The recon results

Hi, Dear Castor users,
i met a confusion about CASTOR results.
i created two GATE simulations, with phantom and several different radioactive sources, the difference is the material of phantom , one is air (little attenuation and scatter) and the other one is water, (as described in attachment .mac files ). I chose TRUE events both from these two simulations separately, but what was surprised after CASToR recon was that, only the air phantom recon image was right , and the water phantom’s was so strange. i checked the true events, and did not find anything weird, so i did not know the reason , is there something wrong?
regards,

myIEC_air.mac (12.6 KB)

myIEC_water.mac (12.6 KB)

run_castor_recon_unix.sh (6.46 KB)

run_GATERootToCastor.sh (634 Bytes)

Hi,

Would you have an image of what is right and what is strange, or a description ?
Otherwise, it will be difficult to find some clue.

Best
Simon

Hi,Simom

I’m sorry about that. Here are some image pictures in attachments.

At first, i thoutht that maybe scatter events were terrible, so i chose True evnets for GATE .root file, and with option “-isrc xxxx” in GATERootToCastor excutable to get the source image of simu, there was not so bad as recons.

1.JPG : left ,Air phantom true events source image from GATE simulation; right : the CASToR recon image of it ;

2.JPG : left ,Water phantom true events source image from GATE simulation; right : the CASToR recon image of it;

3.JPG : left, Air phantom true events source image from GATE simulation​ ; right: Water phantom true events source image from GATE simulation​

4.JPG : left, Air phantom Recon results, right: ​Water phantom Recon results,​

regards,

Nothing really strange to me.

Seeing your image with the air phantom, I think that your reconstruction setup is fine.

So it looks like the effect of attenuation correction that is not applied during reconstruction.

Try to correct for it and see.

Simon