FAPI Tracer en Vogue: Evaluating [68Ga]Ga-DATA5m.SA.FAPi for Molecular Imaging of Pulmonary Fibrosis

Figures

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  Figure 1. Longitudinal in vivo PET/CT imaging and quantitative analysis of BLM and control mice. Representative [68Ga]Ga-DATA5m.SA.FAPi PET/CT scans (coronal view) show the uptake of [68Ga]Ga-DATA5m.SA.FAPi in the lung, heart, liver, and thymus 4, 5, and 6 weeks following the initiation of weekly bleomycin injection (a). In vivo and ex vivo analysis of the respective organs (b) and quantification of body weight changes during disease progression (c). Data are expressed as the mean ± SEM, * p > 0.05, ** p > 0.01, %ID/cc = percentage injected dose per cubic centimeter, %ID/g = percentage injected dose per gram tissue.

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  Figure 2. Quantitative analysis of fra-2tg and WT mice using longitudinal in vivo PET/CT imaging. Representative [68Ga]Ga-DATA5m.SA.FAPi PET/CT scans (coronal view) demonstrate uptake of the tracer in the lung, heart, liver, and thymus at 7, 11, and 18/19 weeks of age (a). In vivo analysis expressed as SUV (g/mL) and %ID/cc, along with ex vivo analysis expressed as %ID/g (b), complemented by body weight changes over time (c). Data are expressed as the mean ± SEM, %ID/cc = percentage injected dose per cubic centimeter, %ID/g = percentage injected dose per gram tissue.

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  Figure 3. Histology and IHC supplemented with FAP expression analysis of BLM and control lungs. Hematoxylin/Eosin (HE), collagen staining (Sirius Red) (a), and FAP staining with corresponding expression analysis (b) of representative lungs from BLM and control mice at 4, 5, and 6 week measurement timepoints. The scale bar shown in the right bottom corner corresponds to 200 µm, * p > 0.05.

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  Figure 4. Pulmonary histology and immunohistochemistry (IHC) supplemented with fibroblast activation protein (FAP) expression analysis of fra-2tg and WT mice. Hematoxylin/Eosin (HE), collagen staining (Sirius Red) (a), and FAP staining with corresponding expression analysis (b) of representative lungs from fra-2tg and WT mice at 7, 11, and 18/19 weeks of age. Scale bar (bottom right) = 200 µm, **** p > 0.0001.