【摘要】 采用探测器几何效率推导了高灵敏度SPECT系统的点源扩展函数,指出了考虑探测器晶体厚度修正的必要性,在小型γ相机上用99mTc的实验结果证明了这一过程,并指出取消准直器在大幅提高灵敏度的同时能够成像的基本根据。在此基础上,讨论了高灵敏度SPECT的灵敏度和空间分辨率,指出了进行小动物成像的可行性;Rose标准的讨论指出灵敏度的大幅提高,明显削弱了背景噪音带来的图像分辨影响,使得动态过程的成像能拥有很好的时间分辨率。更多还原

【Abstract】 Geometric efficiency was used to derive the point spread function(PSF) of a SPECT system which uses no collimator.The thickness of the NaI crystal was also considered and a modification of the PSF was made.An experiment with the γ camera was used to support the derivation.It showed that the system had a high sensitivity and provided an acceptable image at the same time.Based on above results,the sensitivity and resolution of the no- collimator system was discussed to show the potential of the system in small animal imaging.Then Rose criterion was introduced to show that with a high sensitivity the influence of the noise was weakened and a better time resolution in dynamic imaging was provided.更多还原