Preliminary evaluation on the application of virtual monochromatic CT image in radiotherapy planning(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第8期
- Page:
- 966-970
- Research Field:
- 医学影像物理
- Publishing date:
Info
- Title:
- Preliminary evaluation on the application of virtual monochromatic CT image in radiotherapy planning
- Author(s):
- DU Bin; LI Xia; LIU Denghong; ZHU Zhihui; FU Yuchuan
- Department of Radiotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
- Keywords:
- Keywords: dual-energy CT gemstone spectral imaging monochromatic image radiotherapy planning
- PACS:
- R318
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.08.009
- Abstract:
- Abstract: Objective To analyze the characteristics of virtual monochromatic image obtained using gemstone spectral imaging mode, and to preliminarily evaluate the feasibility of application of virtual monochromatic image in the dose calculation of radiotherapy planning. Methods CIRS 062M electron density phantom was scanned with GE Revolution ES CT scanning system. The differences between measured CT number and theoretical values of different materials at different energies were analyzed. The CT numbers obtained in two scans with an interval of 26 days were compared. Finally, CT to electron density (ED) conversion curves for all monochrome images were established. Results The CT number of high-density materials changed significantly in the two scans under different monochromatic energies, while the CT number of materials with a density less than or equal to water changed little. For higher-density materials (such as Dense Bone 800), there was obvious difference between theoretical and measured CT numbers at lower energy. The CT-ED conversion curves from higher-energy virtual monochrome CT images had the same linear relationship as the multicolor image obtained in the normal mode but the CT-ED conversion curves from lower-energy virtual monochrome CT images were bilinear. Conclusion The bilinear CT-ED relationship may lead to errors in dose calculation. Therefore, the correct energy-related CT-ED conversion relationship must be selected when applying virtual monochromatic image to clinical dose calculation.
Last Update: 2021-07-31