Measurement of non-uniform aerosol deposition patterns in the conducting airways of the porcine lung

A technique is described for high-resolution measurement of aerosol deposition patterns in the conducting airways: using a fluorescently labelled aerosol in an isolated lung preparation. Results are presented for the deposition of a micron-sized aerosol in the porcine lung. The deposition distributions in the neighbourhood of a number of large bronchial bifurcations are reconstructed from serial sections. The deposition pattern is found to be extremely inhomogeneous, with the highest concentrations typically occurring in localised "hot spots" near the carinal ridge. There is also a great deal of variability in deposition between different bifurcations. The relationship with previous experimental and theoretical work and some possible physiological implications are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.