Contrast noise behaviour of a rotating slat collimated gamma camera

Compared to classical parallel hole (PH) collimated gamma cameras, the geometry of a rotating slat (RS) collimated detector implies a better sensitivity versus resolution trade-off. Nevertheless, the expected improvement in image quality from this device is degraded due to the assumptions made during the image reconstruction of planar images. This study shows that an accurate model of the imaging process for iterative reconstruction is necessary in order to improve planar image quality. To this end, a Monte Carlo based system matrix was derived from a simple simulation by exploiting the rotational and translational symmetries present in this acquisition set-up. It was found that this system matrix improves the contrast and noise characteristics of reconstructed images compared to a reconstruction with no modelling. As a result, the RS device is able to yield improved quality for planar images compared to a PH camera.