[gate-users] Doubts about voxelised phantoms

[Susana Silva]

Hi everybody!

I have some questions about voxelised phantoms. I'm trying to use a voxelised phantom in GATE. Some of you may know it - the MOBY phantom. So, to use it in GATE I have to update the materials database, and create a macro file where the materials are defined to the respective voxels. To understand this I use the Hoffman phantom. My question is: to made the macro file with the materials and the correspondent voxels how can i reference each voxel? In another words, how can i reference that voxel (x=145, y=34, z=45) is made of material "abc"? The only example that i have (in the user guide, the brain) is the one referencing voxels 1 to 25 made of material a, voxels 26 to 50 is of material b, and so on. But this only references one dimension, and i have a three dimension phantom.
I'm having a hard time to figue out how can i say to GATE that my voxels (well, ALL voxels do) have 3 dimensions and the position of each voxel can only be referenced with the reference to the position in the 3D space or, at least, 2D space if i work with slices of the phantom.

I hope you understand my doubts in here, and can help me.
Thanks in advance.

Cheers,

Susana Silva