Nanoparticles as contrast agents for dark field imaging

Conventional radiological contrast agents augment x-ray attenuation to highlight tissues and features that may be difficult to visualize by conventional x-ray imaging. They are typically injected into the bloodstream, which can cause allergic reactions in at-risk populations. Dark-field x-ray imaging being sensitive to a material’s microstructure rather than its x-ray attenuation offers an alternative approach to contrast agents – the use of microscopically inhomogeneous materials as opposed to strongly absorbing ones. Here we demonstrate that nanoparticles can be used for this purpose.

“Fused” phase/dark-field image clearly showing the location of nanoparticles injected in a mouse liver. Concurrently, phase’s sensitivity to soft tissues enables the visualization of the surrounding organ.