[Gate-users] No comptonPhantom or RayleighPhantom entries for voxelized phantom

[Tom Buitenhuis]

Dear GATE users,

I am having the same problem as Yannick Berker described on 2011-10-21. I use the ImageNestedParametrisedVolume phantom for a PET simulation. The sources are described using interfiles. Everything seems to be working correctly, i.e. the sources and phantom are in the right place and coincidences are detected. The effect of phantom attenuation is also clearly visible.

The problem that I’m having, is that in the ROOT coincidences tree there is no comptonPhantom and RayleighPhantom data. I cannot add the VoxelPhantomSD to the ImageNestedParametrisedVolume, because I get an error message saying the command is unavailable. I can add the ordinary PhantomSD, but this does not seem to add the comptonPhantom or RayleighPhantom information to the coincidence tree. The comptonCrystal and RayleighCrystal entries are correct, so I think the physics processes are registered and working correctly. 

I need the comptonPhantom and RayleighPhantom information to get scatter information on coincidences.

Did anyone else come across this problem, and if so, how did you solve it? Or can anyone point me in the direction of a solution?

Regards,

Tom Buitenhuis

PhD student
KVI - Center for Advanced Radiation Technology
University of Groningen
The Netherlands

> Dear GATE users,
> 
> I have some issues using the HounsfieldMaterialGenerator to simulate a PET scan of a patient. The
> simulation itself is running fine, but I am lacking two features that I am used to from other simulations,
> which are scatter information and color visualization. I mainly used the example from
> http://www.creatis.insa-lyon.fr/gate/Example2/ to generate the following phantom:
> 
> /gate/HounsfieldMaterialGenerator/SetMaterialTable                  CT/Schneider2000MaterialsTable.txt
> /gate/HounsfieldMaterialGenerator/SetDensityTable                   CT/Schneider2000DensitiesTable.txt
> /gate/HounsfieldMaterialGenerator/SetDensityTolerance               0.03 g/cm3
> /gate/HounsfieldMaterialGenerator/SetOutputMaterialDatabaseFilename CT/p971-HUmaterials.db
> /gate/HounsfieldMaterialGenerator/SetOutputHUMaterialFilename       CT/p971-HU2mat.txt
> /gate/HounsfieldMaterialGenerator/Generate
> /gate/world/daughters/name                                          patient
> /gate/world/daughters/insert                                        ImageRegionalizedVolume
> /gate/geometry/setMaterialDatabase                                  CT/p971-HUmaterials.db
> /gate/patient/geometry/SetHUToMaterialFile                          CT/p971-HU2mat.txt
> /gate/patient/geometry/SetImage                                     CT/p971s3.hdr
> ...
> 
> The ROOT output shows me that the volume is placed correctly, and the distribution of detected
> coincidences also shows the effect of photon attenuation by the phantom. However, I cannot attach a
> VoxelPhantomSD to the patient - I receive an error message telling me that this command is unavailable:
> [G4-cerr] ***** COMMAND NOT FOUND </gate/patient/attachVoxelPhantomSD> *****
> Attaching an ordinary PhantomSD seems to work, but only generates 0 entries in ComptonPhantom and
> RayleighPhantom. I also tried using a ImageNestedParametrisedVolume, with no effect. ComptonCrystal
> entries, however, seem to be correct (>= 0).
> 
> Apart from that, how can I visualize the voxelized phantom using colors? I was not able to add color
> attributes (like "true 0.5 0.5 0.5 1.0") to p971-HU2mat.txt manually, since this resulted in the
> following error message:
> src/GateVImageVolume.cc (l.332): No Hounsfield material defined in the file
> CT/p971s3_ToSim_OneBP_HU2mat_Colors.txt. Abort
> 
> Does anyone have knowledge in this area, or can point to some helpful documentation on this topic? The GATE
> User's Guide has a few, but only incomplete examples for the case of voxelized phantoms and sources.
> 
> Best regards,
> 
> Yannick Berker
> 
> The information contained in this message may be confidential and legally protected under applicable
> law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are
> hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly
> prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return
> e-mail and destroy all copies of the original message.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/mailman/private/gate-users/attachments/20140306/0387a69a/attachment.html>