Magnetic resonance cholangiography: past, present and future: a review.

INTRODUCTION Magnetic resonance cholangio-pancreatography (MRCP) is a valuable method for the evaluation of biliary and pancreatic diseases and a valuable alternative to endoscopic retrograde cholangiopancreatography (ERCP). It is noninvasive and does not require the use of contrast material or ionizing radiation. Since its introduction in 1991, this technique has significantly improved in spatial resolution, now allowing the accurate assessment of the major bilio-pancreatic diseases. STATE OF THE ART MRCP is commonly performed with heavily T2-weighted sequences in order to highlight static fluids, as those contained in dilated pancreatic and biliary ducts. Newest MR equipments allow to perform MRCP within 10-15 minutes, due to the availability of ultra-fast sequences. Currently, MRCP is widely performed as a primary imaging modality for the assessment of obstructive jaundice and other benign or malignant bilio-pancreatic ducts abnormalities. The primary MRCP application is the evaluation of biliary obstructions due to choledocholithiasis, iatrogenic strictures, cholangiocarcinoma or pancreatic carcinoma. Other MRCP applications include the assessment of the exocrine pancreatic function, following secretin stimulation. Whenever needed, the MRCP may be completed with a conventional contrast-enhanced magnetic resonance imaging (MRI) of the upper abdomen and functional studies as well, thus providing an all-in-one mophological and functional study of the pancreas and biliary system. More recent applications include the possibility of 3D reconstructions and the use of hepato-biliary contrast agents, that provide a higher definition of the biliary tree, both in pathologic and normal conditions. The introduction of 3Tesla magnets could provide higher anatomic detail. CONCLUSIONS In the next years the role of MRCP will further expand, due to the availability of faster sequences, 3D imaging and functional studies.