Superparamagnetic iron oxide: clinical application as a contrast agent for MR imaging of the liver.

TLDR

Superparamagnetic iron oxide (ferrite) particles were evaluated as a contrast agent for magnetic resonance imaging. The pilot study administered 10–50 µmol/kg ferrite intravenously to 15 patients. Ferrite‑enhanced liver MR images markedly increased lesion detection, lowered the detection threshold to 3 mm, and raised contrast‑to‑noise ratios, while early clearance after 12 h suggests low chronic toxicity and confirms that a 20 µmol/kg dose can substantially improve abdominal imaging.

Abstract

Superparamagnetic iron oxide (ferrite) particles were evaluated as a contrast agent for magnetic resonance (MR) imaging. In this pilot study, doses ranging from 10 to 50 mumol/kg were administered intravenously to 15 patients. Ferrite-enhanced images of the liver obtained with standard pulse sequence techniques significantly increased the number of hepatic lesions detected (P less than .01) and reduced the threshold size for detection to 3 mm (P less than .01). The improved clinical performance of ferrite-enhanced images correlated with significant increases in measured contrast-to-noise ratios (P less than .01). Degradation of superparamagnetic activity and/or clearance of ferrite from the liver was demonstrated as early as 12 hours after injection, suggesting that the lack of chronic toxicity observed in animal studies may be reproduced in humans. These initial clinical results appear to confirm extensive preclinical data indicating that ferrite administered at a dose of 20 mumol/kg has the potential to significantly improve the performance of abdominal MR imaging.