Gallstone images on plain film and endoscopic retrograde cholangiopancreatography.

Different compositions of gallstone merit different treatments if a non-surgical method is chosen for these patients. In this study, gallstones collected from 125 patients were classified into cholesterol (pure, combination, mixed N = 28), brown (N = 64) and black (N = 41) stones by the Gallstone Classification of the Japanese Study Group (1986). Plain film and endoscopic retrograde cholangiopancreatography (ERCP) were reviewed in an attempt to predict the composition of the stones. We found that shape and location were highly correlated with stone composition. Most of the sandy stones were black stones (15/19, 79%); and 48% (10/21) of the irregular stones were brown stones; 70% (14) of facet stones were brown stones, 30% cholesterol stones. Stones in the gallbladder tended to be of the cholesterol type (47%, 13/28), 64% (51/81) of the bile duct stones were brown stones and 69% (11/16) of the gallbladder and bile duct stones were brown stones. We therefore conclude that imaging studies using plain film and ERCP is a fairly accurate means of predicting the composition of gallstone.