[Gate-users] No coincidences when using generic repeater in PET

[Christian Pommranz]

Dear Zhengzhi and Han,

thank you Han for your quick reply and the How-To slides! It's great to
hear that the patch worked for you!

This patch is indeed (by design) not working for combinations of the
generic repeater and the angular repeater for the same component. The
code only looks at the generic repeater's repeat number if no angular
repeater was found, i.e. "rep_num == 1" for the angular repeater. The
generic repeater patch uses the angular repeater "mechanism" to compute
sectorIDs and one repeater would therefore (probably) interfere with
the other. Since I implement my geometries with the generic repeater
only, I didn't try to generalize the sectorID computation, yet.

The relevant code is in the "G4int
GateCoincidenceSorter::ComputeSectorID(const GatePulse& pulse)" method
in the "GateCoincidenceSorter.cc" file.

I will rebase the patch to the current develop branch and create a PR
as soon as I find the time.

Best regards,
Christian


Am Montag, den 27.01.2020, 23:36 -0800 schrieb Zhengzhi Liu:
> Dear Han Gyu and Christian, 
> 
> Thanks, Han Gyu very much for your quick response and Christian great
> contribution. I just installed the patch and the installation
> went well,  then I reboot my vGATE8.2 virtual machine. However, I
> still didn't get any coincidence event registered when
> using genericRepeater in a cylindricalPET system in my simple test. 
> 
> Here is what I did: 
> I replaced the ring repeater with genericRepeater
> in benchPET, reduced the number of detector heads to 2 and set
> minSectorDifference to 1. Then I did a visualization check.
> Finally, I got no coincidence recorded. Then I switched back to ring
> repeater (which is the only change for this step), I did collect many
> coincidence events. So it looks the patch doesn't fix the problem
> in cylindricalPET. 
> 
> Has anyone ever got the patch work in a cylindricalPET system? 
> 
> Thank you so much, dear GATE community members.
> Sincere greetings,
> 
> Zhengzhi 
> 
> 
> 
> On Mon, Jan 27, 2020 at 8:27 PM 강한규 <lovehangulp at naver.com> wrote:
> > Dear Zhengzhi, and Christian,
> > 
> >  
> > 
> > As you already know, Christian (pommranz at astro.uni-tuebingen.de)
> > shared the git patch file to solve the coincidence output issue. 
> > 
> > http://lists.opengatecollaboration.org/pipermail/gate-users/2019-February/010729.html
> > 
> >  
> > 
> > I have also succeeded in acquiring coincidence output using generic
> > repeater in PETscanner system with the patch file shared by
> > Christian.
> > 
> > Below is an example of the detector arrangement with
> > genericRepeater.
> > 
> > Thanks Christian for your great contribution~!
> > 
> >  
> > 
> >   
> > 
> > Here is a brief manual how to apply the git patch in GATEv8.2.
> > 
> > ===================================================================
> > ========================================================
> > 
> > Problem: No coincidence in the "PETscanner"
> > when genericRepeater was used.
> > Solution: Modify the GATEv8.2 source code using a git patch
> > file and re-compile.
> >  
> > GATE mailing list (Christian Pommranz <
> > pommranz at astro.uni-tuebingen.de>) 
> > http://lists.opengatecollaboration.org/pipermail/gate-users/2019-February/010729.html
> >  
> > STEP1> Download the git patch file in the mailing list.
> > Filename: coincidences_for_generic_repeater.patch
> >  
> > STEP2> Apply the git patch file.
> > >cd /home/kanghg2/program/Gate-8.2
> > >git apply --ignore-space-change --ignore-whitespace
> > coincidences_for_generic_repeater.patch
> >  
> > STEP3> Re-compile GATEv8.2
> > >cd /home/kanghg2/program/Gate-8.2-build
> > >ccmake ../Gate-8.2
> > [c] configure
> > [g] generate
> >  
> > >make
> >  
> > STEP4> Run the GATE PETscanner with genericRepeater.
> > Now coincidence output will be generated!
> > ===================================================================
> > ========================================================
> > 
> >  
> > 
> > Hopefully, you will be able to obtain coincidence output with
> > genericRepeater. 
> > 
> >  
> > Best regards,
> > 
> >  
> > 
> > Han Gyu Kang, Ph.D.
> > 
> >  
> > 
> > Imaging Physics Group, NIRS-QST, Japan.
> > 
> > -----Original Message-----
> > From: "Zhengzhi Liu"<zliu36 at stanford.edu> 
> > To: <gate-users at lists.opengatecollaboration.org>; 
> > Cc: 
> > Sent: 2020-01-28 (화) 12:47:21 (GMT+09:00)
> > Subject: [Gate-users] No coincidences when using generic repeater
> > in PET
> >  
> > 
> > Dear GATE community members, 
> >  
> > I looked at previous GATE correspondence, it looks there has been
> > an issue with coincidence sorter when using along with generic
> > repeater. I am using vGATE8.2, it still exists. 
> >  
> > Has anyone ever succeeded in getting them to work together? 
> >  
> > Thanks a lot for your advice.
> > Sincerely,
> >  
> > Zhengzhi 
-- 
Christian Pommranz

Institute for Astronomy and Astrophysics
Kepler Center for Astro and Particle Physics
Eberhard Karls University Tübingen
Sand 1
D-72076 Tübingen
Germany

Phone: +49 7071 29 75463
http://www.uni-tuebingen.de/index.php?id=3130