Characterization of Blood Pool Half Life of USPIO Contrast Agent Ferumoxytol in Humans

Deqiang Qiu¹, Thomas Christen¹, Wendy W. Ni¹, Greg Zaharchuk¹, Michael E. Moseley¹

Ultra Small Paramagnetic Iron Oxide (USPIO) contrast agents have a strong T2* effect, which allows steady-state high-resolution quantitative Cerebral Blood Volume mapping (CBV) as well as enhanced sensitivity for fMRI based on CBV changes. We characterized the half-life of an FDA-approved USPIO compound ferumoxytol (AMAG Pharmaceuticals, Inc., Cambridge, MA) in humans. The R2* values of the brain before and after contrast injection as well as at follow-up sessions were obtained. The half-life of the contrast agent was estimated to range from 12.1 hours to 22.6 hours, longer than that measured in animal studies.