer detection with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography: A prospective controlled study. Lancet 2000;356:190–193. 21 Adamek HE, Weitz M, Breer H, et al: Value of magnetic resonance cholangiopancreatography (MRCP) after unsuccessful ERCP. Endoscopy 1997;29:741–744. 22 Tang Y, Yamashita Y, Arakawa A: Pancreaticobiliary ductal system: Value of half-Fourier acquisition with relaxation enhancement MR cholangiopancreatography for postoperative evaluation. Radiology 2000;215:81–88. 23 Adamek HE, Breer H, Karschkes T, Albert J, Schilling D, Riemann JF: Magnetic resonance imaging in gastroenterology: Time to say goodbye to all that endoscopy? Endoscopy 2000;32: 406–410.
Adamek/Breer/Layer/Riemann
Magnetic Resonance Cholangiopancreatography The Fine Art of Bilio-Pancreatic Imaging
H.E. Adamek a H. Breer b G. Layer b J.F. Riemann a Deptartments of a Medicine and b Radiology, Klinikum Ludwigshafen, Academic Hospital of the Johannes Gutenberg University of Mainz, Ludwigshafen, Germany
Key Words Magnetic resonance cholangiopancreatography W Magnetic resonance imaging W Hepatobiliary diseases W Pancreatic diseases W Diagnostic algorithms
Abstract 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. Copyright © 2002 S. Karger AG, Basel and IAP
Introduction
Cholangiopancreatography used to mean swallowing an uncomfortable endoscope, get some contrast through a catheter that puts you at risk of pancreatitis and leaves you behind with a sore throat. Not any more! The keyword is magnetic resonance imaging (MRI). MRI has been called the most important development in medical diagnosis since the discovery of the X-ray more than 100 years ago. It
ABC
© 2002 S. Karger AG, Basel and IAP 1424–3903/02/0026–0499$18.50/0
Fax + 41 61 306 12 34 E-Mail [email protected] www.karger.com
Accessible online at: www.karger.com/pan
has early become the major diagnostic tool in neuroradiology and is now being applied to virtually every part of the body. With the development of fast imaging sequences and special coils, the improvement in the quality of abdominal MRI has come a long way in a short time. Those who use it are virtually certain they know the best way of taking pictures from nearly every part of the human body. MRI is a perfect combination of ambitious technique, patient comfort and beautiful pictures and its effectiveness has been expanded to a variety of gastrointestinal disorders. The gastroenterologist’s attention is currently focussed on biliopancreatic diseases, since dynamic imaging, evaluation of pancreatic function and excellent diagnostic yield even in rare pathologies of pancreas renders magnetic resonance cholangiopancreatography (MRCP) an indispensable diagnostic tool in modern gastroenterology. It was inevitable that MRI technologies are now not longer limited to radiologists alone, since careful development of such sophisticated a method is only possible with a joint account. Different medical specialties put their talents in the service of technical developments and the demands of the patients. The experience accumulated over the last 10 years in the evaluation of MRCP is described in this review.
Pancreatic-Biliary Diseases
The ability of MRI to depict a dilated biliary tract was first demonstrated in 1986 [1]. Five years later, MRCP
H.E. Adamek, MD Med. Klinik C, Klinikum Ludwigshafen Bremserstrasse 79 D–67063 Ludwigshafen (Germany) Fax +49 621 5034112, E-Mail [email protected]
Fig. 1. Common bile duct stone. MRCP shows a dilatation of the
common bile duct and a small signal void within the duct just proximal to the ampulla.
was described for the first time as a completely noninvasive application which enables visualization of the biliary and pancreatic ducts similar to those of ERCP without the need for contrast material [2]. Recent technical advances have led to notable improvements in this field with a good toleration by patients and a surprising clinical acceptance by gastroenterologists.
