title: In vivo characterization of rodent cyclic myocardial perfusion variation at rest and during adenosine-induced stress using cine-ASL cardiovascular magnetic resonance.
abstract: BACKGROUND
  Assessment of cyclic myocardial blood flow (MBF) variations can be an interesting addition to the characterization of microvascular function and its alterations. To date, totally non-invasive in vivo methods with this capability are still lacking. As an original technique, a cine arterial spin labeling (ASL) cardiovascular magnetic resonance approach is demonstrated to be able to produce dynamic MBF maps across the cardiac cycle in rats.
  
  
  METHODS
  High-resolution MBF maps in left ventricular myocardium were computed from steady-state perfusion-dependent gradient-echo cine images produced by the cine-ASL sequence. Cyclic changes of MBF over the entire cardiac cycle in seven normal rats were analyzed quantitatively every 6 ms at rest and during adenosine-induced stress.
  
  
  RESULTS
  The study showed a significant MBF increase from end-systole (ES) to end-diastole (ED) in both physiological states. Mean MBF over the cardiac cycle within the group was 5.5 ± 0.6 mL g(-1) min(-1) at rest (MBFMin = 4.7 ± 0.8 at ES and MBFMax = 6.5 ± 0.6 mL g(-1) min(-1) at ED, P = 0.0007). Mean MBF during adenosine-induced stress was 12.8 ± 0.7mL g(-1) min(-1) (MBFMin = 11.7±1.0 at ES and MBFMax = 14.2 ± 0.7 mL g(-1) min(-1) at ED, P = 0.0007). MBF percentage relative variations were significantly different with 27.2 ± 9.3% at rest and 17.8 ± 7.1% during adenosine stress (P = 0.014). The dynamic analysis also showed a time shift of peak MBF within the cardiac cycle during stress.
  
  
  CONCLUSIONS
  The cyclic change of myocardial perfusion was examined by mapping MBF with a steady-pulsed ASL approach. Dynamic MBF maps were obtained with high spatial and temporal resolution (6 ms) demonstrating the feasibility of non-invasively mapping cyclic myocardial perfusion variation at rest and during adenosine stress. In a pathological context, detailed assessment of coronary responses to infused vasodilators may give valuable complementary information on microvascular functional defects in disease models.
authors.forename: Thomas
authors.initials: T
authors.lastname: Troalen
authors.forename: Thibaut
authors.initials: T
authors.lastname: Capron
authors.forename: Monique
authors.initials: M
authors.lastname: Bernard
authors.affiliation: Aix-Marseille Université, CNRS, CRMBM UMR 7339, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France. frank.kober@univ-amu.fr.
authors.forename: Frank
authors.initials: F
authors.lastname: Kober
mesh_terms: D000241:Adenosine; D000818:Animals; D003326:Coronary Circulation; D003971:Diastole; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D019028:Magnetic Resonance Imaging, Cine; D008833:Microcirculation; D023421:Models, Animal; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011673:Pulsatile Flow; D051381:Rats; D017208:Rats, Wistar; D013599:Systole; D013997:Time Factors; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D000241:Adenosine