Schmid Clemens, Viermetz Manuel, Gustschin Nikolai, Noichl Wolfgang, Haeusele Jakob, Lasser Tobias, Koehler Thomas, Pfeiffer Franz
IEEE Trans Med Imaging. 2023 Mar;42(3):774-784. doi: 10.1109/TMI.2022.3217662. Epub 2023 Mar 2.
X-ray computed tomography (CT) is an invaluable imaging technique for non-invasive medical diagnosis. However, for soft tissue in the human body the difference in attenuation is inherently small. Grating-based X-ray phase-contrast is a relatively novel imaging method which detects additional interaction mechanisms between photons and matter, namely refraction and small-angle scattering, to generate additional images with different contrast. The experimental setup involves a Talbot-Lau interferometer whose susceptibility to mechanical vibrations hindered acquisition schemes suitable for clinical routine in the past. We present a processing pipeline to identify spatially and temporally variable fluctuations occurring in an interferometer installed on a continuously rotating clinical CT gantry. The correlations of the vibrations in the modular grating setup are exploited to identify a small number of relevant fluctuation modes, allowing for a sample reconstruction free of vibration artifacts.
X射线计算机断层扫描（CT）是一种用于无创医学诊断的宝贵成像技术。然而，对于人体软组织来说，衰减差异本质上很小。基于光栅的X射线相衬成像法是一种相对新颖的成像方法，它能检测光子与物质之间额外的相互作用机制，即折射和小角散射，以生成具有不同对比度的额外图像。实验装置包括一个Talbot-Lau干涉仪，其对机械振动的敏感性在过去阻碍了适用于临床常规的采集方案。我们提出了一种处理流程，用于识别安装在连续旋转的临床CT机架上的干涉仪中发生的空间和时间上可变的波动。利用模块化光栅装置中振动的相关性来识别少量相关的波动模式，从而实现无振动伪影的样本重建。
