三棒源衰减重建中的随机校正算法  

Randoms Correction Algorithm for Attenuation with Three-Rod Source During Reconstruction

作　　者：滕月阳[1] 张铁[1] 

机构地区：[1]东北大学理学院,辽宁沈阳110004

出　　处：《东北大学学报（自然科学版）》2010年第12期1705-1708,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(10771031)

摘　　要：在正电子发射断层成像系统中,单棒源衰减扫描消耗大量时间,使用3个棒源可减少扫描时间,但是带来大量随机符合事件.针对三棒源衰减扫描的特点,设计了一种约束单光子随机校正算法,每个棒源位置对应一个随机弦图,利用3个扇束接收窗进行过滤,过滤后的所有随机符合事件组成可应用的随机弦图.使用NEMA标准中的图像质量和衰减校正精度参数作为评价准则,实验结果显示本文方法在衰减扫描时间减少50%的前提下获得与单棒源一致的图像质量与衰减校正精度.In PET（positron emission tomography）system,the single-rod source spends a lot of time on the photon-attenuated scan.Although the three-rod source can reduce the scanning time,it brings a lot of random coincidences.A restricted single-photon algorithm is therefore designed for randoms correction due to the three-rod photon-attenuated scan,i.e.to provide a random sinogram for each and every rod position so as to filter all by three fan-beam acceptance windows.Then,a practical random sinogram is provided comprising all filtered random coincidences.The algorithm was evaluated by the image quality and correction accuracy of attenuation as specified in NEMA standard.Experimental results showed that the proposed algorithm can obtain the same image quality and correction accuracy of attenuation just like what can be obtained from single-rod source with half of the photon-attenuated scanning time saved.

关 键 词：衰减校正 随机校正 单光子法 扇束接收窗 校正精度 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]