Lateral misregistration of a structure on the image can be caused by refraction. Which phenomenon is responsible?

Lateral misregistration of a structure on the image can be caused by refraction. Which phenomenon is responsible?

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

Answer: (B)

Lateral misregistration happens when sound waves bend as they pass from one tissue to another with a different propagation speed. This bending, or refraction, changes the direction of the wave path so the same structure sends echoes along a different line to the transducer. Since the imaging system reconstructs positions assuming straight-line propagation, the structure ends up appearing at a different lateral location than its true position. That shift is due to refraction, the phenomenon at play here. Reflection, absorption, and scattering affect signal strength or echo quality but don’t inherently cause this lateral displacement.

Lateral misregistration happens when sound waves bend as they pass from one tissue to another with a different propagation speed. This bending, or refraction, changes the direction of the wave path so the same structure sends echoes along a different line to the transducer. Since the imaging system reconstructs positions assuming straight-line propagation, the structure ends up appearing at a different lateral location than its true position. That shift is due to refraction, the phenomenon at play here. Reflection, absorption, and scattering affect signal strength or echo quality but don’t inherently cause this lateral displacement.