Ultrasound energy is absorbed by tissues primarily through which mechanism?

Ultrasound energy is absorbed by tissues primarily through which mechanism?

• A. Reflection
• B. Refraction
• C. Conversion
• D. Scattering

Answer: (C)

The main thing being tested is how ultrasound energy is taken up by tissues and turned into something different. In soft tissues, most of the energy that isn’t reflected back or scattered is absorbed because the mechanical vibrations cause molecular friction and viscous losses. This converts the acoustic energy into heat, so absorption is effectively the conversion of sound energy into thermal energy. This conversion process is why tissues heat up with ultrasound exposure, and it depends on factors like frequency, tissue type, and intensity. Reflection, refraction, and scattering mostly describe how energy is redirected or split rather than how it’s absorbed to become heat.

The main thing being tested is how ultrasound energy is taken up by tissues and turned into something different. In soft tissues, most of the energy that isn’t reflected back or scattered is absorbed because the mechanical vibrations cause molecular friction and viscous losses. This converts the acoustic energy into heat, so absorption is effectively the conversion of sound energy into thermal energy. This conversion process is why tissues heat up with ultrasound exposure, and it depends on factors like frequency, tissue type, and intensity. Reflection, refraction, and scattering mostly describe how energy is redirected or split rather than how it’s absorbed to become heat.