CASToR Reconstruction for SPECT

hello everyone…
I am working with CASToR (RootToCastor) and imageJ/AMIDE to reconstruct my SPCT-output but i have not get the good image. i mean the result of CASToR is empty / dark ! I even use NucMed plugin on imageJ but there is no result/ picture …!
I would appreciate if anyone help me to get image … :pray: :cherry_blossom:

Hi Sahar,
It is complicated to answer without having details about the simulation or the reconstruction parameters as errors could occur for different reasons. Could you share details about it ? (what is the SPECT system/collimator and object used for the simulation, which command line did you use for the conversion/reconstruction, what are the values in the reconstructed image (0, NaN) ? )
Best,
Thibaut

Hi Thibaut,
thanks you for answering. sure! I will tell you what exactly i use… It is simulation of SPECT with LEAP Collimator and Jaszczak phantom.
the command line i uesed :
./castor-GATERootToCastor -i /home/sahar/GATE/spect_results.root -o /home/sahar/GATE/output -m /home/sahar/GATE/MainSPECT.mac -s SPECThead -sp_bins 256,512
&
./castor-recon -df /home/sahar/GATE/output_df.Cdh -opti MLEM -it 1:16 -proj joseph -conv gaussian,4.,4.5,3.5::psf -dim 256,512,1 -vox 2.5,4.,1. -dout my-images

after all this , i did not face any error and after this commands i got some files (my-image.log & my-image_it1.hdr & my-image_it1.img) and when i use imageJ or AMIDE to see the image, the final image is dark which i attach it below:

thanks you…
Sahar

Hi,

Try to open your image using real 32bits type and look again if it is still dark.

Simon

Hi Simon,
thanks you. i tried it as you say but it is still dark … :frowning:
is there any way ?!
best regard
sahar

Nothing appears wrong from the command lines.
What are the values in the “dark” image ? 0, Nan or very low values ?
Maybe you could send the root & mac files so that I have a look.

Of course , I would appreciate if you give me your email address to send them …
thanks a million…

Hi Thibaut,
it is just a reminder message… I would thanks you if you give me your email address to send you the root & mac files…
best regard
sahar

Hi Sahar,
The issue comes from your simulation. There is no data in the Singles branch of your root file, as you can see if you inspect the root file. You can also check the CASToR conversion log file which reports the number of singles which have been converted.

Note that your SinglesAdder branch contains data, so most likely there is something wrong in your digitizer setup.

Best regards

Hi Thibaut ,

I received your message. that was good point that I had missed it! I will definitely check. Thank you very much for your help.

Best wishes…

Sahar

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Hi dear Thibaut,

First, I want to thank you for helping me… secondly ,I made some changes on my mac file and I have data on the Singles branch of my root file now but still the image reconstructed is dark! I checked my log file with the example of castor for SPECT, everything is the same as example and i don’t know what’s the problem… I would greatly appreciate if you have any other suggestion…

wish you the best weekend!

Sahar

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Hi Sahar,
According to your recon command line, you are only reconstructing the central slice (-dim 256,512,1).
However your phantom is translated 34mm on the z-axis in your mac file, so you are reconstructing an area outside your object, hence the empty image.
Best,
Thibaut