Dual Energy CT Imaging in Cone-Beam Micro-CT for Improved Attenuation Coefficient Measurement

In order to improve micro-CT＇s capability of accurate quantification of linear attenuation coefficient μ, a dual energy method was developed to correct beam hardening artifacts caused by the polychromatic spectra of X-ray tubes. In this method, two sets of scans, taken at different energy levels, we...

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Bibliographic Details
Published inTsinghua science and technology Vol. 16; no. 4; pp. 352 - 357
Main Author 唐智伟 胡广书
Format Journal Article
LanguageChinese
English
Published Elsevier Ltd 01.08.2011
Subjects
Attenuation coefficients
beam hardening
Beams (radiation)
cone-beam
CT成像
dual energy
Imaging
linear attenuation coefficient
Mathematical models
micro-CT
Polymethyl methacrylates
X-ray tubes
双能量
微型
测量
物理模型
线性衰减系数
聚甲基丙烯酸甲酯
锥束
cone-beam
micro-CT
beam hardening
dual energy
linear attenuation coefficient
Online AccessGet full text
ISSN1007-0214
1878-7606
1007-0214
DOI10.1016/S1007-0214(11)70051-7

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Summary:In order to improve micro-CT＇s capability of accurate quantification of linear attenuation coefficient μ, a dual energy method was developed to correct beam hardening artifacts caused by the polychromatic spectra of X-ray tubes. In this method, two sets of scans, taken at different energy levels, were combined to create a synthetic monochromatic image. A physical polychromatic model of μ in dual energy imaging was developed with an iterative method to solve the model for a few selected pixels. To find a high-speed and effective computing approach, the physics model was approximated by a polynomial function of the measured intensities. The method was tested on a PMMA-aluminum phantom and CaCI2 admixtures. The results show that streak and cupping artifacts are completely eliminated and that the measurement of the reconstructed attenuation coefficient μ is observed to be over 95% accurate.
Bibliography:11-3745/N
TANG Zhiwei , HU Guangshu Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China
In order to improve micro-CT＇s capability of accurate quantification of linear attenuation coefficient μ, a dual energy method was developed to correct beam hardening artifacts caused by the polychromatic spectra of X-ray tubes. In this method, two sets of scans, taken at different energy levels, were combined to create a synthetic monochromatic image. A physical polychromatic model of μ in dual energy imaging was developed with an iterative method to solve the model for a few selected pixels. To find a high-speed and effective computing approach, the physics model was approximated by a polynomial function of the measured intensities. The method was tested on a PMMA-aluminum phantom and CaCI2 admixtures. The results show that streak and cupping artifacts are completely eliminated and that the measurement of the reconstructed attenuation coefficient μ is observed to be over 95% accurate.
micro-CT; cone-beam; linear attenuation coefficient; beam hardening; dual energy
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content type line 23
ISSN:1007-0214
1878-7606
1007-0214
DOI:10.1016/S1007-0214(11)70051-7