基于动物模型的石膏固定后四肢摄影参数的优化  

Optimization of Photographic Parameters for Limbs with Plaster Cast Based on Animal Model

作　　者：徐子军[1] 王鸣鹏[2] 冯月华[1] 汤欢[1] 张长宝 徐彧 张宗锐[1] 

机构地区：[1]上海市第十人民医院放射科 [2]复旦大学附属华东医院放射科 [3]福建省泉州市泉港区医院放射科

出　　处：《中国医学计算机成像杂志》2017年第3期283-286,共4页Chinese Computed Medical Imaging

摘　　要：目的:研究石膏固定后的四肢摄影的优化方案。方法:依据自动曝光控制系统(AEC)开关分两组实验,每组管电压选择45~69kV,每2kV为一档,共11档,分别使用7档m As曝光;评价图像质量及辐射剂量,得出优化的摄影参数,应用于石膏固定后的猪后肢摄影。结果:石膏固定前,随kV值升高,AEC关闭组较AEC打开组图像质量更好;m As较kV对于信号噪声比(SNR)和对比噪声比(CNR)影响不明显。石膏固定后,SNR、CNR平均为24.25、1.7,较石膏固定前的24.9、2.15均降低。摄影参数优化后,SNR和CNR值平均升高为25.45和2.25,且DAP值降低。结论:四肢石膏固定后摄影中,适当提高管电压(建议5~8kV),关闭AEC,可获得更好影像质量的图像,并有效降低受检者的辐射剂量。Purpose： To study the optimization scheme of photography for limbs with plaster cast. Methods： Based on whether the automatic exposure control （AEC） was on or off, the experiments were divided into 2 groups. The exposure parameters in each group were set as 11 different kVs （ranged from 45 to 69 kV）, and 7 different mAs. The image quality and radiation dose were measured. The parameters of photography were optimized and applied to the photography of pig hind legs with piaster cast. Results： Without a piaster cast, when the kV value increased, the image quality of AEC on group was better than that of the AEC off group; The kV made more effect on the signal to noise ratio （SNR） and contrast to noise ratio （CNR） than mAs did. With a plaster cast, the SNR, CNR were 24.25 and 1.7, which were lower than that without a plaster cast （24.9, 2.15）. After the parameters were optimized, the SNR and CNR were 25.45 and 2.25, and the DAP value was lower. Conclusion： For limbs with a plaster cast, increase the tube voltage （suggest 5-8 kV） and turn offthe AEC, can obtain better image quality, and effectively reduce the radiation dose.

关 键 词：辐射剂量 信噪比 对比度噪声比 图像质量 

分 类 号：R-332[医药卫生] R814