摘要
本文利用闪烁体的吸收发光特点，并结合计算机断层扫描技术，提出了对核辐射剂量场分布进行实时成像测量的新方法──阵列式吸收发光CT法，研制出闪烁光纤阵列构成的核探测器及其伺服控系统．采用高灵敏度的电荷耦合器件（CCD）拾取探测器产生的微弱闪烁光信号，并用定点采集的方法对视频信号进行数据的快速采集．在图像重建方法上，提出了迭代滤波反投影重建方法和利用非完全投影进行数据修复，对获取的投影数据进行变换和处理．通过选择滤波函数及其适当的参数，获得最佳滤波效果，以重建剂量场的二维场分布，从而建立了核辐照剂量场的实时、高精度的成像测量系统．实验及模拟实验结果均很好地证实了，该测量方法的可行性和测量系统工作的可靠性．
By the comprehensive analysis of existing mcasuring methods, a new method is proposed in the paper tomeasure the nuclear radiation dose field with array absorption-emission computed tomography. The detector based on scintillation optical fiber array and its servo-control system are designed. The weak optical signal is measured by Charge Coupled Devices (CCD) and the formed visual signal is quickly sampled with the method of testing fixed signed points. The reconstruction method of iterative filter back projection and the data renovation based on noncomplete proection are proposed to reconstruct dase field much more accurately. The filter function is also an important factor in the image reconstruction. The Butterworth filter function is chasen. By adjusting its parameters, we have obtained optimum result. Finally, all the experimentationshow that the methods proposed in paper are proper and whole measuring system is advanced and feasible.
出处
《电子学报》
EI
CAS
CSCD
北大核心
1999年第12期115-118,共4页
Acta Electronica Sinica
基金
国家自然科学基金
关键词
核辐射
剂量场
断层扫描
实时成像
测量
nuclear radiation dose field
scintillation
computed tomography
iterative filter back projection
image reconstruction