Biliary Diseases
MRCP was found to be highly sensitive (90–100%) in the visualization of the normal common bile duct. Furthermore, bile duct dilatation is constantly visible during MRCP [3]. In the diagnosis of choledocholithiasis, MRCP reaches a sensitivity between 80 and 100% when modern techniques with strong gradients are employed (fig. 1). The sensitivity of MRCP for the detection of choledocholithiasis is superior to that of percutaneous ultrasonography and computed tomography [4]. There are limitations for routine MRC use with standard equipment for diagnosing common bile duct stones, particularly for stones smaller than 6 mm [5]. Another potential error is the misdiagnosis of a stone as another type of intraluminal filling defect, such as an intraductal tumor, blood clot, or gas bubble.
500
Pancreatology 2002;2:499–502
Fig. 2. Pancreatic carcinoma. MRCP shows dilatation of biliary and pancreatic ducts above high grade stenosis at level of head of pancreas (‘double-duct sign’).
Congenital biliary abnormalities are well depicted by MRCP. Extra- and intrahepatic dilatation is adequately revealed in patients with choledochal cysts [6]. In hepatolithiasis and for the diagnosis of primary sclerosing cholangitis, MRCP also proved to be useful [7, 8]. There is currently no consensus on the precise role of MRCP in the clinical assessment of patients with suspected bile duct obstruction. Although the presence and site of biliary strictures can be identified by percutaneous ultrasonography, the evaluation of the cause of such strictures may be more difficult and requires direct cholangiopancreatography. ERCP often only shows the ducts below the site of obstruction (double duct sign); visualization of an obstructed part of the biliary tree is not always possible. In addition, opacification of undrained bile ducts places the patient at risk of cholangitis. MRCP may detect the presence of biliary obstruction (fig. 2) and its level with a sensitivity of about 90% and a specificity that reaches almost 100% [9]. Furthermore, it routinely identifies the dilated biliary tree upstream of an obstruction, allowing synchronous strictures to be identified [10]. Nevertheless, the cause of such strictures may be more difficult to determine on the basis of MRCP alone. The differential diagnostic considerations can be improved with the use of conventional cross-sectional MR images. Recently,
Adamek/Breer/Layer/Riemann
Fig. 3. Carcinoma on the ampulla of Vater. MRCP demonstrates the
obstruction of the common bile duct at the level of papilla, where the carcinoma was located, with associated dilatation of the proximal biliary tree, and a normal caliber main pancreatic duct.
MRCP was shown to be extremely useful in providing a ‘road map’ in patients with malignant tumors that involve the main hepatic confluence (Klatskin tumors). With pretherapeutic MRCP, it is possible to stratify patients according to the extent of bile duct invasion, without the risk of injecting contrast. The Berlin group evaluated the outcome of MRCP-guided unilateral endoscopic stent placement in 35 patients with advanced hilar tumors. After unilateral stent placement (in the MRC-selected radicle), which was technically successful in all patients, a significant improvement in bilirubin levels and jaundice was observed with an early cholangitis rate of only 6% [11]. These results clearly indicate that in certain conditions, even if therapeutic options are warranted, MRCP may guide further endoscopic strategy by evaluating the best concept prior to intervention and consequently reducing ERCP-related complications. Similar concepts are to be expected in further bilio-pancreatic pathologies in the future. The role of MRCP in patients with an obstruction at the level of the ampulla has not been adequately studied (fig. 3). ERCP has obviously several advantages over MRCP in this group of patients, since it permits direct visualization of the ampulla, biopsy of lesions or intraductal sonography.
Magnetic Resonance Cholangio-Pancreatography
Fig. 4. Intraductal papillary mucinous tumor of the pancreas. MRCP demonstrates a localized dilatation of the pancreatic duct associated with a tortuous and cystic dilatation of the main duct and its branches in the pancreatic head.
