Analytical correction methods for aperture and attenuation effect in SPECT

This paper describes the performance of analytical correction method for collimator aperture and attenuation of gamma rays in single photon emission CT. The attenuation correction method used was Kudo's method and the aperture correction method used was Lewitt's method. The performance was evaluated various aperture angles, rotation distances of a detector and the number of projections used for image reconstruction. The simulation results showed that the performance of aperture correction was good for small aperture angle, i.e. less than 1 degree and the aperture correction method greatly enhanced noise component in measured projections. (author)