【作者】 周振杰； 吴金杰； 王玉龙； 杨扬； 任世伟；

【Author】 ZHOU Zhen-jie;WU Jin-jie;WANG Yu-long;REN Shi-wei;Hebei University Of Science and Tecnology;National Institute of Metrology;The south university;Chengdu university of technology;

【机构】 河北科技大学； 中国计量科学研究院；

【摘要】 目的建立4个CCRI推荐的钼靶X射线参考辐射质,得到的实验数据,参与国际计量局组织的乳腺X射线空气比释动能国际比关键比对项目(BIPM.RI(I)-K7)。建立钼靶X射线基准,填补国内空白,解决乳腺X射线诊断设备的量值溯源问题。方法使用经BIPM刻度过的RC6M平板型电离室,连接小电流测量系统,根据钼靶X射线规范,测得X射线经过不同厚度的衰减片后的电离电流值。然后利用origin作图软件对实验数据进行E指数拟合,得到各个规范的衰减曲线,插值法得到不同辐射质的半值层,并计算同质系数。根据质量衰减系数u/p和半值层的关系求得质量衰减系数,然后分段拟合得到NIST数据库中质量衰减系数和有效能量的曲线图,插值法得到各规范的有效能量。结果半值层测量结果与国际计量局BIPM参考值的相对偏差在1%以内,最大为0.82%,最小为0.32%,吻合较好,可以认为X射线辐射质基本相同。结论为建立乳腺X射线国家基准,开展国际比对和量值传递奠定了基础。更多还原

【Abstract】 Objective In oder to set up in the CCRI recommended molydenum target X-ray recommended reference radiation quality, and the experimental data takes participate in international organizations bureau of standard measurement of breast X-ray air kerma international than key comparison program(BIPM) RI(I)-K7).Establish molybdenum target X-ray benchmark, fill the domestic blank, solve the problem of quantity traceability of breast X-ray diagnostic equipment. Methods Use the calibrated RC6 M flat chamber by BIPM, connecting the small current measurement system, according to the molybdenum target X-ray standard specification, measured ionization current value of X-ray through different thickness of attenuation. Then using E index to fit experimental data by origin map wofware, and have various specifications of attenuation curves, the interpolation method to get different radiation half value layer, and calculate the coefficient of homogeneity.According to the mass attenuation coefficient of the u/p and half value layer obtained the relationship between mass attenuation coefficient, then the piecewise fitting to get the NIST database mass attenuation coefficient and effective energy diagram, the interpolation method to get the effective energy of each specification. ResultsHalf value layer measured results with the international BIPM reference bureau of standard measurement of relative deviation within 1%, the maximum is 0.82%, the minimum is 0.32%, it is in good agreement,and can be thought of X ray radiation are basically the same. ConclusionsTo establish breast X-ray national benchmark, international comparisons and dissemination laid a foundation.更多还原