What variable change would increase receptor exposure in a chest x-ray taken with a 12:1 grid?

To increase receptor exposure in a chest x-ray taken with a 12:1 grid, decreasing the grid ratio is an effective approach. A grid is used in radiography to reduce scatter radiation and improve image contrast. However, grids also absorb some of the primary radiation that contributes to receptor exposure.

A 12:1 grid has a high ratio and will absorb a significant amount of primary radiation. When the grid ratio is decreased, less primary radiation is absorbed, allowing more of the useful radiation to reach the receptor. This results in increased receptor exposure, as the reduction in grid ratio reduces the amount of primary beam attenuation.

In contrast, increasing the grid ratio would further reduce receptor exposure because it would lead to more significant absorption of primary radiation. Increasing filtration would also decrease receptor exposure by removing lower-energy photons that do not contribute effectively to the image quality. Decreasing exposure time could reduce receptor exposure by minimizing the amount of radiation delivered regardless of other settings. Thus, decreasing the grid ratio is the most effective variable adjustment to increase receptor exposure in this scenario.