Robson K J, Kotre C J, Faulkner K
Regional Medical Physics Department, Newcastle General Hospital, Newcastle upon Tyne, UK.
Br J Radiol. 1995 Mar;68(807):277-82. doi: 10.1259/0007-1285-68-807-277.
In mammography, it is important that the maximum amount of diagnostic information is obtained from each radiograph. One of the factors influencing image quality is the optical density of the film. In this study, a contrast-detail test object was used to establish the optimum optical density value on the basis of signal-to-noise ratio (SNR) for two mammographic film-screen combinations under particular processing conditions. The optimum optical density, taken as being the point at which the threshold contrast is a minimum varied little with detail size. The optimum optical density for the Fuji film-screen combination with Photosol chemistry was found to be higher than that for the Kodak film-screen combination and Kodak processing conditions studied. Although the actual values of optical density are specific to the fixed processing conditions encountered, the technique has more general applicability.
在乳腺X线摄影中，从每张射线照片中获取最大量的诊断信息非常重要。影响图像质量的因素之一是胶片的光学密度。在本研究中，使用了一个对比度细节测试物体，根据特定处理条件下两种乳腺X线胶片-增感屏组合的信噪比（SNR）来确定最佳光学密度值。最佳光学密度被视为阈值对比度最小的点，随细节尺寸变化不大。发现采用Photosol化学处理的富士胶片-增感屏组合的最佳光学密度高于所研究的柯达胶片-增感屏组合及柯达处理条件下的最佳光学密度。尽管光学密度的实际值特定于所遇到的固定处理条件，但该技术具有更广泛的适用性。
