Phantoms#

Phantom: IEC 6 spheres NEMA phantom#

An analytical model of the 6 spheres IEC NEMA phantom is provided. It can be used as follows:

import opengate as gate
import opengate.contrib.phantoms.nemaiec as gate_iec

sim = gate.Simulation()
iec_phantom = gate_iec.add_iec_phantom(sim, 'iec_phantom')
activities = [3 * BqmL, 4 * BqmL, 5 * BqmL, 6 * BqmL, 9 * BqmL, 12 * BqmL]
iec_source = gate_iec.add_spheres_sources(sim, 'iec_phantom', 'iec_source', 'all', activities)
iec_bg_source = gate_iec.add_background_source(sim, 'iec_phantom', 'iec_bg_source', 0.1 * BqmL)

The rotation should be adapted according to your need. The layout of the 6 spheres can be changed with the parameters sphere_starting_angle (angle of the first sphere, default 180 deg, the 37 mm sphere) and toggle_sphere_order (reverse order, the first sphere is then the 10 mm one) of the add_iec_phantom command, to match a given physical phantom.

Materials: the body and the shells of the spheres are IEC_PLASTIC (PMMA, 1.18 g/cm3), the interior and the spheres are G4_WATER, and the central (lung) insert is IEC_LUNG: polystyrene beads and water, 0.30 g/cm3 (gate_iec.iec_lung). Up to opengate 10.1.1 (before issue #1211), the insert was G4_LUNG_ICRP (lung tissue, 1.04 g/cm3); to reproduce older simulations, set the material of the volume <name>_center_cylinder_hole to G4_LUNG_ICRP.

../_images/iec_6spheres.png

Two versions of the phantom are available, selected with the parameter version of add_iec_phantom, and named after their total (outer) length:

version

total length

top and bottom walls

interior length

sphere centres (z)

iec_214

214 mm

10 mm

194 mm

+27 mm

iec_220

220 mm

3 mm

214 mm

+37 mm

iec_214 is the default (GATE 10). iec_220 corresponds to the GATE 9 macro (GateContrib NEMA_IEC_2001.mac) and can be used to reproduce GATE 9 simulations. In both versions, the sphere centres are 70 mm below the inside of the lid, as specified by NEMA, and the z positions above are relative to the centre of the phantom.

iec_phantom = gate_iec.add_iec_phantom(sim, 'iec_phantom', version='iec_220')

The functions that return the default sphere centres also take this parameter, e.g. gate_iec.get_default_sphere_centers_and_volumes(version='iec_220').

Examples can be found in test015 (and others).

Phantom: cylinder phantom for PET NECR#

An analytical model of the simple NECR phantom (cylinder and linear source) is provided. It can be used as follows:

import opengate as gate
import opengate.contrib.phantoms.necr as gate_necr

sim = gate.Simulation()
necr_phantom = gate_necr.add_necr_phantom(sim, 'necr_phantom')
necr_source = gate_necr.add_necr_source(sim, 'necr_phantom')
necr_source.activity = 1000 * Bq

Example can be found in test049 (and others).

Phantom: Gammex 467#

An analytical model of the Gammex 467 phantom is provided. It can be used as follows:

import opengate as gate
import opengate.contrib.phantoms.gammex467 as gammex467_phantom

sim = gate.Simulation()
gammex467_phantom = gammex467.add_gammex467_phantom(sim)
../_images/gammex467.png