[Gate-users] Voxelized source

Ismet Isnaini ismeth74 at yahoo.com
Thu Feb 17 01:17:54 CET 2011

Hi, Thanks for the reply.. 

yes, I have tried different kind of ratio... 
1Kbq point source with background of 1Bq, but the result is the same.
( I also read in the documentation, that the background shouldNOT be zero, is 
that right?)

What I mean is I could not see the point source, not the background.
All the background seems to have high activity.. the image / sinogram is just an 
uniform square


I am using an ASCII file for the input file, with a linear translator of 1Bq per 
voxel as the scale.

Could you please explain the effect of total activity in the Voxelized input 
file in relation to the activity of individual voxel ???


From: Simon Stute <gate.stute at gmail.com>
To: Ismet Isnaini <ismeth74 at yahoo.com>
Cc: GATE mailist <gate-users at lists.opengatecollaboration.org>
Sent: Thu, February 17, 2011 1:56:46 AM
Subject: Re: [Gate-users] (no subject)

Hi Ismet,

You set a point/background ratio of 10000 ! it is probably the reason why you do 
not see the background in your projection.
Did you try to set a background activity of 1kBq, so that you get a ratio of 10 


On Wed, Feb 16, 2011 at 3:38 PM, Ismet Isnaini <ismeth74 at yahoo.com> wrote:

dear everyone...
>I have been running a simulation using a voxelized source (a simple point 
>off the centre) 100x100 voxel of 1 slice.
>But, instead of using a voxelized phantom, I am using a a cylindrical phantom
>and placed the voxelized source inside this phantom. Is this OK ?
>The result shows as if it does not recognized the low region of the source (The
>hot area was around 10KBq, and the rest is 0 or 1 Bq, and simulation time 
>from 100-500 sec). The sinogram / image produced is a square of 100x100 voxel 
>not uniform  activity..
>Can anybody suggest, what was wrong with it ?
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