Wagner L K, Cohen G, Wong W H, Amtey S R
Med Phys. 1981 Jan-Feb;8(1):24-32. doi: 10.1118/1.594902.
The detail signal-to-noise ratio model of radiographic imaging is quantitatively analyzed in terms of its accuracy in describing observer threshold perceptibility of radiographic detail. The model is found to adequately describe the effects of magnification, scatter radiation, and system resolution on observer threshold perceptibility. However, it is shown that the model does not apply in screen/film radiography for very low contrasts and high scatter conditions due to insufficient optical density contrast. The dose-to-information conversion efficiency of a radiographic imaging system is defined and the effects of magnification, scatter, resolution, image processing, detector efficiency, grids, patient table support, field size, and geometry on the dose efficiency of the imaging system are investigated.
根据其在描述观察者对射线照相细节的阈值可感知性方面的准确性,对射线照相成像的详细信噪比模型进行了定量分析。发现该模型能够充分描述放大率、散射辐射和系统分辨率对观察者阈值可感知性的影响。然而,结果表明,由于光密度对比度不足,该模型不适用于极低对比度和高散射条件下的屏/片射线照相。定义了射线照相成像系统的剂量-信息转换效率,并研究了放大率、散射、分辨率、图像处理、探测器效率、滤线栅、病人检查床支撑、野大小和几何形状对成像系统剂量效率的影响。