Dual-Energy X-ray Medical Imaging with Inverse Compton Sources: A Simulation Study

Abstract

It has been long recognized that dual-energy imaging could help to enhance the detectability of lesions in diagnostic radiology, by removing the contrast of surrounding tissues. Furthermore, X-ray attenuation is material specific and information about the object constituents can be extracted for tissue characterisation, i.e., to assess whether lesions represent a malignant or benign process. However, a true separation between the low and high energy components is not possible with conventional sources because of their broad X-ray spectrum, and the artifacts produced in the subtracted image can be only partially removed. Finally, dose issues have also prevented so far the application of dual-energy techniques within the clinical context. Very recently, a new intense and monochromatic X-ray source was proposed to fill the gap between a synchrotron radiation facility and the standard X-ray tube. Indeed, inverse Compton scattering (ICS) sources, which are based on the interaction of a powerful laser beam and a bright beam of relativistic electrons, are among the most promising innovative sources of monochromatic X and gamma radiation. In this contribution, we review the main features that allow an ICS source to meet the requirements of a medical imaging application. Specific examples of K-edge subtraction are then provided, to show the potential of ICS in clinical applications that require intravenous injection of a contrast medium.

Hard X-ray inverse Compton scattering at photon energy of 87.5 keV

“…This provides a gateway to much higher energy photons, where one may extend the reach of the source to over 100 keV, and on up to MeV or even GeV levels at modest electron beam energy. Compelling examples of potential application of monochromatic ICS X-ray sources in the service of medicine are X-ray computed tomographys [16] and photon activation therapy [17,18].…”

A new method for spatial mode shifting of a stabilized optical cavity for the generation of dual-color X-rays

“…X-ray imaging tests with ICS sources using contrast agents have been reported with (quasi-)monochromatic beam at a single energy above the K-edge of iodine [16,17], as well as using filtration of the same material used as contrast medium and specific reconstruction algorithms [18,19]. Also, simulations of the application of KES technique with X-ray beams of proposed ICS facilities demonstrated the potential of these sources in the case of coronary angiography and contrast-enhanced dual-energy mammography [20,21]. Nonetheless, dualenergy KES experiments with ICS have never been carried out so far, due to the lack of an effective implemen-tation of a fast dual-energy switch.…”

A new method for spatial mode shifting of stabilized optical cavities for the generation of dual-color X-rays

“…X-ray imaging tests with ICS sources using contrast agents have been reported with (quasi-)monochromatic beam at a single energy above the K-edge of iodine [16,17], as well as using ltration of the same material used as contrast medium and specic reconstruction algorithms [18,19]. Also, simulations of the application of KES technique with X-ray beams of proposed ICS facilities demonstrated the potential of these sources in the case of coronary angiography and contrast-enhanced dual-energy mammography [20,21]. Nonetheless, dual-energy KES experiments with ICS have never been carried out so far, due to the lack of an eective implementation of a fast dual-energy switch.…”