Borasi G, Bregant P, Crespi A, De Denaro M, Ferretti P P, De Guarrini F, Levrero F, Mozzo P, Novario R, Pedroli G
Servizio di Fisica Sanitaria, Arcispedale Santa Maria Nuova, Reggio Emilia.
Radiol Med. 1993 May;85(5):662-7.
The comparative evaluation of radiographic screen-film systems presents several problems from both the theoretical and the experimental points of view. From the theoretical point of view the main difficulties are related to the choice of the parameters best suited to express the "overall quality" of a system. This quantity is expressed as a product of image quality index and system sensitivity. As image quality index we assumed the signal-to-noise power ratio: this index depends in an explicit way on contrast, resolution and noise of the system. From the experimental point of view the main problem is that to measure some basic quantities, sophisticated and expensive equipment, like computer-controlled microdensitometers, is generally required. In this paper, we report the Italian Association of Biomedical Physicists Task group suggestions for measuring the basic physical parameters (with particular reference to the use of cost-effective equipment and for purchasing specification drafting). Using synthetic quality indices, the evaluation criteria of radiographic materials are directly derived from the general theory of radiographic image perception.
从理论和实验的角度来看，对射线照相增感屏 - 胶片系统进行比较评估存在几个问题。从理论角度而言，主要困难在于选择最适合表达系统“整体质量”的参数。这个量表示为图像质量指数和系统灵敏度的乘积。作为图像质量指数，我们采用了信噪功率比：该指数以明确的方式取决于系统的对比度、分辨率和噪声。从实验角度来看，主要问题是测量一些基本量通常需要精密且昂贵的设备，如计算机控制的微密度计。在本文中，我们报告了意大利生物医学物理学家协会任务组关于测量基本物理参数的建议（特别提及使用性价比高的设备以及采购规格起草）。使用综合质量指数，射线照相材料的评估标准直接源自射线照相图像感知的一般理论。
