目的研究射线成像系统中对比度与分辨率的关系．方法用线性系统理论分析狭缝图像通过系统调制传递函数后对比度所受到的影响．结果对单缝和多缝两种情况进行分析，得到了对比度与分辨率的关系．结论所获得的结果在对疵病尺寸进行定理检测时有重要意义． Objective To study the relationship between contrast and resolution in radiographic imaging system. Method The linear system theory was used to analyze the influence of the contrast of the slit image through the system modulation transfer function. The results of single-slit and multi-slit two cases were analyzed, the contrast and resolution of the relationship. Conclusion The results obtained are of great significance in the detection of the defect size.