Ferumoxytol-enhanced three-dimensional magnetic resonance imaging of carotid atheroma- a feasibility and temporal dependence study

Abstract

ferumoxytol is an ultrasmall super paramagnetic particles of iron oxide (USpio) agent recently used for magnetic resonance (MR) vascular imaging. other USpios have been previously used for assessing inflammation within atheroma. We aim to assess feasibility of ferumoxytol in imaging carotid atheroma (with histological assessment); and the optimum MR imaging time to detect maximum quantitative signal change post-ferumoxytol infusion. ten patients with carotid artery disease underwent highresolution MR imaging of their carotid arteries on a 1.5 T MR system. MR imaging was performed before and at 24, 48, 72 and 96 hrs post ferumoxytol infusion. Optimal ferumoxytol uptake time was evaluated by quantitative relaxometry maps indicating the difference in T 2 * (Δt 2 *) and t 2 (Δt 2) between baseline and post-Ferumoxytol MR imaging using 3D DANTE MEFGRE qT 2 *w and iMSDE black-blood qt 2 w sequences respectively. 20 patients in total (10 symptomatic and 10 with asymptomatic carotid artery disease) had ferumoxytol-enhanced MR imaging at the optimal imaging window. 69 carotid MR imaging studies were completed. Ferumoxytol uptake (determined by a decrease in Δt 2 * and Δt 2) was identified in all carotid plaques (symptomatic and asymptomatic). Maximum quantitative decrease in Δt 2 * (10.4 [3.5-16.2] ms, p < 0.001) and Δt 2 (13.4 [6. 2-18.9] ms; p = 0.001) was found on carotid MR imaging at 48 hrs following the ferumoxytol infusion. Ferumoxytol uptake by carotid plaques was assessed by histopathological analysis of excised atheroma. ferumoxytol-enhanced MR imaging using quantitative 3D MR pulse sequences allows assessment of inflammation within carotid atheroma in symptomatic and asymptomatic patients. The optimum MR imaging time for carotid atheroma is 48 hrs after its administration.

Synthesis and Characterization of Citrate-Stabilized Gold-Coated Superparamagnetic Iron Oxide Nanoparticles for Biomedical Applications

“…Due to their magnetic properties, superparamagnetic iron oxide nanoparticles (SPIONs) are likewise promising for biomedical applications. Modification of their surface enables SPIONs to be used, e.g., as contrast agents in magnetic resonance imaging [ 19 , 20 ] or as drug delivery systems for the magnetic drug targeting of tumors and vascular injuries [ 21 , 22 , 23 ]. By combining the highly magnetic properties of SPIONs with an easy-to-functionalize gold surface, a fundamental hybrid carrier system (Au-SPIONs) can be generated [ 24 , 25 , 26 , 27 ], on which molecules designed for various medical applications can be attached.…”

MRI techniques for immunotherapy monitoring

“…94 Ferumoxytol (Feraheme) is an ultrasmall SPIO (17-30 nm) and an iron supplement approved by the Food and Drug Administration for the treatment of anemia in chronic kidney disease and has been used for imaging inflammatory atherosclerotic plaques. 96 This agent has been repurposed for the non-invasive detection of tumor-associated macrophages (TAMs) in both patients and preclinical models. [97][98][99][100] A decrease in ferumoxytol signal has been detected in MMTV-PyMT breast tumors depleted of macrophages following treatment with macrophage colony-stimulating factor 1 monoclonal antibodies.…”

Iron Oxide Nanoparticle Uptake in Mouse Brachiocephalic Artery Atherosclerotic Plaque Quantified by T2-Mapping MRI

“…Preclinical studies showed that it induces larger signal changes in the plaque than Sinerem [ 39 , 40 ]. Ferumoxytol has been used to image myocardial inflammation [ 41 , 42 ], and is being evaluated for monitoring inflammation in carotid atherosclerosis [ 20 , 22 , 43 ].…”