Barnes G T, Chakraborty D P
Radiology. 1982 Dec;145(3):815-21. doi: 10.1148/radiology.145.3.7146416.
Radiographic mottle has been analyzed in mammography using a comprehensive theory that takes into account fluctuations in absorbed x-ray energy and in phosphor light-photon yield, as well as film granularity and random variations in phosphor coating. Density fluctuations, signal-to-noise ratios, and quantum-efficiencies are presented for two screen/film systems as functions of density and viewing-aperture size. For sampling apertures of less than 500 micrometers in diameter, film granularity is the dominant source of noise for a Kodak Min-R screen/film system. This implies that quantum mottle can be increased and patient exposure reduced with little or no loss in imaged information. Such is the case for the second combination, a Min-R screen combined with Ortho-M film.
在乳腺摄影中，已使用一种综合理论对射线照相斑点进行了分析，该理论考虑了吸收的X射线能量和磷光光子产率的波动，以及胶片颗粒度和磷光体涂层的随机变化。给出了两种增感屏/胶片系统的密度波动、信噪比和量子效率与密度和观察孔径大小的函数关系。对于直径小于500微米的采样孔径，胶片颗粒度是柯达Min-R增感屏/胶片系统噪声的主要来源。这意味着可以增加量子斑点并减少患者辐射剂量，而图像信息几乎不会丢失。第二种组合情况就是如此，即Min-R增感屏与奥多-M胶片相结合。
