Low-dose dual-energy cone beam CT material decomposition based on half-projection reconstruction:a feasibility study
10.3969/j.issn.1005-202X.2025.11.002
- VernacularTitle:基于半数投影的低剂量双能锥形束CT物质分解可行性
- Author:
Xinhui FU
1
;
Junfeng QI
;
Shutong YU
;
Lekang CHEN
;
Xuzhou WU
;
Tian LI
;
Chen LIN
;
Yibao ZHANG
Author Information
1. 北京大学医学部医学技术研究院,北京 100191
- Publication Type:Journal Article
- Keywords:
dual-energy imaging;
cone-beam CT;
image guidance;
low-dose imaging
- From:
Chinese Journal of Medical Physics
2025;42(11):1408-1413
- CountryChina
- Language:Chinese
-
Abstract:
Objective To propose and validate a decomposition method based on half-projection reconstruction for dual-energy cone beam CT(DE CBCT),thereby providing a potentially feasible low-dose imaging solution for anatomical monitoring and dose reconstruction optimization in adaptive radiotherapy.Methods Dual-energy scans were performed on a Gammex phantom using the on-board kilovoltage CBCT system of a VitalBeam accelerator at acquisition frame rates of 15 and 7 frames per second(f/s).Images were reconstructed from the projection data,and dual-energy decomposition was applied to the 7 f/s dual-energy images to derive relative electron density(RED)and stopping power ratio(SPR)using weighted formulas and empirical functions,followed by accuracy evaluation.Additionally,the weighted CT dose index was calculated for different scanning parameters.Results Dual-energy decomposition effectively suppressed image artifacts,with RED and SPR errors remaining below 2.82%and 2.56%,respectively.Compared with the traditional dual-scan method which required high-and low-energy acquisitions,the weighted CT dose index of the half-projection DE CBCT was reduced by 11.60 mGy(a 52.90%reduction).Furthermore,it was 2.58 mGy lower than the dose of the full-projection high-energy CBCT alone(a 19.98%reduction)and only 1.31 mGy higher than that of the low-energy CBCT(a 14.52%increase).Conclusion The proposed method effectively suppresses image artifacts while maintaining high accuracy in RED and SPR under low radiation dose conditions,demonstrating its potential value for scenarios requiring frequent image guidance,such as adaptive radiotherapy.
