FAPI PET Imaging Supports Clinical Decision Making in Academic Cardiology Practice

A dvances in nuclear cardiology molecular imaging improve decision making in clinical cardiology.Fibroblast activation protein alpha (FAP) is a homodimeric membrane-bound serine protease with intracellular and extracellular soluble forms.Positron emission tomography (PET) imaging using radiolabeled fibroblast activation protein alpha inhibitors (FAPIs) has emerged as a promising molecular imaging tool for oncology but also cardiology, possibly providing new insights into the pathophysiology of diseases.FAP is specifically expressed by early-stage activated fibroblasts during wound healing and cardiac remodeling.Therefore, FAPI PET provides a unique opportunity to visualize and quantify cardiac fibrosis, a key pathophysiological process involved in several cardiovascular diseases.Hence, this imaging modality is a powerful tool that can aid in clinical decision making.The complete potential of FAPI PET in nuclear cardiology has not been recognized fully to date.The purpose of this pictorial imaging vignette is to demonstrate potential applications of this modality in understanding the pathophysiologic aspects of common and rare myocardial diseases. STRUCTURE OF IMAGING VIGNETTEPET/computed tomography (CT) or PET/magnetic resonance imaging (MRI) was performed using 68 Ga-labeled Ga]Ga-FAPI-46) according to our established imaging protocols (administered activities and imaging delays are provided in Figures 1 to 10).Images are presented from top to bottom clockwise (when applicable) as follows: [ 68 Ga]Ga-FAPI-46 PET maximum-intensity projection (anterior view), myocardial 3-dimensional rendering, bull's-eye representation, and multiplanar reconstructions (transversal and sagittal view); CT/MRI transversal and sagittal view; PET/CT or PET/MRI fusion transversal and sagittal view; and echocardiography parasternal long axis and apical 4-chamber view.If available, other patient-specific molecular imaging modalities are supplemented.