Delayed 68Ga-FAPI-46 PET/MR imaging confirms ongoing fibroblast activation in patients after acute myocardial infarction

Figures

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  Fig. 1. Representative set of images, showing radiotracer distribution of 68Ga-FAPI in axial images of PET/MRI. Tracer uptake shown in two STEMI patients (culprit lesion upper panel: RCX, lower panel: RCA) and two patients after NSTEMI (culprit lesion both panels: RCX); (N)STEMI, (Non)-ST-elevation myocardial infarction; SUV, standard uptake value; RCX, circumflex coronary artery; RCA, right coronary artery.

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  Fig. 2. PET parameter. (A) Uptake parameters for infarcted myocardium (FAV, cm3), bloodpool and remote myocardium. (B) Significant difference between tracer uptake volume (FAV) and volumetric infarct size in magnetic resonance imaging. SUV, standardized uptake value; FAV, fibroblast activation volume; ns, non-significant (p > 0.05); *p < 0.05, **p < 0.01, ****p < 0.0001.

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  Fig. 3. PET parameters stratified for STEMI and NSTEMI patients showing comparable results, with a tendency of higher FAV values in patients after STEMI. SUV, standardized uptake values; FAV, fibroblast activation volume; (N)STEMI, (non) ST-elevation myocardial infarction.

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  Fig. 4. Repeat FAP imaging in a patient after myocardial infarction. Case example for baseline and follow-up imaging. Baseline images show apical scar with moderate tracer uptake. Follow-up imaging demonstrates the persistence of the scar as well as aneurysmatic apical dilation with corresponding tracer uptake continuing up to 16 months after intervention. PET/MRI, positron-emission tomography/magnetic resonance imaging; FAPI, Fibroblast-Activation Protein-alpha inhibitor; MIP, maximum intensity projection; LGE, left gadolinium enhancement.