الفهرس 
The LiverOnly 14 pages are availabe for public view
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Abstract
Biliary complications after liver transplanation remain a serious clinical problem that result in increased morbidity, liver dysfunction, and graft loss. Biliary complications are one of the leading causes of liver failure and occur in 10–30% of patients who undergo transplantation. In addition, clinical and biologic signs are nonspecific, and imaging techniques are generally required to establish the diagnosis.
Direct cholangiographic techniques such as ERCP or percutaneous transhepatic cholangiography (PTHC) are invasive and carry a relatively high rate of procedure-related complications; therefore it should not be considered a diagnostic tool but rather a therapeutic technique that can be performed at the time of the diagnostic procedure.
Recently, MRI and MR cholangiopancreatography (MRCP) and has significantly changed our approach to diagnosis and management of biliary complications after liver transplantation because it allows noninvasive visualization of the biliary tree with exquisite anatomic details.
agnetic resonance cholangiopancratography (MRCP) is a radiologic technique that produces images of the pancreatico-biliary tree that are similar in appearance to those obtained by invasive radiographic methods, such as endoscopic retrograde cholangio-pancreatography (ERCP).
MRCP takes advantage of the inherent contrast-related properties of fluid in the biliary and pancreatic ducts. Because MRCP does not require the administration of any exogenous contrast materials, it is an ideal imaging method for patients with allergies to iodine-based contrast materials or those with a general history of atopy.
The interest in MRCP on the part of surgeons, gastroenterologists, and radiologists is due to its accuracy, its safety, and its availability with nearly all modern magnetic resonance scanners, as well as to the fact that it is well tolerated by patients.
MRCP is a passive procedure that displays the ducts in the resting state and hence more accurately displays the native caliber of the duct than ERCP. In ERCP, segments of a duct may be overdistended because of an attempt to visualize the duct upstream from a stricture, or segments may be underdistended because of the operator’s fear of inducing cholangitis or pancreatitis.
MRCP accurately diagnoses biliary complications, such as biliary obstruction, biliary strictures types, extent and length. Also MRCP allows accurate diagnosis of biliary sludge, stones, bile leak, biloma, abscesses and cholangitis. MRCP with very high degree of sensitivity and specifity (up to 96-100 % of patients).
The main limitations of MRCP are the lack of availability of magnetic resonance equipment, the fact that the procedure can cause claustrophobia and noise trouble, and (as compared with conventional radiographic cholangiography) the inferior spatial resolution of the images. Initial difficulties relating to metallic-clip artifacts, respiratory motion, the length of the procedure, and the lack of physiologic information have largely been overcomed.
So in conclusion, MRCP has become a competitive replacement for invasive imaging techniques, such as ERCP, in a wide variety of biliary applications (especially after liver transplantation). The lower cost, absence of ionizing radiation, and greater safety for patients make MRCP an attractive diagnostic method. The main role of MRCP should be to reserve the use of invasive techniques for patients in whom a therapeutic procedure is necessary.