Efficacy of non-breath-hold magnetic resonance cholangiography at midfieldstrength

The efficacy of non-breath-hold magnetic resonance (MR) cholangiography at mid-held strength (0.5 Tesla) was evaluated for delineating biliary anatomy and the cause and extent of biliary obstruction,We performed 65 MR cholang iograms on a mid-held 0.5 Tesla MR unit and correlated them with contrast c holangiography and/or surgery. MR cholangiography was found to be both sens itive and specific in the detection of biliary obstruction and in the defin ition of its cause (sensitivity 98%, specificity 100%, positive predictive value 100%, negative predictive value 85.7%, accuracy 98%), MR cholangiogra phy accurately predicted the level of obstruction in 94 per cent of strictu res. Normal caliber intra-hepatic biliary radicles were visualised in only 6 per cent of the MR cholangiograms, In contrast, 94 per cent of dilated in trahepatic. biliary radicles were demonstrated. The confluence, and right a nd left hepatic ducts were visualized in 98 per cent; the gall bladder in 6 5 per cent; the cystic duct in 45 per cent and the cystic duct insertion in 25 per cent. The extrahepatic bile duct was seen In 82.7 per cent. A norma l caliber pancreatic duct was seen in 18 per cent while a dilated pancreati c duct was seen in 86 per cent; The pancreatico-biliary junction was visual ised in 7 per cent. Non-breath-hold MR cholangiography at mid-field strengt h is a highly accurate method of evaluating the cause and level of biliary obstruction, comparable to high-field MR cholangiography, The spatial resol ution however is inadequate for the detection of variations in biliary or p ancreatic ductal anatomy when the ducts are of normal caliber.