[Gate-users] Detector inside voxelized phantom

[Francisco Pinto]

Hi David,

Thank you so much for your reply! After replacing my ImageParametrizedRegularVolume with an ImageRegionalizedVolume (+ distance maps) & making my SPECTHead a daughter of my voxelised phantom. I am getting a crash, which I’ve narrowed down to GateCrystalSD::FindSystem(G4String&) – voxPhantom cannot be found.

I am at a loss here, do you perhaps have further input?

Thanks once more!
Francisco

From: David Sarrut [mailto:David.Sarrut at creatis.insa-lyon.fr]
Sent: 25 August 2016 09:37
To: Francisco Pinto <francisco.pinto at surgiceye.com>
Cc: gate-users at lists.opengatecollaboration.org; Philipp Matthies <Philipp.Matthies at surgiceye.com>
Subject: Re: [Gate-users] Detector inside voxelized phantom

Hello,

in short : this is a known limitation, you cannot do that.

Indeed volumes cannot be overlapped (it is a G4 requirement). So if you insert a volume A (detector) within the bounds of a volume B (voxel), A must be child of B, and in this case the part of B within the A volume is not seen.

Possible workarounds : reduce the size of B so that A is outside or create A as voxels part of B.

I think that some groups (Brest) are currently working on an implementation of hybrid volumes that could allow such situation. I think it is not yet finished.

David


On Wed, Aug 24, 2016 at 9:15 PM, Francisco Pinto <francisco.pinto at surgiceye.com<mailto:francisco.pinto at surgiceye.com>> wrote:

Dear fellow Gate users,



I would be thankful to get some assistance with a current issue I'm facing. I am currently trying (and failing) to simulate the following scenario:

- A voxelized phantom defined via a CT dataset in Analyze format.

- A source placed inside the phantom.

- A simple detector aiming towards the source.



The problem I'm facing occurs when I place the detector inside the bounds of the voxelized phantom: When outside the bounds, the detector registers hits as expected. As soon as I move it inside the bounds, however, no hits are registered.



Is this a known limitation or am I doing something wrong? I'm using the latest develop Gate on Ubuntu 16.04, CPU-only single core simulation.

You may find all the relevant short scripts including the CT dataset here (17MB tgz): https://drive.google.com/open?id=0BzM9gTEQ3DYyYWFOcVRibklGdVk

Use runSim.sh to run the simulation (you may need to change the Gate binary's name in the script).



If anyone has any tips or pointers, they would be very much appreciated.



Cheers and thanks in advance,

Francisco



Francisco Pinto



Principal Software Engineer
SurgicEye GmbH
Tel: +49 89 54 99 89 0 - 21

_______________________________________________
Gate-users mailing list
Gate-users at lists.opengatecollaboration.org<mailto:Gate-users at lists.opengatecollaboration.org>
http://lists.opengatecollaboration.org/mailman/listinfo/gate-users



--
David Sarrut, Phd
Directeur de recherche CNRS
CREATIS, UMR CNRS 5220, Inserm U1206
Centre de lutte contre le cancer Léon Bérard
28 rue Laënnec, 69373 Lyon cedex 08
Tel : 04 78 78 51 51 / 06 74 72 05 42
http://www.creatis.insa-lyon.fr/~dsarrut
_________________________________
 "2 + 2 = 5,  for extremely large values of 2"
_________________________________
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/mailman/private/gate-users/attachments/20160826/b9aa46fe/attachment.html>