error in TOF results

General Discussions
1

Dear CASToR users

I used the castor3.0.1 to reconstruct a PET data of some cylindrical phantoms and I used different TOF_reso values and also non TOF case. But I found that the SNR value of the non TOF was bigger than the TOF cases of 400,300,200 ps ( with decreasing the TOF value the SNR decreased) . Should I modify the TOF command in Cdh file to apply the TOF on the image quality? Did anyone face this issue?

Thank you so much.
Hadi

2

Dear Hadi,

Are you using the same dataset for your different reconstructions ?

Simon

3

Hi Simon
Thank you for your reply
Yes, I used the same dataset for all reconstructions.
Best regards
Hadi

4

Hi Hadi,

Do you mean that you simulated PET data with different scanner TOF resolutions, and then tried to reconstruct the data with the corresponding TOF resolution?

I don’t understand your question about TOF command, could you reformulate please?

5

Sorry I didn’t see the previous message. If you use a wrong TOF resolution in the reconstruction, different from the nominal TOF resolution of the scanner, it is normal that you get issues in the reconstruction.

6

Hi Marina
I am sorry if my message is not clarified. I simulated a PET data at one time ( I didn’t change the PET scanner) but I reconstructed this data with different TOF values.
Best
Hadi

7

also I used this command: “./castor-GATERootToCastor -i myroot.root -m mymac.mac -o output300 -s output300 -geo -k -TOF_reso 300”
Best regards
Hadi