EN
To develop a new animal model for gallbladder ultrasonography 16 adult sheep of both sexes were used. Ultrasonographic examinations were performed in fed or fasted sheep every 30 min for 3-5 h. Every gallbladder was visualized, then its maximal length, height and width were measured. Afterwards, the gallbladder volume was calculated with three methods. The maximal and minimal values of gallbladder volume in both fed and fasted animals differed significantly (p < 0.05) indicating the existence of gallbladder contractions detectable in both states examined. The results of gallbladder volumes calculated with various methods were also significantly different. The values obtained from the method describing the gallbladder as a cone were about 50% lower than that obtained from two ellipsoid methods. The validation study showed that the true value remained somewhere between the values obtained indirectly. This warrants further investigation, however.