High-ratio focused grids compared to lower-ratio grids are more effective because:

High-ratio focused grids are designed to be more effective at reducing the amount of scattered radiation that reaches the imaging receptor. This is primarily due to their construction and design, where the lead strips are positioned at an angle that coincides with the direction of the primary x-ray beam. Because these grids have a higher ratio of lead to interspace material, they are engineered to absorb more scattered radiation while allowing a higher percentage of the useful primary beam to pass through.

By effectively capturing and blocking out more scattering, high-ratio grids improve image contrast and overall image quality by reducing the fog that scattered radiation can introduce. This is particularly beneficial in diagnostic imaging where maintaining the integrity of the visual information is crucial.

The other options address aspects that are less relevant to the primary benefit of high-ratio focused grids. For instance, while increased positioning latitude can be a consideration in grid design, it is not inherently the defining characteristic of high-ratio grids. Similarly, while managing the useful beam is important, high-ratio grids are specifically designed to balance the absorption of both scattered radiation and useful beam rather than absorb more of the useful beam itself. Lastly, the weight and handling of grids are important practical considerations, but do not directly impact their efficacy in radiation management.