Beam hardening and metal artefacts

X-ray sources produce a polychromatic spectrum which is altered when interacting with the sample. Due to this alteration, cupping effects in the reconstructed data of a CT scan. In extreme cases, such as when metal objects are present in the sample, more severe artefacts occur at the location of the metallic components. Also when the X-ray photon do not succeed to get through the metal (photon starvation), incorrect representation of the sample occurs in the reconstructed data.