Non-invasive examinations, which do not require a surgical operation, play an important role in diagnostic medicine. Such an imaging procedure of nuclear medicine is positron emission tomography (PET). This method enables to gather information on the functional condition of the body in the form of 2-, and 3 dimensional images. PET can be efficiently used targeting a range of different diseases, promoting the early detection of abnormalities in several fields such as oncology, neurology and cardiology.
The basic principle of the procedure is that a chemical compound containing a radioactive isotope is injected into the patient’s body. By detecting gamma photons, which are formed in the radioactive decays, enables to map the spatial distribution of the substance, which characterizes the physiologic activities of the body. A significant part in this process is the detector module, which detects these gamma photons. The image reconstruction process requires the determination of the position where gamma photons are absorbed in the detector. This is called the point of interest (POI), and it is estimated using the output signals of the detector.
The aim of this MSc thesis is to study possible methods for POI estimation in the case of certain detector constructions and system parameters, to recommend an efficient solution, and establish the FPGA implementation of the proposed method.