[Castor-users] Problem on Reconstruction from GATE root output
tmerlin
Thibaut.Merlin at univ-brest.fr
Fri Sep 8 20:53:53 CEST 2017
Hello Ying-yu,
For your questions:
Q1: Yes, the -t option only converts true unscattered events and there
is no current option to keep only trues and scatters. However you could
make some small changes in the file
/toolkits/castor-GATERootToCastor.cc/ in order to recover both trues and
scatters:
Around line 1492, replace:
/if (true_only_flag==true && kind != KIND_TRUE)/
by
/if (true_only_flag==true && kind != KIND_TRUE && ///kind != KIND_SCAT
/////&& ///kind != KIND_MSCAT/// ) /
and around line 1646, replace:
/ Out_data_file->SetNbEvents( (true_only_flag) ?//nLORs_trues ://
nLORs_tot ) ;/
by
/ Out_data_file->SetNbEvents( (true_only_flag) ?////nLORs_trues
/+/nLORs_scatters ://nLORs_tot ) ;/
/
/then recompile. Then the datafile should include scatters as well./
/
/
/
Q2://Maximum ring difference set to -1 just mean there is no restriction
regarding the ring difference. So it will be equal to 51 in your case./
/
/
/
Q3://I am not sure what is wrong in the reconstructed images. The
positions of the sphere sources in the image are not correct ?/
/
/
/
Best regards,
Thibaut/
/
/
/
/
/
On 07/09/2017 10:00, Ying-yu Chen wrote:
> Dear CASToR users,
>
> I'm trying to build an PET simulation using the GATE ecat system. The
> Geometry macro "Geometry.mac" is attached for reference.
>
> I first simulated two 2.5mm-radius sphere sources in a phantom.From
> raw sinogram, I think I can see the two sphere sources. Root datafile
> and raw sinogram could be downloaded through the following link.
> https://drive.google.com/open?id=0B0vKwnYlHgr1LWpiclpnTUFZbUE
>
> I converted the GATE geometry to the .geom file ("GATE_PET.geom" as
> attached) and then converted root datafile to CASToR datafile with -t
> option. ("aq4.log", "aq4_CstrProj.Cdh" and "aq4_CstrProj.Cdf" as attached)
>
> Q1: It seems that the -t option only converts true unscattered events.
> Is it able to convert true unscattered and scattered events (no random)?
>
> Q2: In aq4_CstrProj.Cdh, the maximum ring difference is -1. Since the
> simulated PET has 52 detector rings, I think the maximum ring
> difference should be 51. I would like to know why is it -1?
>
> Then I use the following command to perform the reconstruction.
>
> castor-recon -df aq4_CstrProj.Cdh -dout recon_aq4 -it 3:8 -dim
> 400,400,109 -fov 780,780,218
>
>
> Q3: The reconstructed images are not right. Is there any idea how I
> can solve it?
> https://drive.google.com/open?id=0B0vKwnYlHgr1V3F2Q2JTLTlyc00
>
> Thank you very much and I'm looking forward to hearing from you.
>
> Your sincerely,
> Ying-Yu Chen
>
>
>
>
> _______________________________________________
> Castor-users mailing list
> Castor-users at lists.castor-project.org
> http://lists.castor-project.org/listinfo/castor-users
--
Thibaut MERLIN -- PhD
Docteur en Imagerie Médicale au Laboratoire de Traitement de l'Information Medicale (LaTIM - INSERM UMR 1101)
Bâtiment 1
CHRU Morvan - 2, Av. Foch
29609 Brest CEDEX - FRANCE
Tel: 06.75.12.24.90
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