What percentage of gallstones is calcified?
About 15% of gallstones are radiopaque on plain abdominal radiography. Calcification is detected in about 30% to 40% of gallstones on CT. CT detects about 80% of calcified or noncalcified gallstones. Cholesterol gallstones appear as low-attenuation filling defects, often floating in bile, although often similar in attenuation to surrounding bile. Ultrasonography (US) detects about 95% of gallstones.
Gallstones are an example of concretions formed in the abdomen. The calcification in such concretions usually occurs around a central nidus of organic or inorganic foreign matter, thrombus, focal pus, or cellular debris. Such calcifications occur within the lumina of tubular structures, such as blood vessels, bile ducts, or ureters, or within hollow viscera such as the gallbladder or urinary bladder. Concretions may have a round, ovoid, branched, or spiculated shape.
