Fig. 3.

Follow-up observations of SSc-MF patients. Representative images of [⁶⁸Ga]Ga-FAPI-04-PET-CT scan and the corresponding cMRI with late gadolinium enhancement (LGE) and T-mapping at baseline (BL) and follow-up (FU). Clinical findings including serum Nt-pro-BNP levels, ejection fraction (EF, %), and ECG findings are tabulated. A Reduction of [⁶⁸Ga]Ga-FAPI-tracer uptake upon start of medical therapy in a patient with pronounced tracer uptake at baseline, stable LGE, and minor changes of T1 relaxation times (participant 13). B Progressive [⁶⁸Ga]Ga-FAPI-04 tracer uptake and clinical deterioration with increased NT-pro-BNP levels and new onset of atrial fibrillation on follow op despite therapy (participant 10). The follow-up investigations of participants 11 and 14 are visualized in supplementary Fig. 6