本文研究了双能X射线吸收法（DXA）成像过程并优化成像参数，为提高双能X射线骨密度仪的成像质量提供理论依据。采用蒙特卡洛方法，并构建基于患者计算机断层扫描影像数据（CT）的体素模型，利用模拟产生的高低能X射线能谱，分别照射体素模型腰椎部位得到骨密度图像。计算每幅图像的品质因数（FOM），FOM基于由探测器记录的X射线强度的量子统计特性导致的不确定性以及患者接受的辐射剂量，FOM值越小则优化程度越好。根据FOM优化高低能管电压组合、过滤铜片厚度以及入射强度比。结果表明，低能管电压75 kVp时，FOM最低，高能管电压在200 kVp以下时，高能管电压越高，FOM越低。随着铜片厚度增加，FOM下降并且下降趋势逐渐变缓。随着低能与高能的入射强度比增加，FOM先降低后升高。低能管电压为70~80 kVp，高能管电压为160~200 kVp，产生高能能谱时额外添加过滤铜片厚度0.3 mm，入射强度比值（低能/高能）为1~5时，能在获得较好的DXA图像质量的同时使患者受到较小的辐射剂量。
", "ds_source": "选取一名77岁男性的CT数据，编写MATLAB脚本，读取CT的DICOM文件，获取HU值。
", "ds_process_way": "采用蒙特卡罗模拟方法加工
", "ds_quality": "良好
", "ds_acq_start_time": "2017-01-01 00:00:00", "ds_acq_end_time": "2019-12-31 00:00:00", "ds_acq_place": "甘肃兰州", "ds_acq_lon_east": null, "ds_acq_lat_south": null, "ds_acq_lon_west": null, "ds_acq_lat_north": null, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "apply-access", "ds_total_size": 7670989, "ds_files_count": 2, "ds_format": "pdf", "ds_space_res": null, "ds_time_res": "", "ds_coordinate": "无", "ds_projection": "", "ds_thumbnail": "dad12afa-a2af-4c5e-9a8e-d5c27bf37332.png", "ds_thumb_from": 0, "ds_ref_way": "", "paper_ref_way": "", "ds_ref_instruction": "", "ds_from_station": null, "organization_id": "9971252d-7beb-4464-bc08-bdcc5a1d7dd1", "ds_serv_man": "敏玉芳", "ds_serv_phone": "0931-4967596", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "", "subject_codes": [], "quality_level": 3, "publish_time": "2023-11-27 10:23:30", "last_updated": "2023-11-27 10:23:30", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.NCDC.IMP.DB4087.2023", "i18n": { "en": { "title": "Parameter optimization of lumbar spine bone density imaging using dual-energy X-ray absorption based on Monte Carlo and CT data voxel model", "ds_format": "", "ds_source": "Select a 77 year old male CT data, write matlab script, read CT DICOM file, get hu value.
", "ds_quality": "good
", "ds_ref_way": "", "ds_abstract": "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.
", "ds_time_res": "", "ds_acq_place": "Lanzhou, Gansu", "ds_space_res": "", "ds_projection": "", "ds_process_way": "Monte Carlo simulation method is used for machining
", "ds_ref_instruction": "" } }, "submit_center_id": "ncdc", "data_level": 0, "recommendation_value": 0, "license_type": "https://creativecommons.org/licenses/by/4.0/", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "is_paper_in_submitting": false, "belong_to_nieer": false, "ds_topic_tags": [ "蒙特卡罗模拟", "计算机体素模型", "双能X射线", "骨密度城像", "城像参数优化" ], "ds_subject_tags": [], "ds_class_tags": [], "ds_locus_tags": [ "兰州", "甘肃省" ], "ds_time_tags": [ 2017, 2018 ], "ds_contributors": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "ds_meta_authors": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "ds_managers": [ { "true_name": "肖国青", "email": "xiaogq@impcas.ac.cn", "work_for": "中国科学院近代物理研究所", "country": "中国" } ], "category": "其他" }