In 1991 IEEE Nuclear Science Symposium and Medical Imaging Conference Record, volume 3, pages 1758-1762, Santa Fe, New Mexico, 5-9 November 1991.
A major problem in SPECT imaging is noise due to the small number of detected photons emitted from a feature of interest. We have investigated the effects of simultaneously using both parallel and converging collimation to enhance the sensitivity in a central field of view, while adequately sampling the entire object. The sensitivity effects of several collimator combinations were simulated for several total count rates, with and without constant uniform attenuation. Our results show that using one parallel collimator and five converging collimators, the central region has a contrast to noise ratio equivalent to using twice the counts with only parallel collimation.