You can reduce beam width to improve spatial resolution in the image by which of the following?

• A. Focusing
• B. Decreasing aperture
• C. Decreasing transducer diameter
• D. Increasing backing material

Answer: (A)

Narrowing the beam width improves spatial resolution because two closely spaced reflectors are easier to separate when energy is confined to a smaller lateral area. Focusing achieves this by converging the ultrasound waves to a focal region, which narrows the beam at that depth. This direct reduction in beam width enhances lateral (side-to-side) resolution in the focused zone.

Decreasing aperture or transducer diameter would widen the beam instead of narrowing it, leading to poorer lateral resolution. Increasing backing material mainly affects pulse duration and bandwidth, improving axial resolution more than the lateral beam width, so it doesn’t meaningfully reduce beam width to boost spatial resolution.