How does decreasing the primary beam field size affect scatter radiation reaching the image receptor?

Decreasing the primary beam field size reduces the area of tissue that is irradiated. This limitation on the irradiated area leads to a decrease in the amount of scatter radiation produced. Scatter radiation occurs when the primary beam interacts with matter and deflects off in various directions. When a smaller field size is used, there is less tissue volume for the radiation to penetrate, resulting in less scatter generated. Additionally, since less scatter radiation reaches the image receptor, this can improve image quality by reducing the amount of unwanted radiation that could contribute to fogging or decreased contrast on the image. Therefore, reducing the size of the primary beam effectively decreases the scatter radiation that reaches the image receptor.