What Is Grid Ratio.
Grid ratio is the ratio of hight of lead strip (h) and distance (d) between lead strip in grid.
Grid radio= h/d
The ratio is the parameters which define the ability to removing the scattered radiation from the x-ray film. The range of grid radio is 4:1 to 16:1. The grid ratio is depends on the KVp. Low grid ratio used for low KVp and high grid ratio used for high KVp.The grid lead strips are about 0.05 mm thick. The range of grid frequency most is 60 to 110 lines/ inches or 25 to 45 lines/cm. In mammography the low grid ratio used, the range is 2:1 to 4:1. Because it work in low KVp technique.
