[The value of various imaging technics in the preoperative diagnosis of choledocholithiasis].

In a retrospective study different methods of detecting choledocholithiasis-sonography, intravenous cholangiography, computed tomography and transhepatic cholangiography-have been compared to evaluate their accuracy. A total of 130 investigations in 93 patients were analysed. Choledocholithiasis could be predicted by sonography in 42.9%, by intravenous cholangiography in 60% and by transhepatic cholangiography in 85.7%. The overall accuracy rate with a single investigation was 51.6%. The combination of different methods increased the accuracy rate of 81.6%. We use sonography as the screening examination. In unclear cases transhepatic cholangiography has proven helpful in demonstrating choledocholithiasis. Only cholangiography, together with cholangioscopy, is performed intraoperatively. Due to high cost and limited availability, computed tomography should not be used as a basic examination.