When using a grid, what happens to the required mAs as the grid ratio increases?

When a grid is used in radiographic imaging, its primary function is to absorb scatter radiation that does not contribute to the formation of the image. As the grid ratio increases, this means that the grid has a greater density of lead strips in relation to the interspace material (usually aluminum), which enhances its ability to clean up scatter.

However, a higher grid ratio also results in a reduction in the amount of primary radiation that can pass through to the film or digital detector, necessitating an increase in the milliampere-seconds (mAs) to achieve the same level of image density. Therefore, as the grid ratio increases, the required mAs must also increase to compensate for the higher level of absorption of primary radiation by the grid. This ensures that enough radiation reaches the receptor to produce an image of adequate quality.