Proposal of a Novel Diffraction Enhanced Imaging Setup Based on Polycapillary X-ray Optics

Abstract

Diffraction Enhanced Imaging (DEI) is a recent technique developed to improve the diagnostic capabilities of radiography by exploiting coherently scattered X-rays to generate images that provide higher contrast than conventional transmission imaging. Earlier experiments, carried out in the synchrotron environment using a mechanical parallel-hole collimator coupled to a 2D X-ray imager, confirmed the potential of this technique in mammography. The main limitations of DEI come from the detection system, the requirement of the synchrotron source and the use of a mechanical multi-hole collimator, which limits the achievable spatial resolution and also increases the acquisition time. New developments in polycapillary optics technology and in 2D detectors enable a significant upgrade of DEI setups. In order to handle the above mentioned limitations, a microfocus X-ray tube coupled to a polycapillary semi-lens, was used to deliver a collimated X-ray beam. A second polycapillary lens for the angle selection was coupled to the detector to achieve high spatial resolution. The detector was upgraded to the Controlled Drift-Detector (CDD), a novel 2D X-ray imager with energy resolving capability of spectroscopic quality. This paper introduces this novel setup and presents the results of its experimental qualification. Images of phantoms both in transmission and in diffraction modes will be presented to evaluate the system performance.