简述了锥束CT(CBCT)的工作原理,分析了X射线源连续照射和脉冲式照射两种成像方式的优劣,采用脉冲式照射成像方式,完成了低辐射CBCT系统成像的设计。在此基础上,实现了PaxScan 2520平板探测器的内、外两种读图触发模式下的X射线成像。实验结果表明,相比于X射线源连续照射的成像方式,脉冲式照射成像较大地减少了X射线辐射时间,提高了CBCT的安全性能。内、外两种触发模式下的脉冲式X射线成像对于图像的质量没有区别,模式的选择取决于是否需要主动控制X射线的发射。

The basic working principle of Cone Beam Computer Tomography (CBCT) is briefly described, the advantages and disadvantages of both continuous and pulsed X-ray imaging methods are analyzed, and the pulsed X-ray imaging method is adopted to implement the design of low-dose CBCT. On the basis of this, the internal and external trigger modes of PaxScan 2520 flat panel detector are realized. The experiment results show that the method of continuous X-ray imaging needs dozens of seconds for the process rotating a circle, in the meanwhile, the method of pulsed X-ray imaging only needs about four seconds for doing same job. In a word, pulsed X-ray imaging reduces the X-ray radiation time considerably and improves the safety performance of CBCT significantly. Besides, pulsed X-ray imaging with internal and external trigger modes has no difference in terms of image quality. The choice for the modes depends on whether or not needs active control for X-ray emission.