Attenuation of X-rays

When the x-ray passes through an absorber (e.g., oral tissues), it gets differentially absorbed by what constitutes the absorber and the thickness of each component. When the x-ray beam exits this absorber, it will demonstrate varying intensity levels. This variation will be recorded on a radiographic receptor as different densities generating the radiographic contrast. Thick absorbers such as aluminum will have a brighter density than the densities that thin absorbers will produce. (Figure 8).^1,2,3,4,6

Figure 8. Photo and radiographic image of an aluminum stepwedge. The thin steps are darker than the thick steps.

Figure 8. Photo and radiographic image of an aluminum stepwedge. The thin steps are darker than the thick steps.