"Most commonly observed grid cutoff, most prominent at a short source-to-image receptor distance (SID), due to the divergent beam geometry. A small SID leads to undesired absorption of the primary x-ray beam via the grid lines. Taking on the appearance of an overall decrease in optical density or variable optical density across the image (one side appearing less dense than the other)."
"Most commonly observed grid cutoff, most prominent at a short source-to-image receptor distance (SID), due to the divergent beam geometry. A small SID leads to undesired absorption of the primary x-ray beam via the grid lines. Taking on the appearance of an overall decrease in optical density or variable optical density across the image (one side appearing less dense than the other)."
"distance to grid cutoff = SID / grid ratio"
"A sound method in identifying cutoff is to compare the bony detail each side of the image, images with grid cutoff, for example, an AP erect chest will have a notable difference in bony detail of the shoulder girdles."
Expected headings
"Parallel grid cutoff"
"Crossed grid cutoff"
"A crossed grid is two parallel grids running perpendicular to each other to reduce scatter in both directions; it has been proven to clean up scatter radiation more effectively than parallel grids. However, due to the beam geometry, the primary beam must be centred on the grid's centre, at the same angle as the crossed grid. Any deviation can cause significant grid cutoff, creating a decrease in primary beam reaching the detector often unilaterally, with the potential to simulate pathology."