[Gate-users] Dose Actor on Volume of Water

[Maikol Salas Ramirez]

Hi Christopher

Yes, I think you are right when you write "I believe the problem lies in my
discretization of the dose actor". Did you play with the values of
setVoxelSize?
What you have to see is the target sphere (R=1cm), 1mmx1mmx1mm is enough to
see a sphere form with a sphere size like this. Just remenber that setSize
is not necessary. Did you remove the *#* for Position, voxelSize and
Resolution lines? otherwise they do not work.

Best regards
Maikol


El jue., 22 nov. 2018 a las 11:28, Christopher Watanabe (<
chris.r.watanabe at gmail.com>) escribió:

> Hi Maikol,
>
> Thanks for the response. I'm a little confused by this though. Generally,
> no matter where I put the source, shouldn't I expect a spherical
> distribution around it? (At least the way I defined it, essentially being
> an isometric point source)
>
> I believe the problem lies in my discretization of the dose actor. When
> one attaches the dose actor to the volume, does it automatically take the
> shape of the volume? I guess in the end, I'm just not sure how to define my
> dose actor appropriately, because the dose really shouldn't be cubically
> shaped, especially given that the target around the source is a spherical
> volume of water...
>
> Best,
>
> Chris
>
> On Tue, Nov 20, 2018 at 2:44 PM Maikol Salas Ramirez <mmsalas at gmail.com>
> wrote:
>
>> Hi Christopher
>>
>> 1- If you define a sphere in the 0,0,0 position the sphere has 1/4 of his
>> volume in the each of the 4 voxel that are around 0,0,0 maybe this is with
>> you see a cube. If you move the sphere to 0.5,0.5,0.5 mm, it will be in the
>> center of the voxel 1,0,0, then you will see this voxel brighter than
>> others around. This is tricky, am it is a normal error when the people used
>> NM and CT in the simulation (NM needs a shift).
>>
>> 2- In the dose actor you need at least lo specify the Position, voxelSize
>> and Resolution (setSize is not necessary). I guess, you are only testing,
>> because put a sphere with a similar size to the voxel es a bit strange.
>> Normally for a voxel kernel the people use a box with the same size to tha
>> voxel.
>>
>> Best regards
>> Maikol
>>
>>
>>
>> El mar., 20 nov. 2018 a las 14:11, Christopher Watanabe (<
>> chris.r.watanabe at gmail.com>) escribió:
>>
>>> Hello fellow Gate Users,
>>>
>>> I'm running simulations of a radioactive source placed within a volume
>>> of water. Below I show snippets of showing the volume of water made inside
>>> a world of air (3cm x 3cm x 3cm) and the dose actor.
>>> [image: image.png]
>>> [image: image.png]
>>> I've played with the dose actor characteristics quite a bit, and I've
>>> found that no matter what I do, the .mhd dose file output consistently
>>> shows a Cube shaped dose distribution. This doesn't make sense to me, as
>>> I've defined a spherical source of radiation and attached the dose actor to
>>> the sphere of water...Can anyone suggest something that might be going
>>> wrong? My source I define below:
>>> [image: image.png]
>>> Thanks a lot in advnance! I think if there's no problem with my dose
>>> actor definition, then I must be doing something wrong with my source
>>> definition.
>>>
>>> Best Regards,
>>>
>>> Chris
>>>
>>> _______________________________________________
>>> Gate-users mailing list
>>> Gate-users at lists.opengatecollaboration.org
>>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>>
>>
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