Which tissue has propagation speed of 1,600 m/s?

Which tissue has propagation speed of 1,600 m/s?

• A. Fat
• B. Liver
• C. Blood
• D. Muscle

Answer: (D)

Propagation speed of ultrasound waves varies by tissue because of differences in density and stiffness. Muscle transmits sound fastest among these options because it is denser and less compressible, so the speed of sound is higher—around 1,600 m/s fits closely with muscle tissue. Fat is softer and more compressible, so its speed is slower, typically nearer 1,450 m/s. Liver and blood have speeds in the soft-tissue range as well, but they are generally not faster than muscle. This is why muscle is the tissue with a propagation speed near 1,600 m/s.

Propagation speed of ultrasound waves varies by tissue because of differences in density and stiffness. Muscle transmits sound fastest among these options because it is denser and less compressible, so the speed of sound is higher—around 1,600 m/s fits closely with muscle tissue. Fat is softer and more compressible, so its speed is slower, typically nearer 1,450 m/s. Liver and blood have speeds in the soft-tissue range as well, but they are generally not faster than muscle. This is why muscle is the tissue with a propagation speed near 1,600 m/s.