Positive Contrast MR imaging of in vivo atherosclerosis in a rabbit model using ultrasmall iron oxide particles
Mani V, Briley-Saebo K, Fayad Z, Hyafil F
Mount Sinai School of Medicine
Recent in-vitro studies using GRe Acquisition for Superparmagnmetic Particles (GRASP) sequence show that GRE sequences with manually controlled dephasing gradients resulted in positive signal enhancement in gels containing iron particles. The purpose of our study was to verify the in-vivo efficacy of GRASP to produce positive signal in plaques of atherosclerotic rabbits after administration of 4.7 mg Fe/kg USPIO (fractionated-Feridex). All imaging was performed at 1.5T using T2* GRE and GRASP sequences both pre and 24-hours post USPIO injection. The results of the study strongly suggest that GRASP sequence may be used to verify uptake of USPIO in plaque macrophages.