Relationship of gallbladder contour, fasting volume and emptying to body size indices in normal subjects and patients with gallstones.

Fasting gallbladder volume and fasting gallbladder roundness index (ratio of anteroposterior diameter to gallbladder length) were estimated by ultrasonography in 182 normal subjects and 43 patients with gallstones and correlated to body size indices. In 20 of the normal subjects, gallbladder emptying was assessed and correlated to gallbladder roundness index. Gallstone patients had a larger fasting gallbladder volume as compared to normals (42 +/- 10 vs 22 +/- 7 (SD) ml, p < 0.001). Gallbladder fasting volume was found to be significantly related to roundness index (p < 0.001) and body surface area (p < 0.0001) in normals, but not in patients with cholelithiasis. Subjects with a roundness index > 0.3 showed a less-complete gallbladder emptying as compared to those with a roundness index < 0.3 (p < 0.01). It is concluded that increased body size, but not obesity alone, is associated with an increased gallbladder fasting volume, and that a rounder gallbladder tends to empty less completely.