Intra-operative cholangiography and ultrasonography were compared in s
creening for unsuspected common bile duct stones. In 57 consecutive pa
tients both procedures were performed, and in 60 only ultrasonography
was used. Although the study was conducted during the initial self-tea
ching period (regarding ultrasonography) the results show an advantage
of this relatively new diagnostic technique. The false positive rate
was lower and consequently the predictive value of a positive test was
higher for intraoperative ultrasonography. The main benefit would thu
s be a lower rate of negative common bile duct explorations. Our early
results suggest that the general surgeon would need only a short adap
tation period to this imaging modality, which would seem to be a valua
ble alternative to intra-operative cholangiography.