[Gate-users] problem for Cubic voxelized source: Voxel reader (???)

Qiyong Fan fanqy05 at gmail.com
Thu Apr 28 16:24:05 CEST 2011


Dear Sheen

There are at least two problems.1. If 0 voxels are read in, it means GATE
did not successfully load in your phantom. Please check examples. 2. your
translator does not make sense. Look at what G4 says:


[G4]    Range   0 : imageValue in [    9.830e+02 , 9.830e+02 ]  --->
activity (Bq) 1.000e-02
[G4]    Range   1 : imageValue in [    9.830e+02 , 9.830e+02 ]  --->
activity (Bq) 0.000e+00


There are two ranges specified in your translator. Range 0 lets GATE
translate image value 9.83e02 to 9.83e02 to 1.000e-02 Bq, Range 1 lets GATE
translate the same image value into 0 Bq. Therefore even if GATE loads in
your phantom correctly, you will get zero Bq.


On Thu, Apr 28, 2011 at 6:00 AM, <
gate-users-request at lists.opengatecollaboration.org> wrote:

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> Today's Topics:
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>   1. Several questions about the ASCII data output (Qiyong Fan)
>   2. Re: Several questions about the ASCII data output
>      (Jean-Baptiste Michaud)
>   3. problem for Cubic voxelized source: Voxel reader (???)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 27 Apr 2011 11:02:42 -0400
> From: Qiyong Fan <fanqy05 at gmail.com>
> To: gate-users at lists.opengatecollaboration.org
> Subject: [Gate-users] Several questions about the ASCII data output
> Message-ID: <BANLkTinkVK8hRGoe-gi_6TL3DSaKFr=Nfg at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Dear Gate users,
>
> I am using GATE V5 to do a PET experiment with ASCII data output. I have
> several questions,
>
>
> 1. In the output coincidence file "gateCoincidences.dat", the user guide
> says for column 22 and 23,
>
>   - Column 22 : Scanner axial position (first single)
>   - Column 23 : Scanner angular position (first single)
>
> What exactly does gate mean by "scanner axial position and angular
> position"? I got all of them to be 0.000e+00 for all coincidence counts.
> Just do not know why.
>
> 2. Also, the second column is the "ID of the event". What does "event" mean
> here? Does it just mean coincidence event? Therefore, true coincidence
> event
> should have the same event ID?
>
> Thanks,
>
> Qiyong Fan
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 27 Apr 2011 14:11:00 -0400
> From: Jean-Baptiste Michaud <jbmichaud at videotron.ca>
> To: 'Qiyong Fan' <fanqy05 at gmail.com>
> Cc: gate-users at lists.opengatecollaboration.org
> Subject: Re: [Gate-users] Several questions about the ASCII data
>        output
> Message-ID: <003a01cc0506$76cc60b0$64652210$@ca>
> Content-Type: text/plain; charset=us-ascii
>
> Dear Fan,
>
> Axial and angular position: you have to include commands to change the
> position of the object relative to the scanner DURING acquisition in order
> for those values to change. They are used to simulate bed, gantry or object
> movements. The columns that you do not need can be disabled in the output
> using the output mask.
>
> Event ID: a unique disintegration (or back-to-back emission). So yes, trues
> will have the same event ID.
>
> Regards
>
> jb
>
> -----Original Message-----
> From: gate-users-bounces at lists.opengatecollaboration.org
> [mailto:gate-users-bounces at lists.opengatecollaboration.org] On Behalf Of
> Qiyong Fan
> Sent: April 27, 2011 11:03
> To: gate-users at lists.opengatecollaboration.org
> Subject: [Gate-users] Several questions about the ASCII data output
>
> Dear Gate users,
>
> I am using GATE V5 to do a PET experiment with ASCII data output. I have
> several questions,
>
>
> 1. In the output coincidence file "gateCoincidences.dat", the user guide
> says for column 22 and 23,
>
>   - Column 22 : Scanner axial position (first single)
>   - Column 23 : Scanner angular position (first single)
>
