Absorption describes energy transfer to tissue as heat

Absorption describes energy transfer to tissue as heat

• A. Absorption is the conversion of mechanical energy to heat within tissues.
• B. Absorption is the reflection of sound at tissue boundaries
• C. Absorption is the transmission of energy through tissue without heating
• D. Absorption is the generation of electricity in tissue

Answer: (A)

Absorption is the process by which acoustic energy is converted into heat within tissue. When ultrasound waves enter the body, some energy is reflected at tissue boundaries due to impedance differences, some is transmitted deeper, and the portion that remains is absorbed by the tissue. This absorbed energy causes molecular interactions and friction that produce heating, which is the therapeutic thermal effect clinicians aim for. Higher frequency waves tend to be absorbed more readily, increasing heating but reducing depth of penetration. Attenuation of the beam equals absorption plus scattering, but absorption specifically accounts for the heat generation in tissue. The other options describe reflection, transmission without heating, and electricity generation, none of which capture the heat-producing nature of absorption.

Absorption is the process by which acoustic energy is converted into heat within tissue. When ultrasound waves enter the body, some energy is reflected at tissue boundaries due to impedance differences, some is transmitted deeper, and the portion that remains is absorbed by the tissue. This absorbed energy causes molecular interactions and friction that produce heating, which is the therapeutic thermal effect clinicians aim for. Higher frequency waves tend to be absorbed more readily, increasing heating but reducing depth of penetration. Attenuation of the beam equals absorption plus scattering, but absorption specifically accounts for the heat generation in tissue. The other options describe reflection, transmission without heating, and electricity generation, none of which capture the heat-producing nature of absorption.