Research On Single PMT Fluorescence Molecular Tomography Based On Frequency Modulation And Spatial Code Detection

With so many advantages such as non-invasive,high specificity,non ionizing radiation,fluorescence molecular tomography(FMT)has great potential application in the fields of early cancer diagnosis,drug efficacy follow-up evaluation,surgical navigation and other medical fields.In the existing FMT imaging system,a charge coupled device(Charge Coupled Device,CCD)or an electron multiplying charge coupled device(Electron Multiplying Charge Coupled Device,EMCCD)is used to obtain measurement data,but for the early detection of smaller tumor tissue,Due to the limited sensitivity of CCD or EMCCD,it may cause signal loss during the collection of fluorescent signals.The use of photomultiplier tubes(PMT)provides a choice for solving this problem.In addition,the current excitation system uses alternating excitation light paths to excite,and the data collection method of time-diagnostic light path collection is time-consuming.How to realize the data collection of multi-point excitation and multi-point measurement while ensuring the advantages of single-point excitation is based on New challenges faced by PMT's high-sensitivity fluorescent molecular tomography system.In order to improve the detection sensitivity of the existing FMT imaging system and optimize the data acquisition mode,this paper proposes a single PMT fluorescent molecular imaging method based on frequency modulation and spatial coding detection.The specific research work is as follows:(1)The construction and verification of the mathematical model based on the frequency modulation method and spatial coding method.The paper explores the mathematical models of frequency modulation method and space coding method.Firstly,the mathematical models of frequency modulation method and space coding method are deduced to make them rigorous in mathematical theory.Secondly,in order to verify the accuracy of frequency modulation method and space coding method,the simulation experiments of image reconstruction of the two mathematical models are carried out.Finally,the quality of reconstructed image and original image are analyzed by using image quality evaluation factors.The experimental results show that the mathematical models of frequency modulation and spatial coding methods have good performance,and can be used in fluorescence molecular tomography with PMT.(2)Single PMT fluorescence molecular imaging based on frequency modulation and spatial coding detection.On the basis of the mathematical models of frequency modulation and spatial coding,the paper proposes a single PMT fluorescence molecular tomography technology based on frequency modulation and spatial coding detection.Firstly,the overall mathematical model combining frequency modulation and spatial coding method is derived by using mathematical theory.Secondly,to verify the validity and accuracy of the model,the simulation experiments of simple regular geometry model and non-uniform cylinder model are designed.Finally,the quality of reconstructed image and original image is analyzed by using image quality evaluation factors.The experimental results show that the proposed method is effective and accurate.