An Imaging Camera for Biomedical Application Based on Compton Scattering of Gamma Rays
Fontana, Cristiano Lino
FIS/04 Fisica nucleare e subnucleare | FIS/07 Fisica applicata (a beni culturali, ambientali, biologia e medicina)
In this thesis we present the R&D of a Compton Camera (CC) for small object imaging.
The CC concept requires two detectors to obtain the incoming direction of the gamma ray.
This approach, sometimes named ``Electronic Collimation,'' differs from the usual technique that employs collimators for physically selecting gamma-rays of a given direction.
This solution offers the advantage of much greater sensitivity and hence smaller doses.
We propose a novel design, which uses two similar Position Sensitive Photomultipliers (Hamamatsu 8500) coupled to different scintillators (one plastic and one inorganic).
Assets of just one kind of detector are the simplicity of design and operation.
Along the experimental apparatus we present our original algorithm for image reconstruction, that was tested with a Geant4 Monte Carlo code.
Employed on experimental data, we obtained a resolution of 6 mm, which is suitable for small animal imaging (such as rats or rabbits) and for small human organs imaging (thyroid and prostate).
The prototype was designed to be a compact modular element that can be extended placing more similar detectors side by side