Which term describes the energy that returns to the transducer after hitting a boundary?

Which term describes the energy that returns to the transducer after hitting a boundary?

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

Answer: (A)

When ultrasound waves meet a boundary with a different acoustic impedance, part of the energy is sent back toward the transducer. The energy that returns is the reflected beam—the echo that is detected to create the image. This term focuses on the actual returning signal, as opposed to the general process of reflection, which is the wave bouncing, or backscatter, which refers more to energy scattered in many directions from multiple structures. Diffraction, by contrast, is the bending of waves around edges and isn’t about energy returning from a boundary.

When ultrasound waves meet a boundary with a different acoustic impedance, part of the energy is sent back toward the transducer. The energy that returns is the reflected beam—the echo that is detected to create the image. This term focuses on the actual returning signal, as opposed to the general process of reflection, which is the wave bouncing, or backscatter, which refers more to energy scattered in many directions from multiple structures. Diffraction, by contrast, is the bending of waves around edges and isn’t about energy returning from a boundary.