Artificial Intelligence-Assisted Low-Dose High Atomic Number Contrast Agent for Ultrahigh-Resolution Computed Tomography Angiography.

Achieving high resolution while minimizing contrast agent dosage remains a key goal, yet a major challenge in contrast-enhanced computed tomography (CT) imaging. Herein, we propose an artificial intelligence-assisted low-dose high atomic number contrast agent for ultrahigh-resolution CT imaging. As a proof of concept, high-quality PEGylated hafnium oxide nanoparticles (DA-HfO2 NPs) are synthesized, exhibiting superior X-ray attenuation, high hafnium content (36%), excellent water solubility, appropriate hydrodynamic size (13.5 nm), and prolonged circulation half-life (161.9 min). High-dose DA-HfO2 NPs enable extended ultrahigh-resolution vascular imaging with a spatial resolution of 0.15 mm and a time window of at least 60 min. More importantly, by integrating artificial intelligence, the low-dose contrast agent (at 25% of the standard dose) achieves imaging quality comparable to that of the high-dose agent in both contrast density and spatial resolution, while simultaneously enhancing biosafety. This strategy enables high-resolution imaging at reduced contrast agent doses and offers a promising approach for sensitive and safe CT angiography.