Voxelized source#
Description#
A voxelized source can be created as follows:
source = sim.add_source('VoxelSource', 'vox')
source.particle = 'e-'
source.activity = 4000 * Bq
source.image = 'an_activity_image.mhd'
source.direction.type = 'iso'
source.energy.mono = 100 * keV
source.attached_to = 'my_volume_name'
This code create a voxelized source. The 3D activity distribution is read from the given image. This image is internally normalized such that the sum of all pixels values is 1, leading to a 3D probability distribution. Particles will be randomly located somewhere in the image according to this probability distribution. Note that once an activity voxel is chosen from this distribution, the location of the particle inside the voxel is performed uniformly. In the given example, 4 kBq of electrons of 140 keV will be generated.
Like all objects, by default, the source is located according to the
coordinate system of its attached_to volume. For example, if the attached_to
volume is a box, it will be the center of the box. If it is a voxelized
volume (typically a CT image), it will the center of this image: the
image own coordinate system (ITK’s origin) is not considered here. If
you want to align a voxelized activity with a CT image that have the
same coordinate system you should compute the correct translation. This
is done by the function
gate.image.get_translation_between_images_center(). See the contrib
example dose_rate.py.
