Purpose To explore the characteristics and aging of IP. Materials and Methods The radiographic parameters were 70kV, 100mAs and 70 kV,200mAs,the distance between IP and the X-ray tube was 150cm. Placed aluminum,which would be increased from 1 to 28 pieces, between IP and X-ray tube, exposed under X-ray and scaned the IP by KODAK CR900, recorded the exposure indexs. Results The curve equation of the relationship between relative exposure dose and exposure index was y= 749.29 x+ 79. 048, R2 = 0. 9978 ,it was Linear. The curve equation of the relationship between the exposure dose and exposure index was y=324. 321n (x) +825.75,R2 =9 978,it was Logarithmic relationship. Conclusion IP feature is linear within a certain range. The fluorescent substance of IP imaging layer was gradual decrepit with the increasing time and frequency of use. With IP decrepit, it is necessary to increase exposure dose to achieve better result. The exposure index should be controlled between 1700～2700 to ensure the quality of CR image.%目的:探讨IP的特性及其老化情况.材料和方法:选择摄影条件70kV,距离150cm,在100mAs及200mAs两种曝光条件下,于IP与X球管之间分别放置1～28块铝片,在X线机下直接曝光,IP通过KODAK CR900扫描,分别记录曝光指数.结果:相对曝光量与曝光指数关系曲线方程为y＝749.29x+79.05,R2＝0.997 8,呈线性关系;曝光量与曝光指数关系曲线方程为y＝324.32ln(x)+825.75,R2=0.997 8,呈对数关系.结论:IP的特性是在一定的范围内是线性的;IP成像层的辉尽性荧光物质衰老是使用年限和使用频率的渐进过程;衰老的IP需增加曝光量才能达到开始使用时的效果,曝光指数有效范围应控制在1 700～2 700,CR图像质量才能得到保证.
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