Figure 1
(a) Imaging process of the radiography for trabecular bone. The incident X-ray is refracted at the boundary of the objects that have different refractive indices for X-rays according to Snell's law. When the refractive index of X-rays for bone marrow, n1, is greater than that for compact or trabecular bone, n2, there follow relationships between angles of incidence and refraction: θ1 < θ2 and θ3 > θ4. The broken lines are the normal to the sample surface. Typical intensity distribution on the film is also shown in the figure; higher image intensity corresponds to a darker area on the film. (b) Imaging process of radiography for a small fracture. The phase shift of the X-rays arises at the region within depth L from the surface. X-rays penetrating the semitransparent single slit interfere and cause the interference fringe on the film. Typical intensity distribution on the film is shown in the figure. The intensity distribution was well explained by Fresnel diffraction of X-rays. The definition of the image densities was the same as for (a). |