Pancreatic Diseases
Due to the small caliber, the evaluation of the normal pancreatic duct has long been a major technical challenge for MRCP. Visualization of the pancreatic duct can be improved if imaging is performed using advanced techniques and after the administration of secretin. The administration of secretin is now recommended when the pancreatic duct is not apparent on MRCP [12]. Secretinenhanced MRCP can also permit visualization of possible communications of the pancreatic duct with pseudocysts in patients with chronic pancreatitis. Some authors even prophesize that dynamic secretin-enhanced MRCP, with the acquisition of multiple pictures at short intervals after stimulation, will improve the understanding of the pathophysiology of pancreatitis [13]. Should the dynamic evaluation of the bile ducts after choleretic stimulation also come into reality, the performance of an ERCP to measure sphincter pressures manometrically is likely to become obsolete. So far, MRCP has seldom been used in the setting of acute pancreatitis. Recent reports [14], however, have reported similar results between contrast-enhanced CT and nonenhanced MR cholangiopancreatography in diagnosing pancreatic necrosis and acute fluid collections.
Pancreatology 2002;2:499–502
501
MRI, however, does not offer the ideal diagnostic surroundings for critically ill patients with a lot of monitoring and therapy equipment. Presently, MRCP has been shown to be of clear value in the diagnosis of chronic pancreatitis [15]. Furthermore, the technique might help to detect early stages of chronic pancreatitis: Comparing sampling of pancreatic fluid with S-MRCP, Cappeliez et al. [16] found that duodenal filling grade determined at MR pancreatography after secretin stimulation allows specific estimation of pancreatic exocrine function. Recently, MR pancreatography was shown to be helpful in the diagnosis and treatment planning of pancreaticopleural fistula as a rare complication of inflammatory pancreatic disease [17]. In the diagnosis of pancreas divisum and cystic, mucin producing tumors of the pancreas (fig. 4), MRCP has been reported to be equal or even superior to ERCP [18, 19]. Presently, it is feasible to presume that the use of MRCP may prevent inappropriate explorations of the pancreatic and common bile ducts in cases of suspected pancreatic carcinoma, where interventional endoscopic therapy is unlikely [20]. Undoubtedly,
MRCP is the method of choice in all patients with technically failed ERCP examinations [21] or with postoperative pancreaticobiliary changes [22].
Outlook
Whether or not the survival of diagnostic endoscopy is under debate, MRI could mark a historic turning point in gastroenterology. Conceivably, MRCP and MRI together with magnetic resonance angiography (MRA) may prove most cost-effective in current preoperative staging practices for bile duct and pancreatic cancer with greater patient acceptance. The speed of the technique’s spread during the last years frightened gastroenterologists [23], but it also galvanized a lot of them into action. We should not fear MR as potential competition for endoscopy, but should consider magnetic resonance imaging to be a revolutionary development in gastrointestinal diagnostics, one that requires a close cooperation and should be included into current algorithms.
References 1 Hennig J, Nauerth A, Friedburg H: A fast imaging method for clinical MR. Magn Reson Med 1986;3:823–833. 2 Wallner BK, Schumacher KA, Weidenmaier W, et al: Dilated biliary tract: Evaluation with MR cholangiography with a T2-weighted contrast enhanced fast sequence. Radiology 1991; 181:805–808. 3 Soto JA, Barish MA, Yucel EK, et al: Magnetic resonance cholangiography: Comparison with endoscopic retrograde cholangiopancreatography. Gastroenterology 1996;110:589–597. 4 Pasanen P, Partanen K, Pikkarainen P, et al: Ultrasonography, CT and ERCP in the diagnosis of choledochal stones. Acta Radiol 1992;33: 53–56. 5 Zidi SH, Prat F, Le Guen O, et al: Use of magnetic resonance cholangiography in the diagnosis of choledocholithiasis: Prospective comparison with a reference imaging method. Gut 1999;44:118–122. 6 Adamek HE, Schilling D, Weitz M, et al: Choledochocele imaged with magnetic resonance cholangiography. Am J Gastroenterol 2000;95: 1082–1083. 7 Kubo S, Hamba H, Hirohashi K, et al: Magnetic resonance cholangiography in hepatolithiasis. Am J Gastroenterol 1997;92:629–631. 8 Ito K, Mitchell DG, Outwater EK, Blasbalg R: Primary sclerosing cholangitis: MR imaging features. AJR Am J Roentgenol 1999;172: 1527–1533. 9 Adamek HE, Albert J, Weitz M, et al: A prospective evaluation of magnetic resonance cholangiopancreatography in patients with suspected bile duct obstruction. Gut 1998;43:680–683.
