What is grid cutoff in radiography?
Grid cutoff is the loss of primary radiation that occurs when the image of the lead strips are projected wider than they would be with ordinary magnification. This is the results of poor geometric relationship between the primary beam and the lead foils strips of the grid. The grid cutoff means, no primary radiation reaches the film when the projected images of the lead strips are thicker then the width of the interspaces. The amount of cutoff is always greatest with high ratio grids and short grid focus distance.
There are following conditions are grid cutoff.
A) Focused grids used upside-down.
B) Grid angulation.
C) Focus grid distance decentering.
D) Combined lateral and focus grid distance decentering.
What is main effect of grid cutoff in radiography?
The main effect of grid cut-off in radiography is loss of image contrast, which can make it difficult to see small or subtle structures in the image. This is because the grid absorbs some of the x-ray beam, which reduces the amount of radiation that reaches the image receptor. This can also lead to increased radiation exposure for the patient, as more radiation is needed to produce an image of adequate quality. Additionally, grid cut-off can result in poor visualization of the edges of the body part being imaged, which can make it difficult to accurately diagnose certain conditions.