The X-ray-based cancer imaging simulation toolkit (XCIST) project is supported by the National Cancer Institute of the National Institutes of Health under Award Number U01CA231860 (ITCR grant).
This toolkit includes software developed by Members of the Geant4 Collaboration ( http://cern.ch/geant4 ). Specifically it builds on the X-ray attenuation cross-sections produced by Geant4.
For more information, please visit: https://github.com/xcist/documentation/wiki