502
10 Hintze RE, Adler A, Veltzke W, et al: Clinical significance of magnetic resonance cholangiopancreatography (MRCP) compared with ERCP. Endoscopy 1997;29:182–187. 11 Hintze RE, Abou-Rebyeh H, Adler A, VeltzkeSchlieker W, Felix R, Wiedenmann B: Magnetic resonance cholangiopancreatography-guided unilateral endoscopic stent placement for Klatskin tumors. Gastrointest Endosc 2001;53:40– 46. 12 Manfredi R, Costamagna G, Brizi MG, et al: Severe chronic pancreatitis versus suspected pancreatic disease: Dynamic MR cholangiopancreatography after secretin stimulation. Radiology 2000;214:849–855. 13 Matos C, Metens T, Devière J, et al: Pancreatic duct: Morphologic and functional evaluation with dynamic MR pancreatography after secretin stimulation. Radiology 1997;203:435–441. 14 Lecesne R, Taourel P, Bret PM, et al: Acute pancreatitis: Interobserver agreement and correlation of CT and MR cholangiopancreatography with outcome. Radiology 1999;211:727– 735. 15 Sica GT, Braver J, Cooney MJ, et al: Comparison of endoscopic retrograde cholangiopancreatography with MR cholangiopancreatography in patients with pancreatitis. Radiology 1999;210:605–610. 16 Cappeliez O, Delhaye M, Devière J, Le Moine O, Metens T, Nicaise N, Cremer M, Stryuven J, Matos C: Chronic pancreatitis: Evaluation of pancreatic exocrine function with MR pancreatography after secretin stimulation. Radiology 2000;215:358–364.
Pancreatology 2002;2:499–502
17 Mori Y, Iwai A, Inagaki T, et al: Pancreaticopleural fistula imaged with magnetic resonance pancreatography. Pancreatology 2001;1:369– 370. 18 Albert J, Schilling D, Breer H, Jungius KP, Riemann JF, Adamek HE: Mucinous cystadenomas and intraductal papillary mucinous tumors of the pancreas in magnetic resonance cholangiopancreatography. Endoscopy 2000; 32:472–476. 19 Silas AM, Morrin MM, Ratopoulos V, Keogan MT: Intraductal papillary mucinous tumors of the pancreas. AJR Am J Roentgenol 2001;176: 179–185. 20 Adamek HE, Albert J, Breer H, Weitz M, Schilling D, Riemann JF: Pancreatic cancer detection with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography: A prospective controlled study. Lancet 2000;356:190–193. 21 Adamek HE, Weitz M, Breer H, et al: Value of magnetic resonance cholangiopancreatography (MRCP) after unsuccessful ERCP. Endoscopy 1997;29:741–744. 22 Tang Y, Yamashita Y, Arakawa A: Pancreaticobiliary ductal system: Value of half-Fourier acquisition with relaxation enhancement MR cholangiopancreatography for postoperative evaluation. Radiology 2000;215:81–88. 23 Adamek HE, Breer H, Karschkes T, Albert J, Schilling D, Riemann JF: Magnetic resonance imaging in gastroenterology: Time to say goodbye to all that endoscopy? Endoscopy 2000;32: 406–410.
Adamek/Breer/Layer/Riemann