数字化X射线摄影设备(DR)曝光条件与剂量学参数相关性研究  

Correlations Between Exposure Conditions and Dosimetric Parameters for Digital Radiography(DR)

作　　者：曲良勇 高林峰[2] 姚杰[2] 钱爱君[2] 

机构地区：[1]上海中冶医院,上海200941 [2]上海市疾病预防控制中心,上海200336

出　　处：《中国辐射卫生》2010年第3期279-281,共3页Chinese Journal of Radiological Health

基　　金：上海市卫生局科研项目(2007177);上海市公共卫生优秀青年项目(08GWQ16)

摘　　要：目的研究数字X射线摄影设备曝光条件与剂量参数相关性。方法巴拉库达系统检测确认数字X射线摄影设备处于良好状态,在使用模体条件下,测试kV、mAs、过滤曝光等条件对剂量与面积之积(DAP)、输出量和入射体表剂量(ESD)等剂量参数的影响,分析曝光参数与剂量参数的相关性。结果从60 kV到120kV,DAP由173.80 mGy.cm2降低到33.39 mGy.cm2,X射线球管的输出量由0.010Gy/(A.s)增加到0.032 Gy/(A.s),ESD由0.74 mGy降低到0.17mGy。70kV、90 kV、110 kV条件下,DAP和ESD随mAs数的增加而呈逐渐增加趋势。在2.5mmAl+1mmCu或3.3 mmAl+1mmCu过滤条件下,DAP与ESD随管电压升高而降低的幅度明显小于采用3.3 mmAl或4.1 mmAl过滤时的情况。在过滤条件不变的情况下,数字X射线摄影机的剂量与面积之积、模体的入射体表剂量与kV曾明显的负相关(P<0.05),而与mAs呈明显的正相关(P<0.05);输出量与kV曾明显的正相关(P<0.05),而与mAs呈明显的负相关(P<0.05),这种相关性不受kV或mAs变化的影响。结论对于DR,适当提高kV条件,或降低mAs可有效降低受检者剂量。Objective To study correlations between exposure conditions and dosimetric parameters for digital radiography（DR）.Methods Quality assurance（QA） was performed with BARRACUDA system to make sure DR x-ray machine was in good condition.On condition that testing phantom was used,dosimetric parameters,such as dose area product（DAP）,output of x-ray machine,entrance surface dose（ESD） were recorded while changing exposure conditions including kV,mAs and filter.Correlations between exposure conditions and dosimetric parameters were analyzed.Rusults DAP reduced from 173.80 mGy·cm2 to 33.39 mGy·cm2,output of x-ray machine increased from 0.010Gy/（A·s） to 0.032 Gy/（A·s）,ESD reduced from 0.74 mGy to 0.17mGy,when kV raised steadily from 60 to 120.At 70kV,90 kV and 110 kV,DAP and ESD increased steadily in same trend as mAs.The decrease extent of DAP and ESD was distinctly less when 2.5 mmAl＋1mm Cu or 3.3mm Al＋1mm Cu were used as total filter,comparing to 3.3 mmAl or 4.1 mmAl.For certain filter,there were significantly negative correlation（P〈0.05） among DAP,ESD and kV,and there were significantly positive correlation（P〈0.05） among DAP,ESD and mAs.Output of x-ray machine was correlated positively negatively with kV（P〈0.05）,negatively with mAs（P〈0.05）.The correlations were not affected by changing of kV or mAs.Conclusion For DR,the dose of examinees can be effectively reduced by properly raising kV or lowering mAs.

关 键 词：数字化 X射线摄影 曝光条件 剂量 相关性 

分 类 号：R814.2[医药卫生—影像医学与核医学]