[Gate-users] Re: FW: Difference in energy spectrum for first and second event in cylindrical PET system

[Irène Buvat]

>Hi Paul and Yuxuan,
>
>Following your suggestions, I took a closer look at the energy histogram
>of the delayed coincidences by looking at the delays.dat output file.
>As Paul said, the order of the singles in a random coincidence is always
>that the early single is the first half and single 2 (the later one) is
>always the second half.  In the delays file, the two singles should be,
>by definition, just singles and thus they should exhibit an identical
>energy spectrum.  This is not what I see when I look at the data (see
>attached energy histogram).  In my data, single 1 has a different energy
>spectrum than single 2.  The only real difference between the two
>singles is that single 1 is 1 microsecond earlier than single 2.  I have
>no idea why the two singles in the delays file should have different
>spectra, so any additional insight you could offer into this would be
>appreciated.
>
>Cheers,
>Andrew
>
>Andrew Goertzen
>Department of Radiology
>University of Manitoba
>
>
>
>
>
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>Attachment converted: Macintosh HD:DelaysEnergyHistogram.jpg 
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-- 
Irene Buvat, PhD
Equipe "Imagerie de la perfusion et des échanges moléculaires"
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