# Bleomycin-induced lung fibrosis mouse model

In 22 C57BL/6 mice (11 given triple oropharyngeal bleomycin at 0.25 mg/kg to induce pulmonary fibrosis and 11 given saline), respiratory-gated µCT was acquired at baseline and days 7, 14, and 21, a U-Net deep-learning algorithm segmented the lungs into left and right lobes that were further divided into apical and caudal regions using airway landmarks for four subregions, and regional volumes, aeration compartments, and ventilation maps were extracted; saline-treated mice showed stable metrics with minimal interanimal variability, whereas bleomycin-treated animals showed early and heterogeneous fibrotic changes with the apical regions most affected and the caudal-right region displaying a compensatory functional increase, so that µCT-based regional analysis detected localized dysfunction a

In 22 C57BL/6 mice (11 given triple oropharyngeal bleomycin at 0.25 mg/kg to induce pulmonary fibrosis and 11 given saline), respiratory-gated µCT was acquired at baseline and days 7, 14, and 21, a U-Net deep-learning algorithm segmented the lungs into left and right lobes that were further divided into apical and caudal regions using airway landmarks for four subregions, and regional volumes, aeration compartments, and ventilation maps were extracted; saline-treated mice showed stable metrics with minimal interanimal variability, whereas bleomycin-treated animals showed early and heterogeneous fibrotic changes with the apical regions most affected and the caudal-right region displaying a compensatory functional increase, so that µCT-based regional analysis detected localized dysfunction a