Unilateral Lung Volume Analysis Using Micro-CT for Enhanced Assessment of Pulmonary Fibrosis in Preclinical Models

Pulmonary fibrosis (PF) is a progressive and irreversible interstitial lung disease characterized by poor prognosis and limited treatment options. The traditional mouse model of pulmonary fibrosis induced by intratracheal instillation of bleomycin can result in uneven drug distribution and high mortality rates. The refined unilateral intratracheal instillation method for bleomycin administration in mice enables the creation of a more uniform and controlled pulmonary fibrosis model, providing a better simulation of the disease in humans. Here we present a protocol to utilize micro-computed tomography (micro-CT) to quantify ventilated regions in a unilateral bleomycin-induced pulmonary fibrosis model via intratracheal instillation on the lesional side. This approach allows for the quantification of overall lung volume and ventilated lung regions, providing a sensitive and accurate measure of disease progression and treatment response. This study involves anesthesia, precise drug administration, micro-CT scanning, and post-processing using 3D Slicer software for image analysis. The unilateral lung volume analysis following bleomycin treatment demonstrated a significant reduction in lung volume compared to controls. Masson's Trichrome staining confirmed the presence and increased deposition of collagen in the BLM-treated mice. Herein, we evaluated pulmonary fibrosis in preclinical models by performing unilateral lung volumetric analysis using micro-CT, providing researchers with a precise and thorough assessment method for evaluating therapeutic interventions in PF studies.