Which tissue feature contributes most to attenuation of ultrasonic waves in the body?

Which tissue feature contributes most to attenuation of ultrasonic waves in the body?

• A. Reflection
• B. Scattering
• C. Absorption
• D. Refraction

Answer: (C)

Attenuation of ultrasound in tissue is driven most by absorption—the conversion of sound energy into heat as it interacts with tissue molecules. As the wave travels, some of its energy is dissipated through viscous and relaxation processes, and this loss accumulates with distance. Absorption also increases with frequency, so higher-frequency waves attenuate more. Reflection and scattering move energy out of the forward path but are more about redirecting energy at boundaries or due to microstructures, not the primary depth-dependent loss. Refraction changes direction without inherently dissipating energy. So the tissue feature that contributes most to attenuation is absorption.

Attenuation of ultrasound in tissue is driven most by absorption—the conversion of sound energy into heat as it interacts with tissue molecules. As the wave travels, some of its energy is dissipated through viscous and relaxation processes, and this loss accumulates with distance. Absorption also increases with frequency, so higher-frequency waves attenuate more. Reflection and scattering move energy out of the forward path but are more about redirecting energy at boundaries or due to microstructures, not the primary depth-dependent loss. Refraction changes direction without inherently dissipating energy. So the tissue feature that contributes most to attenuation is absorption.