This paper studies the imaging process of dual energy X-ray absorptiometry (DXA) and optimizes the imaging parameters, so as to provide a theoretical basis for improving the imaging quality of dual energy X-ray absorptiometry. Monte Carlo method was used to construct the voxel model based on the CT image data of patients. The simulated high-energy and low-energy X-ray energy spectrum was used to irradiate the lumbar vertebrae of the voxel model to obtain the bone mineral density image. The quality factor (FOM) of each image is calculated. Fom is based on the uncertainty caused by the quantum statistical characteristics of the X-ray intensity recorded by the detector and the radiation dose received by the patient. The smaller the FOM value, the better the degree of optimization. According to FOM, the voltage combination of high and low energy tubes, the thickness of filter copper and the incident intensity ratio are optimized. The results show that the FOM is the lowest when the low tube voltage is 75 kVp, and the higher the high tube voltage is, the lower the FOM is when the high tube voltage is below 200 kVp. With the increase of copper thickness, fom decreases and the decreasing trend becomes slow. As the incident intensity ratio of low energy to high energy increases, fom first decreases and then increases. Low energy tube voltage is 70 ~ 80 kVp, high energy tube voltage is 160 ~ 200 kVp. When the thickness of additional filter copper is 0.3 mm and the incident intensity ratio (low energy / high energy) is 1 ~ 5, good DXA image quality can be obtained and the patient can receive less radiation dose.
Select a 77 year old male CT data, write matlab script, read CT DICOM file, get hu value.
Monte Carlo simulation method is used for machining
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| # | number | name | type |
| 1 | 2017YFC0107500 | Research and implementation of a new conformal intensity modulation technique for multi-particle biology guided by multi-modes | National key R & D plan |
This work is licensed under
CC BY 4.0 (Creative Commons Attribution 4.0 International License).
CSTR:11738.11.NCDC.IMP.DB4087.2023
10.12072/ncdc.imp.db4087.2023
