LAUSR

The current standard for lung function evaluation in murine models is based on forced oscillation technology, which provides a measure of the total airway function, but cannot provide information on regional heterogeneity in function. Limited detection of regional airflow may contribute to a discontinuity between airway inflammation and airflow obstruction in models of asthma. Here, we describe quantification of regional airway function using novel dynamic quantitative imaging and analysis to quantify and visualize lung motion and regional pulmonary airflow in 4dimensions (4D). Furthermore, temporospatial specific ventilation (SV; ml/ml) is used to determine ventilation heterogeneity (VH) indices for lobar and sub-lobar regions, and are directly compared to ex-vivo biological analyses in the same sub-lobal regions. In contrast, oscillation-based technology in murine genetic models of asthma have failed to demonstrate lung function change despite altered inflammation, whereas 4D functional lung imaging demonstrated diminished regional lung function in genetic models relative to wild type mice. Quantitative functional lung imaging assists in localizing the regional effects of airflow. Our approach reveals repeatable and consistent differences in regional airflow between lung lobes in all models of asthma, suggesting that asthma is characterized by regional airway dysfunctions that are often not detectable in composite measure of lung function. 4D functional lung imaging technology has the potential to transform discovery and development in murine models by mapping out regional areas heterogeneously affected by the disease, thus deciphering pathobiology with greater precision.