Evaluation of nonperfused myocardial ischemia with MRI and an intravascular USPIO contrast agent in an ex vivo pig model

The ultrasmall superparamagnetic iron oxide (USPIO) preparation NC100150 In jection (Clariscan; Nycomed Imaging, Oslo, Norway) was tested for its abili ty to delineate nonperfused myocardium under steady-state conditions. An ex perimental animal model of focal myocardial ischemia induced by ligation of the distal part of the left anterior descending artery was used. The contr ast agent was administered in four doses: 0, 4, 8, and 12 mg Fe/kg body wei ght. Magnetic resonance examination ex vivo, including T1-, T2-, and T2*-we ighted sequences, was performed. Nonperfused myocardium was determined by f luorescein. The best delineation of nonperfused myocardium was found with a T1-weighted inversion recovery/turbo spin-echo sequence and doses of 4 and 8 mg Fe/kg body weight, where 95% of the volume was discernible at the dos e of 4 mg Fe/kg body weight. The results suggest that steady-state imaging by T1-weighted sequence with the use of NC100150 Injection to delineate non perfused myocardium is feasible. (C) 2000 Wiley-Liss, Inc.