In fluoroscopic imaging, we can acquire x-ray image sequences using a flat-panel dynamic radiography detector. Because of the charge trapping at photodiodes, lag signals occur at the sequentially acquired images and produce lag artifacts. To design low-lag detectors, accurately measuring an amount of the lag signal is important. In the standard of IEC62220-1-3, a lag correction factor (LCF) is measured to obtain a true noise power spectrum, in which a temporal power spectral density (PSD) is employed using steady-state images. However, various noise signals can easily distort the PSD curve and cause erroneous measurements of LCF. In this letter, we propose a measurement algorithm for LCF using the correlation coefficients from steady-state images based on a linear lag model. This method can be a generalized version of a method that is based on the first-order regression model and has a characteristic that is resistant to various noises. Hence, for the standard, the proposed algorithm can be an alternative approach to the PSD method.

中文翻译：

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基于时间相关性的信号滞后测量

在透视成像中，我们可以使用平板动态射线照相探测器获取 X 射线图像序列。由于光电二极管中的电荷俘获，在顺序采集的图像中出现滞后信号并产生滞后伪影。为了设计低滞后检测器，准确测量滞后信号量很重要。在IEC62220-1-3标准中，测量滞后校正因子(LCF)以获得真实噪声功率谱，其中使用稳态图像采用时间功率谱密度(PSD)。然而，各种噪声信号很容易使 PSD 曲线失真并导致 LCF 的错误测量。在这封信中，我们提出了一种基于线性滞后模型的稳态图像相关系数的 LCF 测量算法。该方法可以是基于一阶回归模型的方法的推广版本，具有抗各种噪声的特性。因此，对于标准，所提出的算法可以是PSD方法的替代方法。