Abstract:Objective:Positron emission tomography is currently used in clinical diagnosis of advanced medical tomography, especially for the diagnosis of heart disease, tumor and brain disorders. Method:In this thesis, I have made some introduction about concept, works and clinical application of PET. A key component of the PET system is the detector, and the thesis also do some data processing of γ photons which received by detector. Then it can make a scatter to observe the distribution of γ photons. Result:The scatter plot shows that the γ photon is not evenly distributed. Conclusion: The PET imaging has a certain degree of error, so it is necessary to correct the data. In addition, with the development of PET, the new detector technology requires constant research and improvement.