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

BackgroundThe 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.PurposeTo compare in vitro and in vivo MRI relaxometry and enhancement of Feraheme, generic ferumoxytol, and MoldayION.Study TypeProspective.Animal ModelTen healthy swine and six swine with artificially induced coronary narrowing underwent cardiac MRI.Field Strength/Sequence3.0 T; T1‐weighted (4D‐MUSIC, 3D‐VIBE, 2D‐MOLLI) and T2‐weighted (2D‐HASTE) sequences pre‐ and post‐contrast.AssessmentWe 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 TestsAnalysis of variance and covariance were used for group comparisons. A P value