Which tissue has speed closest to 1,540 m/s?

Which tissue has speed closest to 1,540 m/s?

• A. Soft tissue
• B. Lung tissue
• C. Fat tissue
• D. Liver tissue

Answer: (A)

The key idea is that ultrasound speed varies by tissue type, and 1,540 m/s is the standard speed assigned to soft tissue. Soft tissues like muscle and connective tissue have mechanical properties that yield a propagation speed right around 1,540 m/s, so they match the given value closely. Lung tissue, filled with air, slows waves dramatically—speed drops to only a few hundred m/s. Fat tissue is a bit slower than soft tissue, roughly around 1,450 m/s, which is farther from 1,540 than soft tissue. Liver tissue is typically cited near 1,560–1,580 m/s, also close but slightly farther from 1,540 than soft tissue in the standard reference. So soft tissue is the best match to 1,540 m/s.

The key idea is that ultrasound speed varies by tissue type, and 1,540 m/s is the standard speed assigned to soft tissue. Soft tissues like muscle and connective tissue have mechanical properties that yield a propagation speed right around 1,540 m/s, so they match the given value closely. Lung tissue, filled with air, slows waves dramatically—speed drops to only a few hundred m/s. Fat tissue is a bit slower than soft tissue, roughly around 1,450 m/s, which is farther from 1,540 than soft tissue. Liver tissue is typically cited near 1,560–1,580 m/s, also close but slightly farther from 1,540 than soft tissue in the standard reference. So soft tissue is the best match to 1,540 m/s.