During the course of a sonographic exam, you notice lateral splaying of the echoes in the far field. What can you do to improve the image?

• A. Use the maximum acoustic power.
• B. Use the lowest line density setting.
• C. Increase the number of transmit focal zones and optimize their location.
• D. Decrease the scanning depth.

Answer: (C)

Lateral resolution and how the beam is focused determine how sharp structures appear side-to-side, especially in the far field. When echoes splay laterally, the beam is widening as it travels, so points become blurred along the lateral dimension. The way to counter that is to keep the beam narrow across more depths. Increasing the number of transmit focal zones and optimizing their locations creates multiple, depth-specific foci. Each focal zone narrows the beam at its designated depth, and together they keep the beam tight over a broader range. That reduces lateral beam width in the far field, sharpening lateral details and minimizing splaying.

The other options don’t address beam geometry: cranking up power can worsen artifacts and safety concerns without fixing focusing; lowering line density reduces spatial sampling and can degrade resolution; decreasing scanning depth changes what’s visible but doesn’t improve the beam’s lateral narrowing across depth.