Comparison of Three Ultrasmall, Superparamagnetic Iron Oxide Nanoparticles for MRI at 3.0 T

Background The ultrasmall, superparamagnetic iron oxide (USPIO) nanoparticle ferumoxytol has unique applications in cardiac, vascular, and body magnetic resonance imaging (MRI) due to its long intravascular half‐life and suitability as a blood pool agent. However, limited availability and high cost have hindered its clinical adoption. A new ferumoxytol generic, and the emergence of MoldayION as an alternative USPIO, represent opportunities to expand the use of USPIO‐enhanced MRI techniques. Purpose To compare in vitro and in vivo MRI relaxometry and enhancement of Feraheme, generic ferumoxytol, and MoldayION. Study Type Prospective. Animal Model Ten healthy swine and six swine with artificially induced coronary narrowing underwent cardiac MRI. Field Strength/Sequence 3.0 T; T1‐weighted (4D‐MUSIC, 3D‐VIBE, 2D‐MOLLI) and T2‐weighted (2D‐HASTE) sequences pre‐ and post‐contrast. Assessment We compared the MRI relaxometry of Feraheme, generic ferumoxytol, and MoldayION using saline, plasma, and whole blood MRI phantoms with contrast concentrations from 0.26 mM to 2.10 mM. In‐vivo contrast effects on T1‐ and T2‐weighted sequences and fractional intravascular contrast distribution volume in myocardium, liver, and spleen were evaluated. Statistical Tests Analysis of variance and covariance were used for group comparisons. A P value