Which interface is known to heat more with ultrasound due to higher energy absorption?

Which interface is known to heat more with ultrasound due to higher energy absorption?

• A. Tendon-bone interface
• B. Bone-muscle interface
• C. Muscle-fat interface
• D. Skin-air interface

Answer: (B)

The main idea is that heating from therapeutic ultrasound depends on how much energy the tissue absorbs, which is driven by attenuation and acoustic properties. Bone absorbs ultrasound energy far more than soft tissues because of its high density and mineral content. When ultrasound travels through muscle and then meets bone, a large portion of the energy is absorbed by the bone at that interface, converting to heat—often more than at the other interfaces. The skin–air interface reflects most of the energy and transmits very little, so heating is minimal there. Fat–muscle has lower attenuation than bone, so it heats less, and while tendon–bone involves bone, the direct absorption by bone at the bone–muscle junction tends to produce greater heating. So the bone–muscle interface is the one known to heat more due to higher energy absorption by bone.

The main idea is that heating from therapeutic ultrasound depends on how much energy the tissue absorbs, which is driven by attenuation and acoustic properties. Bone absorbs ultrasound energy far more than soft tissues because of its high density and mineral content. When ultrasound travels through muscle and then meets bone, a large portion of the energy is absorbed by the bone at that interface, converting to heat—often more than at the other interfaces. The skin–air interface reflects most of the energy and transmits very little, so heating is minimal there. Fat–muscle has lower attenuation than bone, so it heats less, and while tendon–bone involves bone, the direct absorption by bone at the bone–muscle junction tends to produce greater heating. So the bone–muscle interface is the one known to heat more due to higher energy absorption by bone.