[Castor-users] PET reconstruction from a binary LUT file

[Simon Stute]

Hi,

Yes, the order as (*2) is assumed: castorID = iDet + iRing*NDet + 
iLayer*NRing*NDet;

This ordering is only used to get the crystal dimensions as specified 
per layer in the header file of the scanner description (to compute the 
correct depth position in the crystal).
So that if the crystal IDs you write in the datafile to be reconstructed 
are in agreement with the order of the crystal positions you wrote in 
the LUT file, the reconstruction should be fine.

As you get a correct sensitivity map, this means that IDs written in the 
datafile are likely not correct.

Also to be sure, here in your email, I assume that NDet is the number of 
detectors inside a single ring, not for all the layer. Whereas in the 
header of the LUT file, this is the total number of crystals per layer 
which should be provided.

Best
Simon


Le 25/07/2018 à 16:58, Daiki HAYAKAWA a écrit :
> Dear CASToR users,
>
> We are trying to reconstruct PET image from a binary LUT file 
> following the page 21 in the general document. The sensitivity map 
> looks fine but reconstructed images make no sense. We think that there 
> would be a problem regarding to castor ID for each detector (but we 
> are not fully sure).
> We currently create a binary LUT file as the for loops (*1) suggested 
> in the document. Does the castor ID for detectors follow the order 
> like (*2)?
>
> Any suggestions/comments are welcome.
>
> Thank you and kind regrads,
> Daiki Hayakawa
>
>
> (*1)
> for(iLayer=0;iLayer<NLayer;iLayer++)
>     for(iRing=0;iRing<NRing;iRing++)
> for(iDet=0;iDet<NDet;iDet++) {
> fwrite(&Posx[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> fwrite(&Posy[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> fwrite(&Posz[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> fwrite(&OrVx[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> fwrite(&OrVy[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> fwrite(&OrVz[iLayer][iRing][iDet],sizeof(FLTNBLUT),1,fPtr);
> }
>
> (*2)
> for(iLayer=0;iLayer<NLayer;iLayer++)
>     for(iRing=0;iRing<NRing;iRing++)
> for(iDet=0;iDet<NDet;iDet++) {
> castorID = iDet + iRing*NDet + l*NRing*NDet;
> }
>
> ------------------------------------------------------
> Daiki HAYAKAWA
> Group: TT-PET
> DPNC, University of Geneva
> E-mail: daiki.hayakawa at cern.ch <mailto:daiki.hayakawa at cern.ch> , 
> Daiki.Hayakawa at unige.ch <mailto:Daiki.Hayakawa at unige.ch>
> ------------------------------------------------------
>
>
>
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