EduGATE - simple examples for educative purpose using the GATE simulation platform

AIM
The GATE (1) platform is based on the GEANT4 package developed at CERN/Geneva. It has received a wide acceptance in the field of simulating medical imaging devices including SPECT, PET, CT and also applications in radiation therapy. This is mainly due to the fact, that GATE can be configured by commands, which are, for the sake of simplicity, listed in a collection of one or more macro files. The aim of this contribution is to use all helpful features of GATE to provide insights into the physics of medical imaging by means of a collection of very basic and simple GATE macros in connection with analysis programs based of ROOT.
METHODS
Simplifying or extending examples for GATE (current version: 6), which come with the basic distribution, we configured the relevant macro files for running GATE in such a way, they are easily modified with a text editor, hence, allowing the user or student to study the effect of changing the material of a phantom, switching the type of radioactive source or to select or de-select a specific type of electro-magnetic interaction. The results from the simulation are usually stored in binary files readable by the ROOT package, as projection files useful for reconstruction programs or even in ASCII format, for fast inspection. Especially the ROOT package turned out to be a very useful utility to analyze the output data from the simulation under various aspects. ROOT programs, written in c++, serve as tools to either simply visualize basic distributions or select or resort the data into formats readable by programs for image reconstruction. The detector setups are kept very simple but expose the basic principles of imaging. The EduGATE examples were tested and successfully presented during medical physics lectures to point the students to the various aspects of medical imaging related to the basic physical principles. Currently, four imaging systems have been created: simple coincidence channel, PET, Gamma camera (planar) and SPECT. The users can select from a list of various isotopes, different detector material, experience the influence of attenuating material in the form of an extra cylinder around the source, whose shape and activity can also be varied. Analysis modules to be applied within the ROOT environment are also
provided. They serve as a means for students to start exploring the data structures and learn, how to analyze and evaluate a specific detector configuration that has be simulated under various conditions.
CONCLUSIONS
It opens an interesting opportunity for lecturers as well as students to use powerful tools, while becoming acquainted with the world of medical imaging. EduGATE uses solely Open Source software, which is freely available and can be used on any platform, where GATE and ROOT are operating.
(1) S. Jan et al 2004 GATE: a simulation toolkit for PET and SPECT. Phys. Med. Biol. 49, 4543–4561