Comparison of Relaxivity and Image Quality of Brand name vs Generic Ferumoxytol: phantom and in vivo results

Motivation: Ferumoxytol is a superparamagnetic iron-oxide agent increasingly used for MR angiography. Cost can potentially be reduced by using a newly introduced generic ferumoxytol, so long as the relaxivity and image quality are similar. Goal(s): To compare the relaxivity and image quality of brand name ferumoxytol (Feraheme®, AMAG Pharmaceuticals) with generic ferumoxytol (Sandoz), and determine optimal dose and acquisition parameters. Approach: Phantom experiment and in-vivo dose accumulation with flip angle optimization, using an intra-individual cross-over design. Results: No clinically relevant differences in relaxivity and MR angiography image quality were observed between ferumoxytol agents. The optimal flip angle and dose are 20° and 5mg/kg, respectively. Impact: Brand name ferumoxytol (Feraheme®, AMAG Pharmaceuticals) and generic ferumoxytol (Sandoz) are interchangeable for MR angiography. The use of a generic agent may lead to reduction in cost.