Hello CASToR Users,
I’ve been using CASToR to reconstruct images of various human PET scanners to compare their image quality. So far, through working with CASToR, I learned that the quality of the reconstructed images for any PET scanner significantly varies when changing the image convolver’s FWHM.
For example, the attached file shows images of a Derenzo-like phantom obtained from simulations of a brain-dedicated PET scanner and reconstructed with CASToR using listmode EM reconstruction. This arbitrary PET scanner had LSO detectors with a crystal width of 2 x 2 mm^2 and a crystal depth of 20 mm. In (A), images were reconstructed using “-conv gaussian,2,2,3::psf” and in (B), the same listmode data were reconstructed using the same reconstruction parameters but with convolution parameters of “-conv gaussian,1,1,3::psf”.
How legitimate does this sound to say that “for a PET scanner, the convolver’s FWHM should be equal to the scanner’s crystal width”? In general, are there any recommendations as to how image convolver’s parameters should be chosen for any arbitrary PET scanner?
Thank you for your responses,