This thesis describes an innovative method for cancer diagnosis that provides not only information about the localization of tumor in the human body but also about its structure. The most effective method for cancer prevention is early diagnosis. It is expected, that training a model on a larger dataset, without a burden of correlation caused by a limitation in the size of the simulations, may improve the results for NaI:Tl detector.Ĭurrently, cancer is the second cause of death worldwide. Nonetheless, based on simulated data from inexpensive, less sensitive NaI:Tl detector obtained model?s accuracy has been only slightly lower. The best results have been achieved for the LaBr3:Ce detector. Multiple neural network models have been trained and tested using 7-folds cross-validation in order to analyze how does detector?s sensitivity impact model?s precision. The data samples used to train and validate the performance of the used algorithms were based on realistic Monte Carlo simulations which formed histograms of energy depositions for three intervals of detection gamma quanta time. This work presents the feasibility studies of mustard gas recognition using neural network algorithms and data samples measured by a novel, non-invasive device, which is being developed at the Jagiellonian University within the framework of the SABAT (Stoichiometry Analysis By Activation Techniques) project. The measurements of light attenuation length revealed, that for higher voltages the charge output of the detector decreases exponentially with decreasing distance of irradiation point to the photocathode. The study showed that such a detector is linear. Also it was checked the results depends on the distance between crystal and the collimator with source. Taking into account the results of the energy resolution, its dependence on the energy of gamma quanta was plotted and arameterized. This is the best result that can be obtained when using a crystal as a scintillation material. The energetic resolution for the Cesium line (662 keV) was about 3%. The performed measurements concerned such quantities as: energy resolution, time resolution, light attenuation length and light output. The performed research included measuring energy resolution for standard radioactive sources (22Na, 137Cs, 133Ba, 60Co and 152Eu) and for elements activated by fast neutrons (in AmBe source) emitting high energy gamma quanta. Such a detector has the best energy resolution among such materials. The aim of this work was to characterize the scintillation detector with LaBr3:Ce:Sr crystal for SABAT project, involving the use of neutrons in the detection of hazardous materials. This createsĪ possibility for high-quality simultaneous imaging of the whole human body. Ultimately, the sensitivity achieved with the studied Total Body scanners is almost uniform along the whole patient with an additional increase on its sides for both double and triple coincidence imaging. The acquired maximal total sensitivity of 30.63(06+/-31) proves to again surpass the traditional crystal-based system up to ~5 times. Furthermore, due to the possibility of the positronium mean lifetime imaging guaranteed by the J-PET technology, its sensitivity based on the triple coincidence technique has been evaluated.
At the same time sensitivity at the center of the tomograph can reach up to 124.1(1.0+/-1.1). Such results exceed the conventional PET systems (represented by the Biograph Vision) by a factor of ~4.5 and ~15 respectively. The obtained results demonstrate that the standard imaging total sensitivity achievable with the Total Body J-PET scanners equals to 25.92(05+/-04) for theĢ meter long two-layer tomograph and 84.74(0.9+/-1.1) for the 2.5 meter long fourlayer tomograph.
#Kosmiczna synchronizacja software
Its principle of operation, as well as detailed validation by comparison with GATE software is presented in this work. Moreover, a Toy Monte-Carlo model has been developed as a simplified approach to the sensitivity investigation. In order to achieve this goal a simulation-based study was carried out with a use of the standard Monte-Carlo simulation software - Geant4 Application for Tomography Emission (GATE). The main aim of presented thesis is to investigate sensitivity of the Total Body J-PET scanners as a function of their axial field of view and inner module construction, as well as assessing the influence of the angular acceptance criterion (used for PET performance optimization) on this characteristic.
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