摘要
目的探讨通过优化小儿胸部数字化X线摄影的曝光参数,提高小儿摄影成像质量,减少小儿辐射剂量和重复摄影率。方法利用动物肺脏与X线衰减模体的不同厚度组合来模拟不同体厚的小儿,通过对模体、分辨率线队卡进行一系列曝光,kV值选择范围45~100 kV,采用自动曝光AEC、中野电离室曝光,记录各项参数。通过对曝光时间、曝光指数、辐射剂量以及图像分辨率制定出符合诊断要求的kV和mAs值。对来我院就诊的240名患儿分为2组,对照组采用设备厂家提供的曝光参数,观察组采用优化的曝光参数,比较图像质量和辐射剂量。结果不同厚度PMMA模体与动物肺脏组合后,分别与0~0.5、0.6~2、3~5、6~8岁儿童曝光参数接近。通过模体制定出符合不同年龄段曝光参数kV和mAs值。与对照组患儿相比,观察组患儿DR图像质量的评分及甲级片率均较高,其重复摄影率较低,辐射剂量值明显降低,其差异均具有统计学意义(P<0.05)。结论根据小儿年龄和体重的不同,制定不同的曝光参数是可行的,不但可以提高检查质量,而且可以有效降低小儿辐射剂量。
Objective To explore the exposure parameters of digital X-ray radiography(DR) by optimizing pediatric chest, improve the quality of pediatric photographic imaging, reduce radiation dose and repetition rate in children. Methods Different thickness combinations of lung and X-ray attenuation modes were used to simulate children with different body thickness. Through a series of exposure on the model body and resolution line card, the kV range was 45~100 kV, automatic exposure AEC and infield ionization chamber were adopted, and various parameters were recorded. Then the kV and mAs values that met the diagnostic requirements were determined by the exposure time, exposure index, radiation dose and image resolution. The 240 children who came to our hospital were divided into two groups. The exposure parameters provided by the equipment manufacturer were used in the control group, and the optimized exposure parameters were used in the observation group to compare the image quality and radiation dose. Results The exposure parameters of PMMA modules with different thickness were close to 0~0.5, 0.6~2, 3~5, 6~8 years old children. Then the kV and mAs values of exposure parameters were determined by the mode system. Compared with children in the control group, the quality of DR images in the observation group was higher than that of the first grade, the repeated photographic rate was lower, and the radiation dose(DAP) was significantly reduced. The difference was statistically significant(P<0.05). Conclusion It is feasible to establish different exposure parameters according to children's age and weight, which can not only improve the quality of inspection, but also reduce the radiation dose of children.
引文
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