Liu H, Karellas A, Harris L J, D'Orsi C J
Department of Radiology, University of Massachusetts Medical Center, Worcester 01655.
Med Phys. 1994 Jul;21(7):1193-5. doi: 10.1118/1.597352.
In lens-coupled CCD x-ray imaging, the lens efficiency is of critical importance for attaining an x-ray quantum-noise-limited system. However, the equations and the associated parameters of this process have not always been used properly in some of the literature. This can result in the incorrect estimation of the signal-to-noise ratio (SNR). In practice, it is found more convenient to use lens-coupling efficiency equations which assume that the scintillating screen is an extended Lambertian source, since the number of light photons emerging from various scintillating screens has been measured and reported by several investigators. This communication examines several of the most common types of lens-coupling efficiency equations and explains how to use them correctly with other parameters to calculate the SNR of a lens-coupled CCD x-ray imaging system.
在透镜耦合电荷耦合器件（CCD）X射线成像中，透镜效率对于实现X射线量子噪声限制系统至关重要。然而，在一些文献中，这个过程的方程和相关参数并未总是得到正确使用。这可能导致信噪比（SNR）的错误估计。在实际应用中，发现使用假设闪烁屏为扩展朗伯源的透镜耦合效率方程更为方便，因为已有几位研究者测量并报告了从各种闪烁屏出射的光光子数量。本文探讨了几种最常见的透镜耦合效率方程类型，并解释了如何将它们与其他参数正确结合使用，以计算透镜耦合CCD X射线成像系统的信噪比。
