Validation of the Methods Estimating Gallbladder Volume

The in vivo and in vitro experiments were performed on forty dogs to assess the accuracy and to compare three methods estimating gallbladder (GB) volume. During in vivo experiments, fasting GB volumes in normal dogs were compared with dogs exhibiting GB wall thickness. Another group of dogs with the GB shapes resembling the ellipsoid was studied in vivo and in vitro. First, the ellipsoid method was used to estimate the fasting GB volume. Then, the dogs were sacrificed, GBs ligated and the GB volumes were estimated anew. There were no marked differences between these measurements. The bile was removed from the GBs and its volume was compared with the results of previous in vivo estimation. Furthermore, the increasing portions of bile were introduced into these GBs and the estimations of GB volume were performed. The same method was validated with the use of artificial GB models. Finally, the ellipsoid method was compared with random point and sum-of-cylinder methods in healthy dogs with different GB shapes. The accuracy was: sum of cylinder method > random point method > ellipsoid method.