Optimization-based image reconstruction regularized with inter-spectral structural similarity for limited-angle dual-energy cone-beam CT Journal Article


Authors: Peng, J.; Wang, T.; Xie, H.; Qiu, R. L. J.; Chang, C. W.; Roper, J.; Yu, D. S.; Tang, X.; Yang, X.
Article Title: Optimization-based image reconstruction regularized with inter-spectral structural similarity for limited-angle dual-energy cone-beam CT
Abstract: Objective. Limited-angle dual-energy (DE) cone-beam CT (CBCT) is considered as a potential solution to achieve fast and low-dose DE imaging on current CBCT scanners without hardware modification. However, its clinical implementations are hindered by the challenging image reconstruction from limited-angle projections. While optimization-based and deep learning-based methods have been proposed for image reconstruction, their utilization is limited by the requirement for x-ray spectra measurement or paired datasets for model training. This work aims to facilitate the clinical applications of fast and low-dose DE-CBCT by developing a practical solution for image reconstruction in limited-angle DE-CBCT. Approach. An inter-spectral structural similarity-based regularization was integrated into the iterative image reconstruction in limited-angle DE-CBCT. By enforcing the similarity between the DE images, limited-angle artifacts were efficiently reduced in the reconstructed DECBCT images. The proposed method was evaluated using two physical phantoms and three digital phantoms, demonstrating its efficacy in quantitative DECBCT imaging. Main results. In all the studies, the proposed method achieves accurate image reconstruction without visible residual artifacts from limited-angle DE-CBCT projection data. In the digital phantom studies, the proposed method reduces the mean-absolute-error from 309/290 HU to 14/20 HU, increases the peak signal-to-noise ratio from 40/39 dB to 70/67 dB, and improves the structural similarity index measurement from 0.74/0.72-1.00/1.00. Significance. The proposed method can efficiently reduce limited-angle artifacts during the image reconstruction, enabling quantitative DE-CBCT with comparable data acquisition time and radiation dose to that of a single-energy scan on current onboard scanners without hardware modification. This work is of great clinical significance and can boost the clinical application of DE-CBCT in image-guided radiation therapy and surgical interventions. © 2025 The Author(s). Published on behalf of Institute of Physics and Engineering in Medicine by IOP Publishing Ltd.
Keywords: radiotherapy; signal noise ratio; computerized tomography; medical imaging; phantoms, imaging; image processing, computer-assisted; image processing; image reconstruction; low dose; cone beam computed tomography; optimization; cone-beam computed tomography; phantoms; cone-beam ct; procedures; data acquisition; signal-to-noise ratio; structural similarity; imaging phantom; humans; human; iterative methods; dual-energy ct; structural optimization; hardware modifications; dual-energy; optimisations; images reconstruction; on currents; on-currents; reconstruction (structural); shape optimization
Journal Title: Physics in Medicine and Biology
Volume: 70
Issue: 14
ISSN: 0031-9155
Publisher: IOP Publishing Ltd  
Date Published: 2025-07-20
Start Page: 145010
Language: English
DOI: 10.1088/1361-6560/ade843
PUBMED: 40562072
PROVIDER: scopus
PMCID: PMC12246749
DOI/URL:
Notes: The MSK Cancer Center Support Grant (P30 CA008748) is acknowledged in the PubMed record and PDF -- Source: Scopus
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MSK Authors
  1. Tonghe Wang
    55 Wang
  2. Huiqiao Xie
    10 Xie