Compositional images from the diffraction enhanced Imaging technique

Diffraction Enhanced Imaging (DEI) derives X-ray contrast from absorption, refraction, and extinction. While the refraction angle image of DEI represents the gradient of the projected mass density of the object, the absorption image measures the projected attenuation ((mu t) over bar) of an object. Using a simple integral method it has been shown that a mass density image ((rho t) over bar) can be obtained from the refraction angle image. It then is a simple matter to develop a combinational image by dividing these two images to create a mu/rho image. The mu/rho is a fundamental property of a material and is therefore useful for identifying the composition of an object. In projection X-ray imaging the mu/rho image identifies the integrated composition of the elements along the beam path. When applied to DEI computed tomography (CT), the image identifies the composition in each voxel. This method presents a new type of spectroscopy based in radiography. We present the method of obtaining the compositional image, the results of experiments in which we verify the method with known standards and an application of the method to breast cancer imaging. (c) 2006 Elsevier B.V. All rights reserved.