Simard, Mikaël;
Bouchard, Hugo;
(2022)
One-step iterative reconstruction approach based on eigentissue decomposition for spectral photon-counting computed tomography.
Journal of Medical Imaging
, 9
(4)
, Article 044003. 10.1117/1.JMI.9.4.044003.
Preview |
PDF
044003_1.pdf - Published Version Download (6MB) | Preview |
Abstract
Purpose: We propose a one-step tissue characterization method for spectral photon-counting computed tomography (SPCCT) using eigentissue decomposition (ETD), tailored for highly accurate human tissue characterization in radiotherapy. Methods: The approach combines a Poisson likelihood, a spatial prior, and a quantitative prior constraining eigentissue fractions based on expected values for tabulated tissues. There are two regularization parameters: α for the quantitative prior, and β for the spatial prior. The approach is validated in a realistic simulation environment for SPCCT. The impact of α and β is evaluated on a virtual phantom. The framework is tested on a virtual patient and compared with two sinogram-based two-step methods [using respectively filtered backprojection (FBP) and an iterative method for the second step] and a post-reconstruction approach with the same quantitative prior. All methods use ETD. Results: Optimal performance with respect to bias or RMSE is achieved with different combinations of α and β on the cylindrical phantom. Evaluated in tissues of the virtual patient, the one-step framework outperforms two-step and post-reconstruction approaches to quantify proton-stopping power (SPR). The mean absolute bias on the SPR is 0.6% (two-step FBP), 0.6% (two-step iterative), 0.6% (post-reconstruction), and 0.2% (one-step optimized for low bias). Following the same order, the RMSE on the SPR is 13.3%, 2.5%, 3.2%, and 1.5%. Conclusions: Accurate and precise characterization with ETD can be achieved with noisy SPCCT data without the need to rely on post-reconstruction methods. The one-step framework is more accurate and precise than two-step methods for human tissue characterization.
| Type: | Article |
|---|---|
| Title: | One-step iterative reconstruction approach based on eigentissue decomposition for spectral photon-counting computed tomography |
| Location: | United States |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1117/1.JMI.9.4.044003 |
| Publisher version: | https://doi.org/10.1117/1.JMI.9.4.044003 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | eigentissue decomposition, one-step reconstruction, quantitative imaging, radiotherapy, spectral photon-counting computed tomography, tissue characterization |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10153383 |
Archive Staff Only
 |
View Item |
