Bleomycin-induced lung disease in an animal model: Correlation between computed tomography determined abnormalities and lung function

Rationale and Objectives. The authors evaluated whether specific types of computed tomographic (CT) abnormalities could be correlated with physiologic impairment in animals with bleomycin-induced lung injury. Methods. Lung injury was induced in 20 rabbits by means of intratracheal administration of bleomycin (3 U per kilogram of body weight), followed by 100% oxygen for 2 minutes. The animals underwent high-resolution CT scanning at 14 (n = 4), 28 (n = 6), or 56 (n = 10) days after injury. CT morphometry was used to determine the extent of abnormal lung. Physiologic evaluation was performed before injury and before scanning. Results. The overall extent of abnormal lung and of parenchymal opacification on CT scans did not correlate with any physiologic variable. The extent of interstitial thickening correlated significantly with total lung capacity (r = -.783, P = .0005), airway pressure at maximal lung volume (r = .836, P = .0001), and alveolar-arterial oxygen gradient (r = .613, P = .004). Conclusion. CT findings of interstitial thickening are associated with impaired gas exchange and lung stiffness in rabbits.