Ultrasonography of the gallbladder in patients with a clinical suspicion of acute cholecystitis.

The prevalence of ultrasonographic (US) signs described in the literature in cases of acute cholecystitis (wall thickening, increased volume, roundness and local tenderness of the gallbladder, an anechoic layer in the gallbladder wall and cholelithiasis were studied in 136 consecutive patients referred for US examination with clinically suspected acute cholecystitis (AC). Of the patients, 56 had AC, 21 chronic cholecystitis, 2 carcinoma of the gallbladder, and 57 extrabiliary diseases. In AC, frequent findings in addition to cholelithiasis were wall thickening (79%) and an increased volume (64%). Almost one third of the patients had local tenderness (sonographic Murphy sign) (29%), and 27% of the gallbladders had a rounded form. All these features were, however, rather frequently detected also in chronic cholecystitis (5-33%) and in the 2 carcinoma patients, and also sporadically in extrabiliary diseases. A anechoic layer in the gallbladder wall was the only sign confined to AC, but was detected only in 2 cases. Roundness of the gallbladder occurred only in either acute or chronic cholecystitis. The combination of at least two diagnostic findings was noticed in 91% in AC, rather frequently in chronic cholecystitis (43%) and in both carcinoma patients, but only in 1 patient in the extrabiliary disease group. Three or more signs were seen only in gallbladder diseases (48%), but AC, chronic cholecystitis or carcinoma groups could not be completely differentiated (prevalences 63, 10 and 50%).