Which tissue has attenuation higher than muscle?

Which tissue has attenuation higher than muscle?

• A. Water
• B. Fat
• C. Bone and lung
• D. Blood

Answer: (C)

In ultrasound imaging, attenuation is the loss of acoustic energy as the sound wave travels through tissue. This loss depends on how the tissue’s density and acoustic impedance differ from its surroundings, causing absorption and scattering. Bone has a very high attenuation because it’s dense and causes strong absorption and scattering of the sound waves, plus it reflects much energy at interfaces, leading to limited transmission beyond the bone. The lung attenuates a lot as well because it contains air, which creates a huge impedance mismatch at the air–tissue interfaces. The energy is rapidly reflected and scattered, so less sound penetrates through the lung compared with muscle. Muscle, being a relatively uniform and moderately dense soft tissue, attenuates less than both bone and lung. So both bone and lung show higher attenuation than muscle.

In ultrasound imaging, attenuation is the loss of acoustic energy as the sound wave travels through tissue. This loss depends on how the tissue’s density and acoustic impedance differ from its surroundings, causing absorption and scattering. Bone has a very high attenuation because it’s dense and causes strong absorption and scattering of the sound waves, plus it reflects much energy at interfaces, leading to limited transmission beyond the bone. The lung attenuates a lot as well because it contains air, which creates a huge impedance mismatch at the air–tissue interfaces. The energy is rapidly reflected and scattered, so less sound penetrates through the lung compared with muscle. Muscle, being a relatively uniform and moderately dense soft tissue, attenuates less than both bone and lung. So both bone and lung show higher attenuation than muscle.