A preclinical Talbot-Lau prototype for x-ray dark-field imaging of human-sized objects
A preclinical Talbot-Lau prototype for x-ray dark-field imaging of human-sized objects
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DOI：
10.1002/mp.12889
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发表时间：
2018-06-01
期刊：
影响因子：
3.8
通讯作者：
Hellbach, K.
中科院分区：
文献类型：
--
作者：
Hauke, C.;Bartl, P.;Hellbach, K.
目的：Talbot-Lau X射线干涉术除了提供物体的衰减特性外，还提供有关物体的散射和折射特性的信息。直到最近，这种方法还不适用于对人体大小的物体成像，因为要使Talbot-Lau干涉仪(TLI)适应相关的X射线能量范围是具有挑战性的。在这项工作中，我们提出了一个临床前的Talbot-Lau原型，能够在临床可接受的剂量水平上以适当的图像质量成像人类大小的对象。方法：TLI被设计为尽可能匹配临床相关性的设置。该系统通过使用扫描束几何结构提供120 x 30厘米(2)的扫描范围。它的极限载荷为100公斤。高纵横比和精细的栅格周期确保了合理的设置长度和临床相关的图像质量。该系统安装在一所大学医院，因此受到临床环境的外部影响。为了验证该系统的能力，对一只被安乐死的猪进行了全身扫描。结果：两种检查序列均获得了临床相关的图像质量--即使在皮肤入射空气比释动能仅为0.3mGY的情况下，也在人体胸部成像的范围内。一例气胸和一位读者的研究表明，样机的暗场图像为肺部诊断提供了额外的价值。结论：通过构建临床前的Talbot-Lau样机，我们证明了专门设计的Talbot-Lau干涉仪可以应用于医学成像。实验结果表明，该系统对人体大小的物体成像是可行的，分步成像方法适合于临床应用，因此Talbot-Lau X射线成像具有临床应用的潜力，提高了医用X射线成像的诊断能力。(C)2018年美国医学物理学家协会
Purpose: Talbot-Lau x-ray interferometry provides information about the scattering and refractive properties of an object - in addition to the object's attenuation features. Until recently, this method was ineligible for imaging human-sized objects as it is challenging to adapt Talbot-Lau interferometers (TLIs) to the relevant x-ray energy ranges. In this work, we present a preclinical Talbot-Lau prototype capable of imaging human-sized objects with proper image quality at clinically acceptable dose levels.Methods: The TLI is designed to match a setup of clinical relevance as closely as possible. The system provides a scan range of 120 x 30 cm(2) by using a scanning beam geometry. Its ultimate load is 100 kg. High aspect ratios and fine grid periods of the gratings ensure a reasonable setup length and clinically relevant image quality. The system is installed in a university hospital and is, therefore, exposed to the external influences of a clinical environment.To demonstrate the system's capabilities, a full-body scan of a euthanized pig was performed. In addition, freshly excised porcine lungs with an extrinsically provoked pneumothorax were mounted into a human thorax phantom and examined with the prototype.Results: Both examination sequences resulted in clinically relevant image quality - even in the case of a skin entrance air kerma of only 0.3 mGy which is in the range of human thoracic imaging. The presented case of a pneumothorax and a reader study showed that the prototype's dark-field images provide added value for pulmonary diagnosis.Conclusion: We demonstrated that a dedicated design of a Talbot-Lau interferometer can be applied to medical imaging by constructing a preclinical Talbot-Lau prototype. We experienced that the system is feasible for imaging human-sized objects and the phase-stepping approach is suitable for clinical practice.Hence, we conclude that Talbot-Lau x-ray imaging has potential for clinical use and enhances the diagnostic power of medical x-ray imaging. (c) 2018 American Association of Physicists in Medicine