Which factors determine whether to use a grid?

Which factors determine whether to use a grid?

• A. kVp used
• B. Thickness of part
• C. Both kVp and thickness
• D. None of the above

Answer: (C)

Using a grid is about controlling scatter to improve image contrast. Scatter increases with both part thickness and the kilovoltage used, so the decision to grid depends on both factors. For a thin part or when low kVp is used, scatter is minimal and a grid isn’t usually needed; for thicker parts or higher kVp, scatter becomes more significant and a grid helps by absorbing scattered photons before they reach the image receptor. Keep in mind that adding a grid requires a higher exposure (grid factor) to maintain brightness, so you compensate accordingly. Thus, the best choice is that both the part’s thickness and the kilovoltage influence whether a grid is used.

Using a grid is about controlling scatter to improve image contrast. Scatter increases with both part thickness and the kilovoltage used, so the decision to grid depends on both factors. For a thin part or when low kVp is used, scatter is minimal and a grid isn’t usually needed; for thicker parts or higher kVp, scatter becomes more significant and a grid helps by absorbing scattered photons before they reach the image receptor. Keep in mind that adding a grid requires a higher exposure (grid factor) to maintain brightness, so you compensate accordingly. Thus, the best choice is that both the part’s thickness and the kilovoltage influence whether a grid is used.