Optimization of DXA lumber spine bone imaging parameters based on Monte Carlo method and CT voxel phantom
10.3760/cma.j.issn.0254-5098.2018.07.011
- VernacularTitle: 基于蒙特卡罗和CT数据体素模型的双能X射线吸收法腰椎骨密度成像参数优化
- Author:
Shi LI
1
;
Yifei PI
;
Wanli HUO
;
Zhi WANG
;
Zhi CHEN
;
Xie XU
Author Information
1. School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, China
- Publication Type:Journal Article
- Keywords:
Monte Carlo;
Computational voxel phantom;
Dual-energy X-ray;
Bone density imaging;
Imaging parameters optimization
- From:
Chinese Journal of Radiological Medicine and Protection
2018;38(7):541-546
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the lumber spine imaging process of dual-energy X-ray absorptiometry (DXA) and parameters used to optimize the image quality.
Methods:A computational voxel phantom was constructed from patient computed tomography (CT) data. Using the Monte Carlo radiation transport method, a dual energy x-ray beam was simulated to scan the phantom of lumbar spine to generate a bone density image. The Figure of Merit (FOM) of each image was claculated. Parameters including the combination of the high and low energy tube voltage, the thickness of Cu filter, and the ratio of two beam energy incident photon number were optimized, which based on FOM.
Results:FOM reaches a minimum of 1.59 × 10-2 with the tube voltage combination of 75 and 200 kVp. With the thickness of the Cu filter from 0 mm to 3 mm, FOM decreases from 6.30×10-2 to 1.87×10-2, showing a gradually slow-down trend. With the incident photon number ratio (low energy/high energy) increasing from 1∶3 to 19∶1, FOM decreases firstly and then increases, reaching a minimum of 1.40×10-2 at 3∶1.
Conclusions:According to the simulation results, the combinations of low tube voltage from 70 kVp to 85 kVp and high tube voltage from 160 kVp to 200 kVp, 0.3 mm Cu filter and beam incident photon number ratio from 1 to 5 can yield the best lumbar spine image quality with the lowest patient dose.
