Which term describes the redirection of an ultrasound beam in many directions at a rough boundary?

Which term describes the redirection of an ultrasound beam in many directions at a rough boundary?

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

Answer: (C)

When ultrasound meets a rough boundary, the surface irregularities break the wavefront into many small angles, sending energy in multiple directions. This diffuse redistribution is what we call scattering. It’s different from refraction, which bends the transmitted beam at a boundary with a speed change, or from reflection, which sends energy back along or near the incident path in a mostly single direction. Rayleigh scattering is a specific, small-particle case of scattering, not the general situation described by a rough boundary. So the term that best describes the redirection of the beam in many directions is scattering.

When ultrasound meets a rough boundary, the surface irregularities break the wavefront into many small angles, sending energy in multiple directions. This diffuse redistribution is what we call scattering. It’s different from refraction, which bends the transmitted beam at a boundary with a speed change, or from reflection, which sends energy back along or near the incident path in a mostly single direction. Rayleigh scattering is a specific, small-particle case of scattering, not the general situation described by a rough boundary. So the term that best describes the redirection of the beam in many directions is scattering.