论文部分内容阅读
为使人体对γ射线的衰减造成核医学影像的失真和定量误差得到校正 ,在用于发射成像的单光子发射断层扫描机 (SPECT)上安装偏置的线源和平行缝准直器 ,可以获得倾斜的扇形束透射投影。这项构想在三探头 SPECT系统上进行了实验 ,取得了清晰的透射投影。使用 3种方法重建出衰减系数分布图 ,证明倾斜扇形束投影作 36 0°扫描能解决数据截断的问题 ,为这种特殊的投影几何结构推导的公式能够准确地重建出断层图像
In order to correct the distortions and quantitative errors of nuclear medical images caused by the attenuation of gamma rays by the human body, a bias line source and a parallel slit collimator are installed on a single-photon emission tomography (SPECT) scanner for transmitting and imaging, Tilted fan beam transmission projection was obtained. The idea was tested on a three-probe SPECT system with a clear transmission projection. Three kinds of methods were used to reconstruct the attenuation coefficient distribution chart. It was proved that the tilted sector beam projection can solve the data truncation problem. The formula deduced for this special projection geometry can accurately reconstruct the tomographic image