Rationale and objectives: To investigate the capacity of manganese dipyridoxyl diphosphate (MnDPDP)-enhanced magnetic resonance imaging (MRI) to discriminate the injured myocardium from the normal myocardium in a cat model.
Materials and methods: Fourteen cats were prepared for acute myocardial infarction with 90-minute occlusion followed by 120-minute reperfusion. Inversion recovery gradient-recalled echo (IR-GRE) MR images were obtained at 60-minute intervals for 4 hours after the injection of MnDPDP, and ex vivo after the cats were killed. We evaluated the differences between the unenhanced area on the in vivo and ex vivo MR images and the unstained area on triphenyl tetrazolium chloride (TTC) staining.
Results: The unenhanced area on the in vivo MR images was well correlated with that on the ex vivo MR images. The unenhanced area on the ex vivo MR images was significantly larger than the unstained area on TTC staining.
Conclusions: This study suggests that the MnDPDP-unenhanced area on the MR images includes not only the infarcted myocardium but also the stunned myocardium.