title: High field magnetic resonance imaging evaluation of superparamagnetic iron oxide nanoparticles in a permanent rat myocardial infarction.
abstract: OBJECTIVE
  The purpose of this study was to evaluate superparamagnetic iron oxide (SPIO) nanoparticles to discriminate infarcted from normal tissue after myocardial infarction using high field MR imaging (7 tesla).
  
  
  METHODS
  Permanent myocardial infarction was induced in rats. SPIO nanoparticles (1 mg Fe/kg) were assessed with T1-weighted gradient echo sequence to visualize the myocardial infarction 48 hours after ligature (n = 6). Furthermore, MR Imaging was performed using a T2-weighted RARE sequence and nanoparticles were injected (5 or 10 mg Fe/kg) on 36 rats 5, 24 or 48 hours after infarction.
  
  
  RESULTS
  No changes in contrast between normal and infarcted myocardium was observed after nanoparticle injection on T1-weighted images. However, nanoparticles induced a significant contrast increase between normal and infarcted myocardium on T2-weighted images whatever the delay between infarction and imaging (2.99 +/- 1.66 preinjection vs. 7.82 +/- 1.96 after SPIO injection at a dose of 5 mg Fe/kg 5 hours postinfarction, P = 0.0001).
  
  
  CONCLUSIONS
  Nanoparticle injection made it possible to discriminate normal from infarcted myocardium on T2-weighted images. However, the high magnetic field prevented the visualization of the T1 effect of SPIO nanoparticles.
authors.affiliation: Inserm ERIT-M 0104, Ingénierie de la Vectorisation, Université d'Angers, France.
authors.forename: C
authors.initials: C
authors.lastname: Chapon
authors.forename: F
authors.initials: F
authors.lastname: Franconi
authors.forename: L
authors.initials: L
authors.lastname: Lemaire
authors.forename: L
authors.initials: L
authors.lastname: Marescaux
authors.forename: P
authors.initials: P
authors.lastname: Legras
authors.forename: J P
authors.initials: JP
authors.lastname: Saint-André
authors.forename: B
authors.initials: B
authors.lastname: Denizot
authors.forename: J-J
authors.initials: JJ
authors.lastname: Le Jeune
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005260:Female; D007501:Iron; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D009203:Myocardial Infarction / Q000175:diagnosis*; D036103:Nanotechnology; D010087:Oxides; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar
chemical_list: D010087:Oxides; D007501:Iron