MR CHOLANGIOPANCREATOGRAPHY - POTENTIAL CLINICAL-APPLICATIONS

Magnetic resonance cholangiopancreatography (MRCP), when performed wit h heavily T2-weighted fast spin-echo sequences and a phased-array tors o coil, provides high-resolution images of the biliary tree and pancre atic duct in multiple planes of section. Use of maximum-intensity proj ection (MIP) reformations is helpful when overall three-dimensional vi ews are needed (eg, in cases of cholangiocarcinoma), but the source im age must be carefully compared with the MIP reformation to avoid missi ng potential filling defects and other important details obscured by t he reformation. Preliminary work indicates that the accuracy of MRCP i s comparable to that of endoscopic retrograde cholangiopancreatography in diagnosing the cause of bile duct obstruction, At MRCP, bile duct stones appear as hypointense foci within high-signal-intensity ducts, and stones as small as 2 mm in diameter can be seen, In cases of chola ngiocarcinoma, the main advantage of MRCP is that it can noninvasively provide a three-dimensional overview of the biliary tree, which can h elp in planning treatment, However, the limited spatial resolution of MRCP curtails its role in the characterization of bile duct stenosis, visualization of small intraampullary tumors, and diagnosis of chronic pancreatitis, MRCP is an important adjunct to traditional pulse seque nces in the work-up of pancreatic and biliary diseases.