CHARACTERISTICS IN MACROSCOPIC CLASSIFICATION OF GALLSTONES AND THEIR EFFECTS ON VARIOUS IMAGING METHODS

According to “The New Classification of Gallstones” prepared by the Cholelithiasis committee. The Japan Society of Gastrointestinal Diseases, 53 gallstones from 54 patients were classified and analyzed the ingredients to study macroscopic characteristics and their effects on the imaging diagnosis. Most cholesterol stones presented in the gallbladder solitary, with a diameter of more than 5 mm. Combination stones presented in the gallbladder in a great variety of numbers, with a diameter of more than 1 cm. Mixed stones mainly presented in the gallbladder with a diameter of more than 1 cm, occurring in a number of more than two. Black stones mainly presented in the gallbladder with a variety of sizes and numbers. Calcium bilirubin stones presented in every site with various sizes and numbers. No particular effects of the stone size on simple abdominal X-ray examination were observed, but larger stones increased the diagnostic ability of CT and US. Black and calcium carbonate stones showed high diagnostic rates by both simple abdominal X-ray and CT. An improvement in correct diagnostic rate of cholesterol stones was also noted by CT. US was slightly inferior to the other in diagnosing pigment stones, and there occurred AS(-)s.