Numerical Analysis of Hardening Correction Model of Energy Spectrum for X-ray TICT
-
摘要: 工业计算机断层扫描成像中，由于X射线能谱具有多色性,X射线在透射物质时，能量较低的射线优先被吸收，也即较高能量的X射线的衰减系数比较低能量的X射线的衰减系数小，射线随透射厚度增大，变得更易穿透，即发生了能谱硬化现象。对能谱硬化现象进行了分析，利用Beer定律和X射线与物质作用的特点，提出了能谱硬化修正模型和数值分析，结合Simpson公式，导出了X射线TICT中修正模型的数值解法及其修正方法。对修正后的衰减系数再作卷积反投影重构，即可有效消除能谱硬化造成的影响。
-
关键词:
- X射线 /
- 工业计算机断层扫描成像技术 /
- 硬化修正 /
- Simpson公式
Abstract: In X-ray TICT, the variation of attenuation coefficient with energy leads to low energy radiation being absorbed preferentially. In orther words ,it is the more high energy, the more low attenuation coefficient. With the transmission thickness augmenting, it is easier to transmit the matter for X-ray. The phenomenon is energy spectrum hardening. Thus, hadening correction has to be done. In this paper, not only is energy spectrum hardening analyzed by theory, but also the numerical analysis of precise accurate theory model for hardening correction of energy spectrum and theory method which has been presented in the literature and that observes to the law of Beer and the characteristics of X-ray internal material are reasoned out for X-ray TICT, which also is with reference to Simpson formula. Then, the attenuation coefficient that has been corrected is used for product back-projection reconstruction.Thus, the effect caused by X-ray beam hardening is wipped of effectively for X-ray TICT.-
Keywords:
- X-ray /
- TICT /
- Hardening correction /
- Simpson formula
-
-
[1] Barbara R Krohn, Michael D Silver. Optimizing contrast resolution in industrual computed tomographic scanners［J］. Materials Evaluation,1990,(10):1296-1331. [2] Rogerio Ferreira de Paiva, John Lynch, Elisabeth Rosenberg, et al. A beam hardening correction for X-ray microtomography［J］. NDT & International,1998,31(1):17-22. [3] 彭光含，杨学恒，韩 忠，等.连续谱X射线在ICT中的能谱硬化修正模型［J］.光谱学与光谱分析,2005,25(11):1880-1883. [4] 彭光含，杨学恒.X-ICT中连续谱服从Gauss分布的硬化修正研究［J］.无损检测,2005,27(11):565-568. [5] Hanke R, Bobel F. Determination of material flaw size by intensity evaluation of polychromatic X-ray transmission［J］. NDT & E International,1992,25(2):87. [6] Guy M J, Castellano-Smith I A, Flower M A, et al. Detect-dual engergy transmission estimation CT-for improved attenuation correction in SPECT and PET［J］. Ieee Transaction on Nuclear Science,1998,45(3):1261-1265. [7] 彭光含，杨学恒，辛洪政. X射线ICT中Compton散射效应的影响与散射修正［J］.无损检测,2004,26(7):336-338.
计量
- 文章访问数: 0
- HTML全文浏览量: 0
- PDF下载量: 0
下载:
