CAJ | 학술논문

正电子发射型计算机断层成像(PET)作为一种重要的临床影像技术, 其图像重建技术非常重要. 本文将 γ 光子飞行时间信息(TOF)加入到系统响应矩阵并提出基于 TOF 的图像重建算法. 基于压缩感知原理, 利用全变差和小波变换对图像进行稀疏化, 以它们为正则项构建目标函数; 并运用惩罚函数的方法将目标函数求解分解为二次优化和稀疏约束2个子问题, 运用交替求解的方法逐一求解, 降低了求解的复杂性. 采用蒙特卡罗对Derenzo模型进行仿真重建并比较不同算法的成像效果, 结果表明, 加入 TOF 信息和利用稀疏约束能够更好地拟制噪声, 图像重建效果优于传统算法. 文中进一步研究了系统时间分辨率和时间采样间隔对图像重建的影响, 结果表明, 时间分辨率越高、时间采集间隔越短, 重建效果越好.
정전자발사형계산궤단층성상(PET)작위일충중요적림상영상기술, 기도상중건기술비상중요. 본문장 γ 광자비행시간신식(TOF)가입도계통향응구진병제출기우 TOF 적도상중건산법. 기우압축감지원리, 이용전변차화소파변환대도상진행희소화, 이타문위정칙항구건목표함수; 병운용징벌함수적방법장목표함수구해분해위이차우화화희소약속2개자문제, 운용교체구해적방법축일구해, 강저료구해적복잡성. 채용몽특잡라대Derenzo모형진행방진중건병비교불동산법적성상효과, 결과표명, 가입 TOF 신식화이용희소약속능구경호지의제조성, 도상중건효과우우전통산법. 문중진일보연구료계통시간분변솔화시간채양간격대도상중건적영향, 결과표명, 시간분변솔월고、시간채집간격월단, 중건효과월호.
Positron emission tomography (PET) is an important clinical imaging technology, the image recon-struction of it is important. In this paper the time of flight (TOF) information ofγ photon was added to the system response matrix. According to the compressed sensing theory, the signal was sparsified with the total variation and wavelets transform, and they were used as regularization to construct the objective function. Using the pen-alty function method, the objective function was decomposed into two sub-problems of solving quadratic optimization and sparse regularization with the idea of penalty function, and the alternative iteration methods were used to reduce the solution complexity. The Monte Carlo simulations with Derenzo phantom were applied to compare the efficiency of different algorithms, and the results show that the proposed methods perform better than the traditional algorithms. The thesis further investigated the effect of the system temporal resolution and time acquisition interval on the quality of the image reconstruction, the results show that the higher time resolution and shorter acquisition time interval can get better reconstruction results.