Evaluation of [¹⁸F]FDG distribution and uptake via micro PET/CT in a murine model of myocardial infarction

Introduction: To evaluate [18F]Fluodeoxyglucose ([18F]FDG) distribution in a murine model of myocardial infarction (MI), using Positron Emission Tomography and Computed Tomography (PET/CT) to validate this approach for use in evaluating new therapies for MI treatment. Method: MI was induced by permanent ligation of the left anterior descending coronary artery. The study included a sham group, a group with 7 days infarction (acute infarction) and another with 21 days infarction (chronic infarction). Prior to euthanasia, each group was imaged by PET/CT approximately 60 minutes after injection of [18F]FDG. Total and maximal Region of Interest and Standard Uptake Value values were obtained using CT, which enables more precise delineation of the anatomy to assess between-group differences in [18F]FDG uptake in the heart, brain and bladder. Results: Following distribution of [18F]FDG throughout the body, at 60 minutes after injection homogeneous cardiac distribution of the radiopharmaceutical was observed in the healthy group, while in the infarcted groups there was an absence of uptake in the infarct area. Using ANOVA analysis and the Kruskal-Wallis test, statistically significant differences were detected between the healthy and acute infarction groups and the acute and chronic infarction groups. There were no significant differences between the three groups in brain uptake or radiopharmaceutical clearance. Conclusions: The microPET/CT technique has the sensitivity to detect infarcted areas in the murine model. Moreover, it allows us to quantify [18F]FDG uptake and thus assess uptake by the organs in the different groups studied.