Physics of Medical Imaging

Segmentation-free x-ray energy spectrum estimation for computed tomography using dual-energy material decomposition

[+] Author Affiliations
Wei Zhao

Huazhong University of Science and Technology, Department of Biomedical Engineering, Wuhan, China

Stanford University, Department of Radiation Oncology, Stanford, California, United States

Lei Xing

Stanford University, Department of Radiation Oncology, Stanford, California, United States

Qiude Zhang, Qingguo Xie

Huazhong University of Science and Technology, Department of Biomedical Engineering, Wuhan, China

Tianye Niu

Zhejiang University, School of Medicine, Sir Run Run Shaw Hospital and Institute of Translational Medicine, Hangzhou, China

J. Med. Imag. 4(2), 023506 (Jun 30, 2017). doi:10.1117/1.JMI.4.2.023506
History: Received November 8, 2016; Accepted June 9, 2017
Text Size: A A A

Abstract.  An x-ray energy spectrum plays an essential role in computed tomography (CT) imaging and related tasks. Because of the high photon flux of clinical CT scanners, most of the spectrum estimation methods are indirect and usually suffer from various limitations. In this study, we aim to provide a segmentation-free, indirect transmission measurement–based energy spectrum estimation method using dual-energy material decomposition. The general principle of this method is to minimize the quadratic error between the polychromatic forward projection and the raw projection to calibrate a set of unknown weights, which are used to express the unknown spectrum together with a set of model spectra. The polychromatic forward projection is performed using material-specific images, which are obtained using dual-energy material decomposition. The algorithm was evaluated using numerical simulations, experimental phantom data, and realistic patient data. The results show that the estimated spectrum matches the reference spectrum quite well and the method is robust. Extensive studies suggest that the method provides an accurate estimate of the CT spectrum without dedicated physical phantom and prolonged workflow. This paper may be attractive for CT dose calculation, artifacts reduction, polychromatic image reconstruction, and other spectrum-involved CT applications.

Figures in this Article
© 2017 Society of Photo-Optical Instrumentation Engineers

Citation

Wei Zhao ; Lei Xing ; Qiude Zhang ; Qingguo Xie and Tianye Niu
"Segmentation-free x-ray energy spectrum estimation for computed tomography using dual-energy material decomposition", J. Med. Imag. 4(2), 023506 (Jun 30, 2017). ; http://dx.doi.org/10.1117/1.JMI.4.2.023506


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

PubMed Articles
Advertisement


 

  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.