Fig. 1

Bleomycin-treated mice present a higher uptake of [¹⁸F]FAPI-74 compared to control mice: Assessment of lung [¹⁸F]FAPI-74 uptake in control (white column bars) and bleomycin-treated (black column bars) mice at days 10 and 16 after instillation. Acquisitions were performed between 40 and 90 min after the radiotracer injection with subanalyses every 10 min. The lung uptake was respectively evaluated by the calculation of the mean standardized uptake value (SUVmean) (A-B) and the ratio between the uptake in lungs and the uptake in muscle (RLM) (C-D). Data are presented as mean with standard deviation and statistics analysis was performed using Two-Way ANOVA followed by Bonferroni correction test for multiple comparisons. E. Representative uptake of [¹⁸F]FAPI-74 at day 10 after instillation in a control (left) and a bleomycin-treated mice (right). F-H. Evaluation of the development of pulmonary fibrosis in bleomycin-treated mice (black column bars) compared to control mice (white column bars) at day 10 and 16 after instillation by the measurement of lung density (F), the Ashcroft modified scale (G) and the hydroxyproline (OH-proline) content of the right lung (H). Data are presented as mean with standard deviation and statistics analysis was performed using One-Way ANOVA followed by Holm-Sidak’s post-hoc test for multiple comparisons. I-K. Fibrosis parameters were correlated with the SUVmean obtained between 50 and 60 min after the radiotracer injection. The r corresponds to the Pearson coefficient for parametric correlation. Controls: n = 4–5; bleomycin-treated: n = 7–10. *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001