Fig. 1
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40413-017-0153-4/MediaObjects/40413_2017_153_Fig1_HTML.gif)
Lung Deposition of Beclomethasone diproprionate, Hydrofluoroalkane vs chlorofluorocarbon propellant inhaler [81]. Note the mosaic pattern of areas of low attenuation (representing air – which appears black – trapped behind diseased and functionally closed small airways) juxtaposed with areas of higher attenuation (whiter-appearing, representing lung regions from which the air has been normally expelled through patent airways)