[Results of sonographic diagnosis of choledochal calculi]

To evaluate sonographic accuracy in the diagnosis of choledochal calculi 44 patients were examined prospectively with a mechanical sector scanner before endoscopic retrograde cholangiography (ERC). Calculi with a diameter of more than 1.5 cm could be detected in all cases. Smaller stones (less than 1 cm) were missed in 50% of cases. To quantitate sensitivity in daily clinical practice, the data of 229 patients, suspected to have common bile duct stones, were analysed retrospectively. The overall accuracy was 76%, 90% when an experienced sonographer performed the examination and 47% if the examiner was less experienced. From these data it is concluded that the sonographic detection of choledochal calculi is influenced by the examination technique, experience of the examiner and diameter of the stones.