[Methods estimating gallbladder volume]

An increasing incidence of liver and biliary tract diseases brings about an increasing necessity of their precise diagnosis. The procedure of estimation of gallbladder volume seems to be useful in ultrasonic examination of gallbladder motility and is widely applied in human medicine all over the world. The methods estimating gallbladder volume can be divided into two groups. The first group comprises the application of rather simple formulas approximating the actual gallbladder shape to the given geometric solid. These methods are precise when the actual gallbladder shape is at least roughly similar to the approximated solid. The second group is more uniform methods since their precision is principally not dependent on the gallbladder shape. The aim of this article was the description and comparison of more or less known methods ascribed to the both groups. Among the methods of the first group, one of the firstly applied and less precise methods usually lowering the results is the method approximating the gallbladder shape to a cone. More common and precise is the ellipsoid method, but this method sometimes also approximates the gallbladder shape not very accurately. The other methods approximating the gallbladder shape to a barrel, cylinder, sphere, trapezoid or frustum of cone and the modifications of some of these methods like the method of cone and ellipsoid, are comparable with the ellipsoid method. The planimetric group of the methods can be included into the second group and in these methods the calculation of the area of the organ longitudinal image is followed by estimation of the organ's volume. Other validated methods are: the random points method based on the known group of mathematical methods (Monte Carlo) representing practically one ofplanimetric methods, the commonly used sum-of-cylinder method and the Simpson method. The reported data indicate that Simpson method is currently the most accurate method estimating the gallbladder volume while the planimetric and sum-of-cylinder methods are believed to be also accurate. The applied method estimating gallbladder volume should be selected in the manner that guarantees its possibly maximal accuracy.