Abstract
PURPOSE OF THE REPORT: Combined cardiac (68)Ga-Fibroblast-Activation Protein-alpha inhibitor (FAPI) positron-emission tomography (PET) and cardiac magnetic resonance imaging (MRI) constitute a novel diagnostic tool in patients for the assessment of myocardial damage after an acute myocardial infarction (AMI). Purpose of this pilot study was to evaluate simultaneous Ga-68-FAPI-46-PET/MR imaging in the delayed phase after AMI. MATERIAL AND METHODS: Eleven patients underwent hybrid (68)Ga-FAPI-46 PET/MRI post AMI. Standardized uptake values and fibroblast activation volume (FAV) were calculated and correlated with serum biomarkers and MRI parameters. RESULTS: Significant (68)Ga-FAPI-46 uptake could be demonstrated in 11 (100 %) patients after a mean period of 30.9 ± 22.0 days. FAV significantly exceeded the infarction size in MRI and showed a good correlation to MRI parameters as well as to serum biomarkers of myocardial damage. CONCLUSIONS: (68)Ga-FAPI-46 PET/MRI offers molecular and morphological imaging of affected myocardium after AMI. This study demonstrates ongoing fibroblast activation in a delayed phase after AMI and generates hypotheses for future studies while aiming for a better understanding of myocardial remodeling following ischemic tissue damage.