What should be the new milliampere-seconds value if an 8:1 grid is added to a nongrid exposure of 80 kVp and 8 mAs?

When an 8:1 grid is added to an exposure, it impacts the amount of radiation that reaches the image receptor. Grids are used to improve image quality by reducing scatter radiation, and they also require an increase in the milliampere-seconds (mAs) to maintain image brightness and contrast.

For an 8:1 grid, it is common practice to increase the mAs by a factor of around 2 to 4, depending on the specific grid's characteristics. In this case, applying the typical increase suggested for an 8:1 grid translates to doubling the original mAs value.

Starting with the initial exposure of 8 mAs, when the grid is added, the appropriate calculated mAs becomes 8 mAs multiplied by 4, resulting in 32 mAs. This increase compensates for the additional absorption of the primary beam by the grid and ensures that the image remains properly exposed.

Thus, adjusting the mAs to 32 mAs when adding an 8:1 grid aligns with standard practice in diagnostic imaging to ensure optimal image clarity while managing the effects of scatter radiation effectively.