Which term describes the process by which the energy is redirected back toward the transducer due to encountering a boundary?

Which term describes the process by which the energy is redirected back toward the transducer due to encountering a boundary?

• A. Reflection
• B. Reflected beam
• C. Backscatter
• D. Diffraction

Answer: (A)

Energy redirected back toward the transducer at a boundary is described as reflection. When the ultrasound wave meets an interface between two media with different acoustic impedances, part of the energy is reflected back toward the transducer, creating the echoed signal. The amount that returns depends on the impedance difference—the greater the mismatch, the stronger the reflection. The term backscatter is related, describing echoes from scattering within tissue, not the straightforward boundary reflection itself. Diffraction, on the other hand, is the bending of waves around edges or through openings, which is a different phenomenon.

Energy redirected back toward the transducer at a boundary is described as reflection. When the ultrasound wave meets an interface between two media with different acoustic impedances, part of the energy is reflected back toward the transducer, creating the echoed signal. The amount that returns depends on the impedance difference—the greater the mismatch, the stronger the reflection. The term backscatter is related, describing echoes from scattering within tissue, not the straightforward boundary reflection itself. Diffraction, on the other hand, is the bending of waves around edges or through openings, which is a different phenomenon.