不同附加滤过组合对球管负荷和辐射剂量的影响

The influence of different additional filtration assemblies on X-ray tube load and radiation dose

目的:探讨不同附加滤过组合对球管负荷和辐射剂量的影响,旨在合理选择附加滤过组合,既能有效减少辐射剂量又不过分损耗X线球管。方法:以设备自带设定膝关节正位、腰椎正位和胸部正位摄影曝光模式,分别进行不同附加滤过组合[无附加滤过(A组)、2mm铝(B组)、0.1mm铜+2mm铝(C组)、0.2mm铜+2mm铝(D组)]对自制模体进行三组曝光,每组模式的曝光因子(除滤过组合外)相同,每个滤过组合进行5次曝光,记录每次曝光的曝光量(mAs)和剂量面积乘积(DAP)值,并进行统计学分析。结果:随着附加滤过厚度的增加,球管负荷随之增大;辐射剂量(DAP)随之减小;两两比较显示,球馆负荷(mAs值)D组>C组>B组>A组(P<0.001),辐射剂量(DAP值)D组<C组<B组<A组(P<0.001)。分析0.1mm铜+1mm铝与2mm铝的滤过效果,显示0.1mm铜比1mm铝的滤过能力更强(P<0.001)。结论:X线摄影时必须选择附加滤过,以0.2mm铜+2mm铝附加滤过效果最好,可以最大限度减少辐射剂量,但球管损伤也大,在实际工作中可灵活选择。

Objective：The purpose of this study was to investigate the effect of different additional filtering on X-ray tube load and radiation dose in order to select a reasonable assembly that could effectively reduce the radiation and not increase excessive wear of X-ray tube. Methods：A-P radiography of knee joint,lumbar,and chest of self-made molds was performed based on the built-in settings of the diagnostic X-ray source device by adding different filtering assemblies,0Al, 2mmAl,0. lmmCu＋2mmAl,and 0.2mmCu ＋ 2mmAl with other exposure parameters unchanged. A total of 5 exposures were performed under each assembly. The mAs and DPA value of each exposure were documented for statistical analysis. Results：With the increase of additional filtration thickness the tube load （mAs value） increased by 18. 063 %-88. 385 % and the radiation dose （DAP value） reduced by 11. 600% -55. 407 %. The results of single factor analysis of variance and pairwise comparison showed that the tube load （mAs value） was 0.2mmCu＋ lmmAl 〉 0. lmmCu＋ 1mmAl 〉 2mmAl〉0AI （P〈0. 001） ;the amount of radiation （DAP value） was 0.2mmCu＋ lmmAl 〈 0. 1mmCu＋ lmmAl 〈 2mmAl （P 〈0. 001）. The result of contrast analysis of 0. 1mmCu ＋1mmAl and 2mmAl indicated that the 0. lmmCu was better than lmmAl in filter capacity （P 〈 0. 001）. Conclusion：Additional filtration must be selected by users in radiography. The assembly of 0.2mmCu ＋ 2mmAl is of the best filtration effect. It can minimize the radiation dose but the wear is also noticeable, which provides as an alternative in practical work.