Dark-field radiography, a new X-ray imaging method, has recently been applied to human chest imaging for the first time. It employs conventional X-ray devices in combination with a Talbot-Lau interferometer with a large field of view, providing both attenuation and dark-field radiographs. It is well known that sample scatter creates artifacts in both modalities. Here, we demonstrate that also X-ray scatter generated by the interferometer as well as detector crosstalk create artifacts in the dark-field radiographs, in addition to the expected loss of spatial resolution. We propose deconvolution-based correction methods for the induced artifacts. The kernel for detector crosstalk is measured and fitted to a model, while the kernel for scatter from the analyzer grating is calculated by a Monte-Carlo simulation. To correct for scatter from the sample, we adapt an algorithm used for scatter correction in conventional radiography. We validate the obtained corrections with a water phantom. Finally, we show the impact of detector crosstalk, scatter from the analyzer grating and scatter from the sample and their successful correction on dark-field images of a human thorax.

中文翻译：

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暗场射线照相中 X 射线散射和探测器串扰的校正


暗场摄影作为一种新的X射线成像方法，最近首次应用于人体胸部成像。它采用传统的 X 射线设备与大视场 Talbot-Lau 干涉仪相结合，提供衰减和暗场射线照片。众所周知，样本分散会在两种模式中产生伪影。在这里，我们证明，除了预期的空间分辨率损失之外，干涉仪产生的 X 射线散射以及探测器串扰也会在暗场射线照片中产生伪影。我们提出了基于反卷积的校正方法来校正引起的伪影。测量探测器串扰的内核并将其拟合到模型中，而分析仪光栅散射的内核则通过蒙特卡罗模拟计算。为了校正样本的散射，我们采用了传统放射线照相中用于散射校正的算法。我们用水模型验证所获得的校正。最后，我们展示了探测器串扰、分析仪光栅散射和样本散射的影响，以及它们对人体胸部暗场图像的成功校正。