Dear Castor users,
I am trying to reconstruct simulated data of SPECT system of two heads. During the reconstruction process, I observe:
- with low-statistics data the reconstructed images appear as expected.
- with higher-statistics data with the same reconstruction parameters, a ring artifact appears in some of the phantom’s organs, as shown in the attached images.
We are to investigate the effect of PSF parameters, but any suggestions would be greatly appreciated.
Data parameters:
- projections with 5deg step (30sec/projection)
- Detector’s pitch size : 1.7mm
Reconstruction command:
./castor-recon -df /path/to/mouse_high_stats_df.Cdh -fout /path/to/high_stats -dim 99,150,197 -vox 0.5,0.5,0.5 -opti MLEM -it 1:10 -conv gaussian,2,2,3::psf
Many thanks in advance!
Best
Giorgos
