[Gate-users] Total Activity / voxels / and source activity impact on Voxel Source

[Khalid Hussain]

Dear Xinjie,

Thanks a lot for your reply.

The tissue constitution is as given below;

[image: image.png]
As the activity per voxel will be 191Bq (1218 MBq/6388800 ~= 191 Bq/voxel),
So, I think the correct activity.dat file will be as given below ( I want
to assign 10 times more activity to voxel with value 7)?
[image: image.png]

Thank you so much for your guidance.



On Sun, Oct 10, 2021 at 11:14 PM Xinjie Cao <xinjie.cao at stonybrook.edu>
wrote:

> Hello Khalid,
>
> I am not sure why you set activity twice in both the .dat file and the
> macro. But from my experience, if you are using voxelized phantom for
> simulation and try to attach some specific activity value to voxels, you
> just need to set the activity in the .dat file ( need to notice that the
> default unit in the .dat file is Bq).
>
> So, let me assume that you are attaching all your activity to voxels with
> label 7 as you showed in the image and all your phantom voxels are labeled
> as 7  (because you didn't mention the constitution). The total activity
> level of 32.928 mCi, which is ~ 1218 MBq will be attached to all voxels of
> your phantom matrix evenly. 1218 MBq/6388800 ~= 191 Bq/voxel. But for most
> scenarios, you do not want to just assign all voxels with single activity
> level. You need to reference some papers about some specific scenarios you
> would like to study and attach different activity levels to different
> tissues.
>
> Hope this helps!
>
> Best,
> Xinjie
>
> On Sun, Oct 10, 2021 at 4:30 AM Khalid Hussain <
> khalidhussain1134 at gmail.com> wrote:
>
>> Dear Gate Users,
>>
>> I am using a voxel source and have defined the activity of each voxel in
>> the activity.dat file.
>> Here I have a question about the total number of particles. If I look at
>> the stat file, activity file, and source files, and cannot be sure how the
>> activity is working on and being calculated.
>> My voxel image has dimensions of 220x220x132 with 0.5mm^3 voxel size and
>> the total number of voxels is 6388800 and the volume is 411.601cm^3 and I
>> want to assign 80nCi/cm^3 activity to my voxel source. Mathematically the
>> total activity which should I give to the voxelized source is 32.928133 mCi
>> but I need your guidance on how can I assign this activity to my voxelized
>> source.
>>
>> I checked by changing the source activity probably not influencing the
>> total number of particles.
>>
>> Please advise
>>
>> [image: image.png]
>> [image: image.png]
>>
>> [image: image.png]
>>
>>
>> Regards
>>
>> *KHALID HUSSAIN *| *PhD Scholar*
>> *Universiti Putra Malaysia (UPM), Malaysia*
>> Email:hussain.khalid at student.upm.edu.my
>> Cell: *+60-11-6455-2354*
>> _______________________________________________
>> Gate-users mailing list
>> Gate-users at lists.opengatecollaboration.org
>> http://lists.opengatecollaboration.org/mailman/listinfo/gate-users
>
>
>
> --
> *....................................................*
> *Xinjie Cao*
> *M.Eng. / Ph.D. Candidate*
> *Research Project Assistant*
> *Department of Electrical and Computer Engineering & Radiology *
> *Novel Medical Imaging Technologies Lab*
> *Health Science Center Level 8*
> *Stony Brook, NY 11794-8460 *
> *Tel: +1 (631)202-9445*
> you.stonybrook.edu/goldan/people/
> *email: **xinjie.cao at stonybroo*k.edu <xinjie.cao at stonybrook.edu>
>
>
> *....................................................*
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 95887 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0005.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 124706 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0006.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 33299 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0007.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 16058 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0008.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 9310 bytes
Desc: not available
URL: <http://lists.opengatecollaboration.org/pipermail/gate-users/attachments/20211010/1979d05b/attachment-0009.png>