Reducing the influence of environmental scattering in industrial computed tomography by system modifications and correction algorithms

High energetic X-ray photons are scattered in both the object and the system’s components and cause artefacts in industrial computed tomography (CT). In this contribution, we investigate the influence of individual CT components on environmental scattering by experimentally verified Monte Carlo simulations. An assessment of different configurations indicates a potential reduction in environmental scattering by 81 ± 4 % due to system modifications. The contribution of environmental scattering to the transmission signal displays only a weak spatial variation. Thus, an analytical correction method is suggested, which is applied on the transmission images prior to reconstruction. This procedure requires a single input parameter and is applied on measurements of an industrial CT system operating a source with 450 kV maximum acceleration voltage. The suggested procedure increases the contrast of the central hole in an aluminium step cylinder with a diameter larger than 160 mm by more than a factor of 2.4 compared to non-corrected data.