A novel approach for experimental measurement of scatter profile and scatter to primary ratio in 64-slice CT scanner

Abstract

Scattered radiation is an important source of artifacts in x-ray CT imaging and its detrimental effects have become much stronger in 64-slice CT scanners with extended detector aperture. The magnitude and spatial distribution of the scatter component should be corrected for before or during the reconstruction process. Thorough knowledge of scatter distribution is essential for development of scatter correction algorithms. In this study a novel approach based on using dedicated blockers is proposed to efficiently calculate scatter profiles and scatter to primary ratio (SPR) in different detector rows in a CT scanner with 64-slice capability. The influence of different parameters such as tube voltage, phantom size and phantom off-centering on the scatter profile and SPR was quantitatively measured based on the developed method. The SPR decreases from 219.9 to 39.9 when the tube voltage increases from 80 kVp to 140 kVp in 21.5 cm water phantom. The proposed method is easy to use and straightforward and can be used for any measurement. © 2008 Springer-Verlag.