Doctor of Philosophy
Centre for Medical Radiation Physics, School of Engineering Physics - Faculty of Engineering
Perera, Lakshal, Investigations of a novel small animal PET scanner with depth of interaction using GATE and a newly developed data rebinning application, PhD thesis, Centre for Medical Radiation Physics, School of Engineering Physics, University of Wollongong, 2009. http://ro.uow.edu.au/theses/678
Current Positron Emission Tomography (PET) detectors suffer degradation in the spatial resolution at the edges of the field of view. This occurs as a result of the lack of depth of interaction (DOI) information which causes uncertainty in deducing the Lines of Response (LOR) between coincident events. The Centre for Medical Radiation Physics at the University of Wollongong has developed a novel detector module for use in small animal PET which will provide depth of interaction information while retaining the sensitivity of current scanners. This will result in superior imaging together with the ability to locate smaller lesions. This work focuses on preliminary investigations of the suitability of replacing the bulky scintillator crystals and photomultiplier tubes of traditional PET detector modules with compact LYSO scintillator crystals individually coupled to Si photodetectors. Preliminary simulations focused on optimising the detector module were per- formed using the GATE Monte Carlo package. Data from the simulations was processed using a newly developed sinogram binning application. This application is exible and able to adapt to numerous detector geometries based on user input. Depth of interaction information is automatically considered when binning the sino-gram. Comparison of data from Monte Carlo studies processed with the sinogram binning application and experiments using a microPET Small Animal PET scanner are presented to illustrate the suitability of the sinogram binning application for future Monte Carlo PET data processing. The spatial resolution results which are provided indicate this detector module is capable of providing superior performance to monolithic scintillator crystal detector modules. Furthermore, notable advances can be made towards a significant reduc-tion of the radial elongation artefact at the edges of field of view. Other parameters which are important to the process of quantifying the performance of a small ani-mal PET scanner are also presented including optimisation of energy windows, the crystal size and detector configuration.
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