Development And Optimization Of Breast PET System

Cancer is a stubborn disease endangering human health.Breast cancer ranks first among female cancers,and it is also one of the main causes of female cancer deaths.Early screening and early diagnosis are the key to reducing breast cancer mortality and improving the quality of life of patients.Compared with existing breast cancer detection methods,PET imaging technology can detect tumors non-invasively using the metabolism of radiopharmaceuticals by organisms,and can detect early microscopic lesions.Therefore,breast PET can be used as an effective means for early detection of female breast cancer.Based on the advantages of PET imaging technology in breast cancer detection,this thesis is committed to the development of a breast-specific PET imaging system,and optimize it,and finally evaluate the performance of the system.The work of this thesis is mainly composed of the following three parts:1.Completed the design and realization of the breast PET system.In terms of the internal structure design of the system,considering the integration of PET-optical systems,multiple PET basic detection modules(BDM)are used to compare circular,double-plate and quad-plate rectangular structures,and are suitable for optical flat-plate systems The combined dual-plate and four-plate rectangular PET system structure was simulated and verified.In view of the advantages of the four-plate rectangular PET compared to the dual-plate PET in terms of spatial resolution and sensitivity,the four-plate rectangular structure was finally selected.In terms of system appearance design,comprehensively consider the comfort of patient detection,overall system structural stability,aesthetics and other factors,design a beautiful and suitable system shell for breast tissue detection,complete the design and realization of the appearance of the breast PET system.2.Realize the optimization of breast PET system.Aiming at the problems of large amount of collected data,difficult transmission,and long processing time,the data collection and preprocessing optimization plan was designed and realized.In terms of data acquisition,high-performance equipment is used for multi-threaded parallel acquisition,transmission and storage.The theoretical data transmission speed can reach up to 125MB/s,reducing data packet loss;in terms of data preprocessing,multithreaded preprocessing is designed The program greatly improves the data preprocessing speed,which can increase the data preprocessing speed by 10.5 times.Aiming at the geometric error of the system installation,an optimized scheme is designed from the aspects of hardware and software.In terms of hardware,design a fixation scheme that is convenient for installation and can reduce installation errors to ensure the accuracy of system installation;in terms of software,the system geometric errors of the four-plate rectangular PET are analyzed and mathematically modeled,and the two pairs of plates are studied and realized.The correction scheme of the geometric offset error between the two ensures the quality of the reconstructed image.3.The self-developed breast PET imaging system was carried out multiple sets of simulation experiments,and the performance evaluation of the PET system was realized.The results show that the center spatial resolution of the breast PET system is better than 1.5mm,under the 10ns time window and 200-800keV energy window,the center sensitivity of the system is 2.58%,when a pair of detectors are separated by 140mm,the detector time is measured The resolution is 2.10ns,when the system has an activity of 776μCi(28.9 MBq),the noise equivalent count rate curve reaches the peak,and a count of 219 kcps is obtained,when the activity is greater than 1.6MBq(43μCi),the system quantitative error is less than 3.5%.The experimental results show that the developed breast PET system has good performance.