In tissue, higher frequencies have greater attenuation. Which statement best describes the effect of increasing frequency on attenuation?

• A. Decreased attenuation
• B. Increased attenuation
• C. No change in attenuation
• D. Attenuation depends only on tissue type

Answer: (B)

As ultrasound travels through tissue, energy loss (attenuation) grows with frequency. The attenuation coefficient in soft tissue is roughly proportional to frequency, about 0.5 dB per centimeter per megahertz. So when you raise the frequency, the energy is absorbed or scattered more per centimeter, leading to greater overall attenuation. That’s why higher-frequency waves attenuate more quickly and penetrate less deeply, though they offer better spatial resolution. The other ideas—attenuation decreasing, staying the same, or depending only on tissue type—don’t fit because the frequency itself directly boosts attenuation in tissue.