Stratification in the Gallbladder on Intravenous Cholangiography

Abstract

Errors in interpretation of intravenous cholangiograms are often made if 24-hour radiographs are not obtained. Three cases are presented in which radiographs, obtained 1/2--4 hours after administration of contrast material, failed to demonstrate gallstones in the visualized gallbladder. However, 24-hour radiographs revealed calculi in all three patients. Stratification of bile is thought to be the mechanism responsible. Delayed radiographs assure proper mixing of contrast material and bile, and provide optimal visualization of the gallbladder in patients undergoing intravenous cholangiography.

Stratification in the gallbladder during intravenous cholangiography

“…Therefore, we feel that when layering is present, it is absolutely necessary to extend the intravenous cholangiogram until the gallbladder is homogeneously opacified or for an interval of at least 4 hours before determining the presence or absence of disease. We have found it unnecessary to obtain delayed films at 24 hours, as suggested by Ounjian and Laing [7], if the gallbladder is well opacified at 4 hours.…”

“…Although the literature tends to emphasize that stratification is a normal phenomenon which may be mistaken for disease [2,3,5,6,8], it is equally important to remember that a radiolucent layer can conceal gallstones residing within it [4,[7][8][9]. Fortunately, physiologic layering is transient and will vanish before 4 hours; gallstones will not.…”