Department of Physics, School of Natural Sciences, Technical University of Munich, 85748 Garching, Germany;
Munich Institute of Biomedical Engineering, Technical University of Munich, 85748 Garching, Germany.
Proc Natl Acad Sci U S A. 2022 Feb 22;119(8). doi: 10.1073/pnas.2118799119.
X-ray computed tomography (CT) is one of the most commonly used three-dimensional medical imaging modalities today. It has been refined over several decades, with the most recent innovations including dual-energy and spectral photon-counting technologies. Nevertheless, it has been discovered that wave-optical contrast mechanisms-beyond the presently used X-ray attenuation-offer the potential of complementary information, particularly on otherwise unresolved tissue microstructure. One such approach is dark-field imaging, which has recently been introduced and already demonstrated significantly improved radiological benefit in small-animal models, especially for lung diseases. Until now, however, dark-field CT could not yet be translated to the human scale and has been restricted to benchtop and small-animal systems, with scan durations of several minutes or more. This is mainly because the adaption and upscaling to the mechanical complexity, speed, and size of a human CT scanner so far remained an unsolved challenge. Here, we now report the successful integration of a Talbot-Lau interferometer into a clinical CT gantry and present dark-field CT results of a human-sized anthropomorphic body phantom, reconstructed from a single rotation scan performed in 1 s. Moreover, we present our key hardware and software solutions to the previously unsolved roadblocks, which so far have kept dark-field CT from being translated from the optical bench into a rapidly rotating CT gantry, with all its associated challenges like vibrations, continuous rotation, and large field of view. This development enables clinical dark-field CT studies with human patients in the near future.
X 射线计算机断层扫描（CT）是当今最常用的三维医学成像方式之一。它经过几十年的发展和完善，最近的创新包括双能和光谱光子计数技术。然而，人们发现，除了目前使用的 X 射线衰减之外，基于波动光学的对比机制具有提供补充信息的潜力，特别是对于其他无法解决的组织微观结构。一种这样的方法是暗场成像，它最近被引入，并且已经在小动物模型中显示出明显的放射学优势，特别是对于肺部疾病。然而，到目前为止，暗场 CT 还不能转化为人体规模，并且仅限于台式机和小动物系统，扫描时间为数分钟或更长时间。这主要是因为迄今为止，适应和扩展到人体 CT 扫描仪的机械复杂性、速度和尺寸仍然是一个未解决的挑战。在这里，我们现在报告了将泰伯-劳（Talbot-Lau）干涉仪成功集成到临床 CT 机中的情况，并展示了从单次 1 秒旋转扫描重建的人体大小的拟人体体模的暗场 CT 结果。此外，我们还提出了我们的关键硬件和软件解决方案，以解决以前未解决的障碍，这些障碍一直使暗场 CT 无法从光学平台转化为快速旋转的 CT 机，而后者存在振动、连续旋转和大视场等所有相关挑战。这一发展使得在不久的将来可以对人体患者进行临床暗场 CT 研究。
