What does attenuation describe in ultrasound?

What does attenuation describe in ultrasound?

• A. Reflection at tissue interfaces
• B. Amplification of signal
• C. Speed increase of sound in tissue
• D. Loss of sound energy as it travels through medium

Answer: (D)

Attenuation is about the beam losing energy as it moves through tissue. As ultrasound travels, energy is diminished by absorption (tissue converting some of the sound energy to heat) and scattering (energy pushed in many directions) and, to some extent, by geometric spreading. This makes the signal weaker with depth, and higher-frequency beams attenuate more quickly, trading depth penetration for better resolution. This concept is distinct from reflections at interfaces (which produce echoes) and from the speed of sound (which affects travel time). So describing attenuation as the loss of sound energy as it travels through the medium is the best fit.

Attenuation is about the beam losing energy as it moves through tissue. As ultrasound travels, energy is diminished by absorption (tissue converting some of the sound energy to heat) and scattering (energy pushed in many directions) and, to some extent, by geometric spreading. This makes the signal weaker with depth, and higher-frequency beams attenuate more quickly, trading depth penetration for better resolution. This concept is distinct from reflections at interfaces (which produce echoes) and from the speed of sound (which affects travel time). So describing attenuation as the loss of sound energy as it travels through the medium is the best fit.