[Gate-users] Use of Moby phantom in GATE

[Susana Silva]

Dear Ramesh,

GATE can't read float data (32 bit)! So you'll need to convert your 
phantom file to unsigned integer (16 bit) format (with IDL or MATLAB for 
instance).The MOBY program produces bin files in float data... as you 
already have noticed.

Here some notes about MOBY implementation inside the GATE platform:

The ActivityRange.dat file is where you define the activity distribution 
inside the phantom (for each voxel or voxels range) = match activity 
values to the voxels number/range,...., is the definition of the 
voxelized source in your simulation!

You have the information about the voxels numbers (assigned an each 
organ or tissue) in the parameters file on the MOBY program. The same 
information is reproduced in the log file at the moment of the 
generation of the phantom files by the program.

You can also check this values if you visualize your phantom file, using 
an image software...

The definition of the range.dat file is where you define each 
tissue/organ of your MOBY phantom (for each voxel or voxels range) = 
match attenuation materials to the voxels number/range, ..., is the 
definition of the voxelized phantom in your simulation!

You can specify the materials of MOBY using the materials database 
(GateMaterials.db) and update the same with new materials (this file 
contains all material parameters required by Geant4 to calculate the 
interaction cross-sections and is easy to modify). In the 4 last GATE 
releases (if I'm correct) the MOBY organs/tissues are all defined on the 
materials database: you don't need to worry about this. You can find 
more materials attenuation information (especially if you want to define 
attenuation in some structures in the MOBY brain) in this link:

http://physics.nist.gov/PhysRefData/XrayMassCoef/tab2.html

If you don't want to simulate the attenuation information you don't need 
to define the phantom! You just need to define the source (shape; type 
of source; distribution of the emission; placement of the sources).

About the organ volumes: if you define only brain activity (inside GATE, 
in your ActivityRange.dat file), and all the other organs with 0Bq 
activity, you can saw in your screen (after launch the simulation) the 
amount of brain voxels for your MOBY phantom!! After that you can 
multiple the total number of brain voxels to your voxel unit size.

Hope this help you.

Best regards,

Susana Branco Silva

On 6/16/11 4:03 PM, RAMESHwar wrote:
> Hello all
> I am trying to use Moby Phantom as voxelized phantom and source.I have two
> files as output from MoBy program, namely moby_act.hv  (header) and
> moby_act.v (binary). These files are in float format.
> However, GATE  needs as uint short as input.
> My problem is that:
> 1.How can I convert moby program output to short, compatible to GATE ??
> 2. In range.dat file, we define some number of materials. Does these number
> should be equal to the materials defined in main file e.g. moby_i33 ??
> Thanks for any suggestions, help
> Ramesh
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