Which term describes loss in intensity from bending of the sound beam at a curved structure?

• A. Edge Shadow
• B. Field of View
• C. Enhancement
• D. Cine Loop

Answer: (A)

When a sound beam meets a curved boundary, the energy is redirected by refraction at that curved interface. The rays near the edge of the curve tend to bend away from the region just beyond the edge, so fewer ultrasound waves reach that area. This redistribution of energy creates a dark, shadow-like region along and just beyond the curve—the edge shadow. It’s a geometry-driven artifact rather than simply a property of the tissue’s attenuation.

The other terms describe different concepts: field of view is what portion of anatomy is displayed on the screen; enhancement refers to increased brightness behind a structure due to its attenuation or scattering properties; cine loop is the ability to replay a sequence of frames.