中国物理B ›› 2015, Vol. 24 ›› Issue (10): 108702-108702.doi: 10.1088/1674-1056/24/10/108702

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Investigation of noise properties in grating-based x-ray phase tomography with reverse projection method

鲍园a b, 王研b, 高昆a, 王志立a, 朱佩平a b, 吴自玉a b   

  1. a National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China;
    b Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China
  • 收稿日期:2015-02-13 修回日期:2015-04-24 出版日期:2015-10-05 发布日期:2015-10-05
  • 基金资助:

    Project supported by the National Basic Research Program of China (Grant No. 2012CB825800), the Science Fund for Creative Research Groups, the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos. KJCX2-YW-N42 and Y4545320Y2), the National Natural Science Foundation of China (Grant Nos. 11475170, 11205157, 11305173, 11205189, 11375225, 11321503, 11179004, and U1332109).

Investigation of noise properties in grating-based x-ray phase tomography with reverse projection method

Bao Yuan (鲍园)a b, Wang Yan (王研)b, Gao Kun (高昆)a, Wang Zhi-Li (王志立)a, Zhu Pei-Ping (朱佩平)a b, Wu Zi-Yu (吴自玉)a b   

  1. a National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, China;
    b Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China
  • Received:2015-02-13 Revised:2015-04-24 Online:2015-10-05 Published:2015-10-05
  • Contact: Bao Yuan, Zhu Pei-Ping E-mail:baoyuan@mail.ustc.edu.cn;zhupp@ihep.ac.cn
  • Supported by:

    Project supported by the National Basic Research Program of China (Grant No. 2012CB825800), the Science Fund for Creative Research Groups, the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant Nos. KJCX2-YW-N42 and Y4545320Y2), the National Natural Science Foundation of China (Grant Nos. 11475170, 11205157, 11305173, 11205189, 11375225, 11321503, 11179004, and U1332109).

摘要:

The relationship between noise variance and spatial resolution in grating-based x-ray phase computed tomography (PCT) imaging is investigated with reverse projection extraction method, and the noise variances of the reconstructed absorption coefficient and refractive index decrement are compared. For the differential phase contrast method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both theoretical analysis and simulations demonstrate that in PCT the noise variance of the reconstructed refractive index decrement scales with spatial resolution follows an inverse linear relationship at fixed slice thickness, while the noise variance of the reconstructed absorption coefficient conforms with the inverse cubic law. The results indicate that, for the same noise variance level, PCT imaging may enable higher spatial resolution than conventional absorption computed tomography (ACT), while ACT benefits more from degraded spatial resolution. This could be a useful guidance in imaging the inner structure of the sample in higher spatial resolution.

关键词: x-ray imaging, noise variance, spatial resolution, computed tomography (CT)

Abstract:

The relationship between noise variance and spatial resolution in grating-based x-ray phase computed tomography (PCT) imaging is investigated with reverse projection extraction method, and the noise variances of the reconstructed absorption coefficient and refractive index decrement are compared. For the differential phase contrast method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both theoretical analysis and simulations demonstrate that in PCT the noise variance of the reconstructed refractive index decrement scales with spatial resolution follows an inverse linear relationship at fixed slice thickness, while the noise variance of the reconstructed absorption coefficient conforms with the inverse cubic law. The results indicate that, for the same noise variance level, PCT imaging may enable higher spatial resolution than conventional absorption computed tomography (ACT), while ACT benefits more from degraded spatial resolution. This could be a useful guidance in imaging the inner structure of the sample in higher spatial resolution.

Key words: x-ray imaging, noise variance, spatial resolution, computed tomography (CT)

中图分类号:  (X-ray imaging)

  • 87.59.-e
42.30.Rx (Phase retrieval) 87.57.Q- (Computed tomography) 41.50.+h (X-ray beams and x-ray optics)