Schorr B, Townsend D
Phys Med Biol. 1981 Mar;26(2):305-12. doi: 10.1088/0031-9155/26/2/009.
One approach to the three-dimensional, tomographic reconstruction of data from a planar dual-detector stationary positron camera necessitates frequency-space filtering of the image obtained from back-projection. It is therefore useful to have a closed-form expression for the appropriate filter, but the derivation is complicated by the fact that the camera measures only a limited angular range of projections. Nevertheless, suitable expressions can be obtained and are here derived for detectors of rectangular and circular cross-section.
从平面双探测器固定式正电子相机进行数据的三维断层重建的一种方法需要对通过反投影获得的图像进行频率空间滤波。因此，对于合适的滤波器有一个封闭形式的表达式是很有用的，但是由于相机仅测量有限角度范围的投影这一事实，推导过程变得复杂。然而，可以得到合适的表达式，并且在此为矩形和圆形横截面的探测器推导出来。
