Which pairing describes the two characteristics of more attenuation?

Which pairing describes the two characteristics of more attenuation?

• A. Longer distances and Lower frequencies
• B. Longer distances and Higher frequencies
• C. Shorter distances and Higher frequencies
• D. Shorter distances and Lower frequencies

Answer: (B)

Attenuation in ultrasound increases with both how far the sound travels and how high the frequency is. As the wave moves through tissue, energy is lost to absorption and scattering, and this loss accumulates over longer distances. At the same time, higher frequencies are absorbed more readily by tissue, causing greater attenuation per unit distance. So the combination of a longer path and a higher frequency produces the most attenuation, which is why longer distances paired with higher frequencies describe more attenuation. If either distance is reduced or frequency lowered, attenuation decreases accordingly.

Attenuation in ultrasound increases with both how far the sound travels and how high the frequency is. As the wave moves through tissue, energy is lost to absorption and scattering, and this loss accumulates over longer distances. At the same time, higher frequencies are absorbed more readily by tissue, causing greater attenuation per unit distance. So the combination of a longer path and a higher frequency produces the most attenuation, which is why longer distances paired with higher frequencies describe more attenuation. If either distance is reduced or frequency lowered, attenuation decreases accordingly.