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Deng S, Zhu Y, Zhang H, Wang Q, Zhu P, Zhang K, Zhang P. A method for material decomposition and quantification with grating based phase CT. PLoS One 2021; 16:e0245449. [PMID: 33481858 PMCID: PMC7822388 DOI: 10.1371/journal.pone.0245449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/31/2020] [Indexed: 12/20/2022] Open
Abstract
Material decomposition (MD) is an important application of computer tomography (CT). For phase contrast imaging, conventional MD methods are categorized into two types with respect to different operation sequences, i.e., “before” or “after” image reconstruction. Both categories come down to two-step methods, which have the problem of noise amplification. In this study, we incorporate both phase and absorption (PA) information into MD process, and correspondingly develop a simultaneous algebraic reconstruction technique (SART). The proposed method is referred to as phase & absorption material decomposition-SART (PAMD-SART). By iteratively solving an optimization problem, material composition and substance quantification are reconstructed directly from absorption and differential phase projections. Comparing with two-step MD, the proposed one-step method is superior in noise suppression and accurate decomposition. Numerical simulations and synchrotron radiation based experiments show that PAMD-SART outperforms the classical MD method (image-based and dual-energy CT iterative method), especially for the quantitative accuracy of material equivalent atomic number.
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Affiliation(s)
- Shiwo Deng
- School of Mathematical Sciences, Capital Normal University, Beijing, China
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
| | - Yining Zhu
- School of Mathematical Sciences, Capital Normal University, Beijing, China
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
| | - Huitao Zhang
- School of Mathematical Sciences, Capital Normal University, Beijing, China
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
- * E-mail:
| | - Qian Wang
- Department of Electrical and Computer Engineering, University of Massachusetts Lowell, Lowell, MA, United States of America
| | - Peiping Zhu
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Kai Zhang
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China
| | - Peng Zhang
- School of Mathematical Sciences, Capital Normal University, Beijing, China
- Beijing Advanced Innovation Center for Imaging Theory and Technology, Capital Normal University, Beijing, China
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Mechlem K, Sellerer T, Viermetz M, Herzen J, Pfeiffer F. Spectral Differential Phase Contrast X-Ray Radiography. IEEE TRANSACTIONS ON MEDICAL IMAGING 2020; 39:578-587. [PMID: 31380752 DOI: 10.1109/tmi.2019.2932450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We investigate the combination of two emerging X-ray imaging technologies, namely spectral imaging and differential phase contrast imaging. By acquiring spatially and temporally registered images with several different X-ray spectra, spectral imaging can exploit differences in the energy-dependent attenuation to generate material selective images. Differential phase contrast imaging uses an entirely different contrast generation mechanism: The phase shift that an X-ray wave exhibits when traversing an object. As both methods can determine the (projected) electron density, we propose a novel material decomposition algorithm that uses the spectral and the phase contrast information simultaneously. Numerical experiments show that the combination of these two imaging techniques benefits from the strengths of the individual methods while the weaknesses are mitigated: Quantitatively accurate basis material images are obtained and the noise level is strongly reduced, compared to conventional spectral X-ray imaging.
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Preliminary research on body composition measurement using X-ray phase contrast imaging. Phys Med 2018; 52:1-8. [PMID: 30139597 DOI: 10.1016/j.ejmp.2018.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/21/2018] [Accepted: 06/09/2018] [Indexed: 11/23/2022] Open
Abstract
Body composition measurement is of cardinal significance for medical and clinical applications. Currently, the dual-energy X-ray absorptiometry (DEXA) technique is widely applied for this measurement. In this study, we present a novel measurement method using the absorption and phase information obtained simultaneously from the X-ray grating-based interferometer (XGI). Rather than requiring two projection data sets with different X-ray energy spectra, with the proposed method, both the areal densities of the bone and the surrounding soft tissue can be acquired utilizing one projection data set. By using a human body phantom constructed to validate the proposed method, experimental results have shown that the compositions can be calculated with an improved accuracy comparing to the dual energy method, especially for the soft tissue measurement. Since the proposed method can be easily implemented on current XGI setup, it will greatly extend the applications of the XGI, and meanwhile has the potential to be an alternative to DEXA for human body composition measurement.
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