计算机X线摄影系统总特性曲线测试的探讨  

Study of overall characteristic curve measurement on a computed radiography system

作　　者：谢晋东[1] 魏世栋[2] 袁聿德[1] 王健[1] 张梦龙[1] 

机构地区：[1]山东泰山医学院放射系,泰安271000 [2]天津市第一中心医院放射科

出　　处：《中华放射学杂志》2002年第5期395-396,共2页Chinese Journal of Radiology

摘　　要：目的　测试计算机X线摄影 (computedradiography,CR)系统的总特性曲线。方法　利用常规X线机 ,采用时间阶段曝光法对成像板 (imagingplate,IP)曝光 ,经CR系统影像处理后 ,用密度计测量由激光打印在CR胶片上的不同密度楔的密度值并绘制特性曲线。结果　 (1)CR系统总特性曲线受层次处理的影响 ;(2 )旋转量 (rotationamount,GA)为 0 8、1 4、2 4时 ,总特性曲线平均斜率分别为 1 98、3 10、3 75。 (3)随GA值的变化 ,总特性曲线绕设定的旋转中心 (rotationcenter,GC)转动。结论　根据诊断的目的和肢体不同部位来选择GA值 ,可得到不同对比度的影像。Objective To test the overall characteristic curve on a computed radiography system. Methods Imaging plate was exposed by scale-time expose using conventional X-ray equipment. It was processed by CR system. Density of different optical density wedge on CR film was measured by using densimeter. Then, characteristic curve was plotted. Results (1) Overall characteristic curve of CR system was affected by gradation processing. (2) Average gradient of overall characteristic curve was 1.98, 3.10, and 3.75 when GA was 0.8,1.4, and 2.4. (3) Overall characteristic curve rotated around rotation center when rotation amount was changed. Conclusion According to the diagnostic purpose and different body position, rotation amount can be selected, and different contrast imaging can be acquired.

关 键 词：计算机X线摄影系统 总特性曲线 测试 

分 类 号：TH774[机械工程—仪器科学与技术]