title: Ultrasonic properties of biliary calculi.
abstract: The authors show that the intrinsic ultrasonic attenuation of a gallstone is an important factor in determining the degree of shadowing. B scans in vivo and in vitro demonstrated that stones with higher attenuation also show the most shadowing. In addition, attenuation can be correlated with physical structure: more highly attenuating stones tend to have the largest percentage of crystalline material, a larger average crystal size, and a more rigid structure. The authors recommend that higher-frequency transducers be used where possible if nonshadowing structures are seen in the gallbladder.
mesh_terms: D002769:Cholelithiasis / Q000175:diagnosis*; D006801:Humans; D066298:In Vitro Techniques; D014159:Transducers; D014465:Ultrasonics