Abstract
We investigated the effects of different degrees of misalignment on the performance of new grids in bedside radiography. Two types of new grids(a conventional grid with a grid ratio of 3:1 and a parallel hole grid)designed for bedside radiography were compared with a conventional 5:1 grid. The effects of scatter fraction, contrast improvement factor, bucky factor, and tolerance to misalignment on grid performance were examined. The scatter rejection and contrast improbvement of the new grids were significantly lower compared with a 5:1 grid at accurate alignment. However, the two new grids have much more tolerance to misalignment than the conventional grid. The two new grids may be used for bedside radiography without the need for accurate alignment.
