The Selection Committee notes:
"The authors propose an extension to CT scanning which would produce a triad of images based on the detection of x-rays which are transmitted or scattered by different tissues. The method could be implemented on existing scanners, provided that all the detectors in the CT ring gantry could be sampled during a normal scan. The work presented in the paper is theoretical and it describes image reconstruction algorithms which produce maps of the attenuation coefficient, electron density, and an indicator of atomic number. This article is well written and clear in its objectives and methodology. Applications to radiation oncology, as well as to industrial and security imaging, are evident, following more experimental validation."