Fig. 6

PSNR for the SPECT image and corresponding smoothed template as a function of the FWHM of the Gaussian filter used to smooth the template. The maximum PSNR identifies the most optimal FWHM value for the template to match the SPECT image resolution. On the left axis, the PSNR for a 6 min 3D CZT Veriton SPECT scan reconstructed with 6 iterations, 12 subsets and 3 mm FWHM Gaussian post-smoothing and on the right axis, the PSNR for the conventional 16 min Siemens Symbia SPECT scan reconstructed with 16 iterations, 16 subsets and 1 mm FWHM Gaussian post-smoothing