Are multiple examinations of the gall-bladder helpful?

The pattern of use of the oral cholecystogram and ultrasonocholecystography in the investigation of 1014 patients prior to cholecystectomy was analysed. Three hundred and sixty-eight (36.3%) of our patients had both an oral cholecystogram and an ultrasound examination of the gallbladder. In 193 (52.4%) of these the initial investigation was positive: the second test in this group was rarely helpful and sometimes confusing. Overall the predictive value of a positive first study was 98.5%. We conclude that the use of further investigation following an initially positive result is not justified. By these criteria 18.5% of patients had an unnecessary second investigation.