Monte Carlo characterization of scattered radiation profile in volumetric 64 slice CT using GATE

Abstract

It is well known that contamination of CT data with scattered radiation reduces reconstructed CT numbers and introduces cupping artifacts in the reconstructed images. This effect is more pronounced in multi detector CT scanners with extended detector aperture mostly using cone-beam configurations, which are much less immune to scatter than fan-beam and single-slice CT scanners. Accurate characterization of scattered radiation behavior is mandatory for implementation of robust and accurate scatter correction strategies in volumetric CT reconstruction. As characterization of scattered radiation behavior using experimental measurement is a difficult and time consuming approach, Monte Carlo simulation can be an ideal calculation method. In this study we used recently released GATE MC Code with the ability of CT simulation for characterization of scattering in volumetric GE 64 slice CT scanner. The Monte Carlo simulation was validated through comparison with experimental measurement data. Thereafter, the effect of tube voltage and Scatter to Primary Ratio (SPR) was calculated. The results indicate that the GATE Monte Carlo code is a useful tool for investigation of scattered radiation characterization in CT scanners. Moreover, there is a possibility of take advantage of GATE for simulation of PET scanners in order to simultaneously asses the contribution of scattered radiation in PET/CT scanners. © 2011 Springer-Verlag.