> What exactly does gate mean by "scanner axial position and angular
> position"? I got all of them to be 0.000e+00 for all coincidence counts.
> Just do not know why.
>
> 2. Also, the second column is the "ID of the event". What does "event" mean
> here? Does it just mean coincidence event? Therefore, true coincidence
> event
> should have the same event ID?
>
> Thanks,
>
> Qiyong Fan
> _______________________________________________
> Gate-users mailing list
> Gate-users at lists.opengatecollaboration.org
> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>
>
>
> ------------------------------
>
> Message: 3
> Date: Thu, 28 Apr 2011 06:58:13 +0900
> From: ??? <msk0567 at gmail.com>
> To: Gate-users at lists.opengatecollaboration.org
> Subject: [Gate-users] problem for Cubic voxelized source: Voxel reader
> Message-ID: <BANLkTi=qLEFaykFzadryVsEGojnw-V2Qxw at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Dear all,
>
> I am trying NCAT phantom in GATE.
> I used example_TimeActivityCurve for it.
>
> I could visualize a voxellized phantom.f
> However, it cannot be emitted gamma ray.
> I suppose that I have some problem for Cubic voxelized source as
> followineesoon.g:
> [*G4]   Voxel reader ---------->   number of voxels       : 0
> *The number of voxels is 'zero', so it causes for this.
>
> I do not know what I can fix.
> Please any advice.
>
>
> With best regard,
> Heesoon Sheen
>
>
>
>  ===== EM models for the G4Region  DefaultRegionForTheWorld ======
> [G4]                eBrem :     Emin=  0.000e+00 eV         Emax=   1.0e+00
> GeV
> [G4]             eBremRel :     Emin=  1.000e+00 GeV        Emax=
> 1.000e+02 TeV
> [G4]  The Object RTVPhantom is attached to the interfileReader Source Voxel
> Reader.
> [G4]  Header read from       'data/DtestHeart_atn_1.h33'
> [G4]  Data file name         'data/DtestHeart_act_1.bin'
> [G4]  Nb of planes:           64
> [G4]  Nb of pixels per plane: 128 128
> [G4]  Pixel size:             6.250e+00 6.250e+00
> [G4]  Slice thickness:        6.250e+00
> [G4]  Matrix size:            8.000e+02 8.000e+02
> [G4]  Data type:              UNSIGNED INTEGER
> [G4]
> [G4]   Voxel reader ---------->   number of voxels       : 0
> [G4]   total activity (Bq)    : 0.000e+00
> [G4]   position  (mm)         : 0.000e+00 0.000e+00 0.000e+00
> [G4]   voxel size  (mm)    : 6.250e+00 6.250e+00 6.250e+00
> [G4] GateVSourceVoxelReader::UpdateActivities(G4String, G4String) Time is
> 0.000e+00  cK = 1   p_cK = 0
> [G4] 0 x 0.000e+00  y 1.000e-02
> [G4] 1 x 2.000e+00  y 7.000e+00
> [G4] 2 x 4.000e+00  y 1.000e+00
> [G4]  current time 0.000e+00 current activity 1.000e-02
> [G4] activity range 9.830e+02  9.830e+02    iRange range1 range2 0
> 9.830e+02
> 9.830e+02
> [G4]    Description of Range Translator
> [G4]  Range Translator
> [G4]    Range   0 : imageValue in [    9.830e+02 , 9.830e+02 ]  --->
> activity (Bq) 1.000e-02
> [G4]    Range   1 : imageValue in [    9.830e+02 , 9.830e+02 ]  --->
> activity (Bq) 0.000e+00
> [G4]  The Object RTVPhantom is attached to the interfileReader Source Voxel
> Reader.
> [G4]  Header read from       'data/DtestHeart_atn_1.h33'
> [G4]  Data file name         'data/DtestHeart_act_1.bin'
> [G4]  Nb of planes:           64
> [G4]  Nb of pixels per plane: 128 128
> [G4]  Pixel size:             6.250e+00 6.250e+00
> [G4]  Slice thickness:        6.250e+00
> [G4]  Matrix size:            8.000e+02 8.000e+02
> [G4]  Data type:              UNSIGNED INTEGER
> [G4]
> [*G4]   Voxel reader ---------->   number of voxels       : 0*
> [G4]   total activity (Bq)    : 0.000e+00
> [G4]   position  (mm)         : 0.000e+00 0.000e+00 0.000e+00
> [G4]   voxel size  (mm)    : 6.250e+00 6.250e+00 6.250e+00
> [Core-0] End of macro mainMacro.mac
>
>
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> End of Gate-users Digest, Vol 59, Issue 27
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