Navarrete-León Carlos, Doherty Adam, Strimaite Margarita, Bear Joseph C, Olivo Alessandro, Endrizzi Marco, Patrick P Stephen
Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, United Kingdom.
X-ray microscopy and tomography lab, The Francis Crick Institute, London, NW1 1AT, United Kingdom.
Nano Lett. 2025 Jan 22;25(3):1036-1042. doi: 10.1021/acs.nanolett.4c04878. Epub 2024 Nov 27.
The poor soft tissue contrast of X-ray CT necessitates contrast agent use to improve diagnosis across disease applications, yet their poor detection sensitivity requires high injected doses, which restrict use in at-risk populations. Dark-field X-ray imaging is emerging as a more sensitive alternative to traditional attenuation-based imaging, leveraging scattered radiation to produce contrast. Yet aside from large, short-lived microbubbles, the alternate physics of dark-field detection has yet to be exploited for contrast agent development. Here we demonstrate that high-Z nanoparticles can provide a new means to producing dark-field image contrast, promoting scatter via a higher rather than lower electron density compared to microbubbles, increasing detection sensitivity compared to attenuation-based detection of a clinical iodine-based agent at an equivalent X-ray dose. As the use of dark-field X-ray imaging expands into more common clinical usage, this will support the development of a new class of nanoparticulate contrast agents.
X射线CT的软组织对比度较差，因此需要使用造影剂来改善各种疾病应用中的诊断效果，然而其检测灵敏度较低，需要高注射剂量，这限制了其在高危人群中的使用。暗场X射线成像作为传统基于衰减成像的一种更灵敏的替代方法正在兴起，它利用散射辐射来产生对比度。然而，除了大的、寿命短的微泡外，暗场检测的替代物理原理尚未用于造影剂开发。在这里，我们证明高Z值纳米颗粒可以提供一种产生暗场图像对比度的新方法，与微泡相比，通过更高而非更低的电子密度促进散射，在相同X射线剂量下，与基于衰减的临床碘基造影剂检测相比，提高了检测灵敏度。随着暗场X射线成像在更常见的临床应用中的扩展，这将支持一类新型纳米颗粒造影剂的开发。
