[Real-time sonography of cholangiolithiasis. Dependence of the diagnostic accuracy on the competence of the operator].

The reliability of sonography for demonstrating bile duct stones depends on technical factors and on the experience of the operator. The pick up rate of an experienced operator has been compared with that of three other doctors who had performed sonography only briefly and intermittently. This was based on the results of surgery in 142 patients. The sensitivity of the experienced operator was 72.4% and almost twice that of the other doctors, who showed an accuracy of 37.5 and 44%. The competence of the operator depends not only on adequate training, but also on continuous practice.