High-Resolution MRI of SPIO-Labeled Yttrium Microsphere Biodistribution in the Rodent Liver at 7T

Weiguo Li¹, Zhuoli Zhang¹, Daniel Procissi¹, Andrew Gordon¹, Jodi Nicolai¹, Reed Omary¹, Andrew Larson¹

Radioembolization with Yttrium-90 (90Y) microspheres is a relatively new form of intra-arterial therapy for Hepatocellular carcinoma. However, visualization and quantification of 90Y microsphere biodistribution using conventional radiologic modalities is challenging. Whereas labeling 90Y microspheres with SPIOs offers the potential to use MRI to visualize in vivo biodistribution, optimization of the amount of SPIO included within these microspheres may be critical. In this study, we have demonstrated the potential to optimize SPIO content for future studies intended to quantify microsphere concentrations in vivo; we found that spheres with relatively low SPIO contents will be ideal candidates for future study.