AT TIMES it is difficult to differentiate between bubbles and spherical calculi in the common bile duct and hepatic ducts during operative and postoperative cholangiography.
When calculi are cubed, pyramidal, or faceted, or have angular edges, they may be identified with ease. But if stones are spherical or oval in shape, they may easily be interpreted as bubbles—or more significantly, spherical bubbles may be reported as calculi.
Kantor et al1 have stated that stones can change position in the ducts during cholangiography as do air bubbles, but that a shadow which rises as the patient is changed from Trendelenburg to a supine position is more likely to represent an air bubble which is seeking the higher level. However, we have observed that the density of some calculi permits them to float up and down in the same manner as do air bubbles.
It was observed on a carpenter's spirit
SHULMAN AG. Differentiation Between Spherical Calculi and Bubbles in the Common and Hepatic DuctsAn In-Vitro Study. Arch Surg. 1965;91(3):478-479. doi:10.1001/archsurg.1965.01320150108019