Background Chronic heart failure (CHF), as a result of acute myocardial infarction (AMI), is currently a leading cause of death worldwide. The direct assessment of novel treatments targeting CHF in vivo however remains difficult. While MRI can reveal cardiac morphology and tissue perfusion through the use of gadolinium (Gd) contrast agents, PET provides information on myocardial function at the molecular level. Here we present preliminary data using a combined 18FDG PET/MRI imaging system in an AMI mouse model with the aim of acquiring simultaneous morphological and functional data.
Methods An open-chest mouse (C57Bl/6J) heart model was utilised in which the left anterior descending coronary artery was occluded for 30 minutes to induce an ischaemic insult. A cardiac MRI with a 4.7T Bruker BioSpec system was performed 24 h after surgery. At 4 weeks post-AMI a second MRI was performed followed by a combined 18FDG PET-MRI investigation using the Cambridge split-magnet system.
Results Gd-enhanced MRI at 24 hr reperfusion revealed hyperenhancement of the infarcted region which corresponded to a signal void in the PET image obtained at 4 weeks post-MI. Furthermore, this was associated with a decrease in global ejection fraction as well as left ventricular wall thinning, consistent with the onset of heart failure.
Conclusion These preliminary findings demonstrate that the combined PET/MRI imaging system is a powerful tool in studying the pathophysiology of CHF allowing a better understanding of the progressive changes that occur and the direct evaluation of novel therapeutic treatments.