【摘要】 在微机上进行图象重建可增加ＣＴ系统的灵活性并降低造价，但必须选择适当的算法并改进计算程序，才能达到一个可以接受的计算速度。提出了的基于“旋转极坐标反投影”概念的几何参数表方法，即提前将投影地址和反投影权重计算好，以表格形式存放，在反投影过程中仅需查表调用，可避免在反投影过程中进行大量费时的计算，从而大大减少了计算工作量。几何参数表方法对二维及三维图象重建都可应用，实验结果说明采用几何参数表后，至少可减少反投影时间一个数量级。实现了在微机上快速重建ＣＴ图象。更多还原

【Abstract】 Reconstructing image on a microcomoputer is able to increase flexibility for the CT system and to reduce cost, however, it can not be acceptable unless the CT systems have tolerable calculating speed. For this reason it is necessary to select appropriate algorithm and to improve calculating program. This paper presents the geometric parameter table method based on the concept of rotating polarcoordinate back projection, i.e., calculating the data of projection addresses and back projection weights in advance, saving them in form of parametertable, in course of back projection the work which only needs to do by computer is to look up the table. This method avoids huge timeconsuming calculation in the course of back projection, thus the amount of calculation is greatly reduced. The geometric parameter table method is applicable to both 2D and 3D image reconstruction. The results show that by using geometric parameter table the time for back projection is reduced by a factor of 10 at least. Fast reconstructing CT image on a microcomputer is realized.更多还原