US Patent 8401270 Examination of a region using dual-energy radiation

A first image including a projection of a portion is generated based on data representing attenuation of higher-energy radiation having a peak energy of at least 1 MeV that passes through a portion of an inspection volume. A second image including a projection of the portion is generated based on data representing attenuation of lower-energy radiation passing through the portion of the inspection volume. A dual-pixel image is created from the first image and the second image. A region of interest is selected from the dual-pixel image. A first basis function that is derived from an attenuation characteristic associated with the region of interest is selected. The region of interest is represented in terms of an amplitude associated with the first basis function and an amplitude associated with the second basis function.