Airway remodeling in a mouse asthma model assessed by in-vivo respiratory-gated micro-computed tomography

The aim of our study was to evaluate the feasibility of non-invasive respiratory-gated micro-computed tomography (micro-CT) for assessment of airway remodelling in a mouse asthma model. Six female BALB/c mice were challenged intranasally with ovalbumin. A control group of six mice received saline inhalation. All mice underwent plethysmographic study and micro-CT. For each mouse, peribronchial attenuation values of 12 bronchi were measured, from which a peribronchial density index (PBDI) was computed. Mice were then sacrificed and lungs examined histologically. Final analysis involved 10 out of 12 mice. Agreement of measurements across observers and over time was very good (intraclass correlation coefficients: 0.94-0.98). There was a significant difference in PBDI between asthmatic and control mice (-210 vs. -338.9 HU, P = 0.008). PBDI values were correlated to bronchial muscle area (r = 0.72, P = 0.018). This study shows that respiratory-gated micro-CT may allow non-invasive monitoring of bronchial remodelling in asthmatic mice and evaluation of innovative treatment effects.