距离法测试增感屏-胶片系统特性曲线的研究  

Study on characteristic curve of screen-film system using distance method

作　　者：谢晋东[1] 朱延好[1] 孙勇[1] 王健[1] 张梦龙[1] 

机构地区：[1]泰山医学院放射系,山东泰安271000

出　　处：《泰山医学院学报》2001年第1期12-14,共3页Journal of Taishan Medical College

摘　　要：目的　进一步探讨增感屏 胶片系统特性曲线距离测定法。方法　在焦点 胶片 40～ 40 0cm的距离范围内取 11个距离曝光点 ,在不同曝光条件下得到MSCaWO4/FujiRX及T颗粒两种屏 片体系光密度楔照片 ,绘制特性曲线。结果　 (1)T颗粒的平均斜率 2 7,MSCaWO4/FujiRX体系的平均斜率 2 4。 (2 )距离测定法的曝光条件取定在 6 0kV～ 80kV ,mAs以在距离 10 0 5cm[相对曝光量对数 (LogRE =1 2 ) ]时得到密度值 2 2为选取指标。结论　距离法最接近X线摄影实际 ,其测量参数更有指导意义 ,根据特性曲线使用的目的选取曝光点。Objective: To inquire into distance method of the characteristic curve for screen-film system. Methods: Under different exposure conditions, we selected eleven distance exposure points from 40 cm to 400cm between focus and film and made optical density step films for two types of screen-film system patterns (MS CaWO4/Fuji RX and T grain) and ploted characteristic curves. Results: (1) T grain average gradient was 27, MS CaWO4-Fuji RX system average gradient was 24. (2)Exposure conditions of distance method were set at 60～80 kV, mAs was selected based on the density of 22 on film acquired at the distance 1005 cm(LogRE=12). Conclusion: The distance method is most practically in accordance with X-ray radiological filming, its measured parameters have more directive function, and we can select distance exposure point according to the objective used characteristic curve.

关 键 词：X线摄影 距离法 特性曲线 增感屏-胶片系统 

分 类 号：R814.3[医药卫生—影像医学与核医学]