Deposition patterns on aerosol inhalation lung images and chronic obstructive pulmonary diseases

Five radioaerosol deposition patterns were described based on the quantitative analysis of unevenness on radioaerosol inhalation lung images and lung function data. Central, peripheral and their mixed deposition patterns were seen in chronic obstructive pulmonary diseases. Differences in each deposition pattern was characterized by our numerical analysis of unevenness on images. In minimal uneven aerosol deposition patterns, obstructive changes in lung function data were also minimal. The more marked central and/or peripheral deposition patterns, the more marked disturbances in lung function data: i.e., the more marked decrease in FEV1.0% and increase in RV/TLC. The difference between the peripheral and the central aerosol deposition patterns was the presence of hilar deposition of inhaled aerosol whereas hot spots in the peripheral lung regions were similar in both the central and peripheral deposition patterns. (author)