Which term describes energy returning to the transducer in a mirror-like reflection during organized interaction?

• A. Backscatter
• B. Diffuse
• C. Specular
• D. Rayleigh scattering

Answer: (C)

Specular reflection occurs when the ultrasound wave meets a smooth, organized boundary, so the energy returns to the transducer along a mirror-like path. Because the boundary is large and smooth relative to the wavelength, the angle of incidence equals the angle of reflection, producing a strong, directional echo that retraces the transducer’s path. This is in contrast to backscatter, which comes from many small or rough features and returns energy in multiple directions; diffuse scattering, which sends energy in many directions due to rough surfaces; and Rayleigh scattering, which involves very small scatterers and a broader, weaker angular distribution. Thus, the mirror-like, organized return is best described as specular reflection.