Dual-mode nanoparticle MRI contrast agents*

Contrast agents (CAs) can greatly improve the sensitivity and resolution in Magnetic Resonance Imaging (MRI). Various CAs are commercially available for both T1-weighted (e.g. gadolinium chelates) and T2-weighted (e.g. iron oxide nanoparticles) imaging. We have developed a series of CAs based on Fe and Mn oxo-metallic clusters encapsulated in polymer nanoparticles which display a large contrast enhancement for both T1- and T2- imaging. This creates the opportunity for dual-mode imaging combining T1- and T2- weighted images for enhanced sensitivity and resolution. We will discuss the synthesis of these materials and the development of image fusion algorithms for dual T1-T2 imaging.