采用儿童仿真模体研究胸部DR不同千伏照射下的有效剂量

目的采用1岁儿童仿真模体计算胸部数字化摄影(DR)不同千伏条件下儿童各组织、器官的吸收剂量,估算并比较不同千伏下有效剂量。方法塑料管分装的热释光剂量计(TLD)布放入儿童模体预留的插孔,在60、 70、80和90 kV时,自动曝光控制(AEC)模式下各曝光20次,然后回收TLD,回实验室测量。计算出不同千伏下组织、器官的吸收剂量,并分别估算出受照儿童模体全身有效剂量。结果在60、70、80和90 kV时照射野范围内各组织、器官随千伏的增高吸收剂量逐渐降低。4个实验组中有效剂量分别为0.43、0.34、0.29和0.23μSv。结论儿童模体胸部摄影使用较高千伏可减少组织、器官的吸收剂量和全身有效剂量。

Study on the effective dose of chest DR at different kilovolt conditions using children's anthropomorphic phantom

Objective The absorbed dose of tissues and organs of the 1-year old children under different kilovolt conditions was measured by anthropomorphic phantom, and the effective dose under different kilovolt conditions was estimated and compared.Methods The thermoluminescence dosimeter (TLD) assembled in the plastic tube was placed into the socket reserved for the anthropomorphic phantom of children, and exposed 20 times at 60, 70, 80 and 90 kV respectively in the automatic exposure control (AEC) mode, then the TLD was recovered and measured in the laboratory. The absorbed dose of tissues and organs under different kilovolt conditions was calculated and the effective dose of children was estimated respectively.Results The absorbed dose of all tissues and organs in the radiation field decreases gradually with the increase of kilovolt at 60, 70, 80 and 90kV.The effective doses in the 4 experimental groups were 0.43, 0.34, 0.29 and 0.23 μSv respectively.Conclusion The use of higher kilovolt radiography in the chest of infants can reduce the absorbed dose of tissues and organs and the effective dose of the whole body.