What does the term 'bucky factor' refer to?

The term 'bucky factor' refers specifically to the increase in radiation exposure required when using a grid in radiographic imaging. When a grid is employed, it enhances image quality by reducing scatter radiation, but it also means that the radiographer must compensate by increasing the exposure technique to maintain a sufficient level of image density. This increase in exposure is what is quantified by the bucky factor.

For instance, if a grid is used that has a bucky factor of 4, the technologist must increase the milliampere-seconds (mAs) by that factor—meaning they would provide four times more radiation than they would without the grid—in order to achieve a properly exposed image. This is essential for maintaining the diagnostic quality of radiographs while utilizing grids effectively.

In contrast, determining the grid ratio involves the dimensions and arrangement of the lead strips in relation to the interspace material they are surrounded by, which focuses on how effectively the grid can reduce scatter radiation. Calculating primary transmission or identifying the thickness of grid strips does not involve the concept of how much additional exposure is necessary, which is the essence of the bucky factor.