Which structure tends to be the most attenuating among the following when imaging a sonogram?

Which structure tends to be the most attenuating among the following when imaging a sonogram?

• A. Blood
• B. Calcification
• C. Bile
• D. Soft tissue

Answer: (B)

Attenuation on ultrasound is the loss of sound energy as it travels through tissue. Structures that are dense and highly reflective block and scatter more of the beam. Calcifications have a much higher acoustic impedance than surrounding soft tissues, so they reflect a large portion of the energy and absorb it, producing bright echoes at the surface and little energy to pass through—often with a dark posterior shadow. Blood and bile are fluids with low attenuation, and soft tissue attenuates less than calcium. So, calcifications tend to be the most attenuating among the options.

Attenuation on ultrasound is the loss of sound energy as it travels through tissue. Structures that are dense and highly reflective block and scatter more of the beam. Calcifications have a much higher acoustic impedance than surrounding soft tissues, so they reflect a large portion of the energy and absorb it, producing bright echoes at the surface and little energy to pass through—often with a dark posterior shadow. Blood and bile are fluids with low attenuation, and soft tissue attenuates less than calcium. So, calcifications tend to be the most attenuating among the options.