The non-visualized gallbladder by ultrasonography implications and differential diagnosis

The findings in 42 consecutive patients in whom the gallbladder or its lumen were not visualized ultra-sonographically were reviewed retrospectively for evidence of gallbladder disease. The series contains two groups of patients - the larger comprised 32 patients in whom the gallbladder was represented only by a dense echogenic focus, with acoustic shadowing, in the right upper quadrant, thought to be due to cholelithiasis in a small contracted gallbladder. The accuracy of this finding in predicting gallbladder disease was 96%. The smaller group consisted of eight patients in whom the gallbladder was not visualized. In seven patients with follow-up, the accuracy of this finding in predicting gallbladder disease was only 71%. Dense echoes in the right upper quadrant were not always due to cholelithiasis but to emphysematous cholecystitis in one patient, porcelain gallbladder in a second, and agenesis of the gallbladder in a third.