Enhancing contrast between sub-chronic myocardial infarct, remote and healthy myocardium using periodic irradiation...

Relaxations Along a Fictitious Field in the rotating frame of rank 2 (RAFF2) was used to characterize fibrosis-related myocardial diseases. RAFF2 can be sensitized to molecular dynamics processes by changing the durations of the RAFF2 pulses. Here, we studied the effect of altering the RAFF2 pulse durations for characterization of myocardial infarction (MI).

10 out of 13 mice hearts were harvested 7 days after occlusion coronary artery. We tested stretching factor (TL) between 0.6-2.0 with α₂ = 45°. The contrast between MI and remote areas were measured as Relative Relaxation Time Difference (RRTD).

Significant increase in relaxation time constants between MI and remote areas with relatively high RRTD were found in RAFF2 TL0.6, TL0.8, TL1.8 and TL2.0. With protein analysis, fibronectin was upregulated in MI area.

By altering durations RAFF2 pulse, the MI areas can be captured from the myocardium, which provides a novel way to evaluate molecular dynamics in the MI area. The findings were validated by the results of other MRI methods, protein analyses and histological sections.

Enhancement of MRI contrast between the MI, remote and healthy myocardium can be achieved by changing the duration RAFF2 pulse.