Aerosol-Derived Airway Dimensions of Dog Lungs: Comparison of Bolus and Single-Breath Techniques

Abstract

Changes in the diameter and cross-section of pulmonary airways and alveoli constitute an important factor associated with many diseases of the lung (Thurlbeck 1985). Diagnostic techniques for the assessment of airway dimensions are restricted to larger airways (visualization by bronchoscopy or radiographic techniques; Fraser and Pare 1977; Sackner 1980), to indirect functional techniques (determination of airway resistance or closing volume; Metzger et al. 1980), or for detecting changes in the late stage of the disease when lung function is severely impaired. Analysis of the behavior of inhaled 1-pm monodisperse aerosol particles presents a novel noninvasive technique for functional morphometric assessment of airway dimensions in vivo. Two different techniques may be used: (a) inhalation of a bolus of monodisperse particles at varying points of the inspired volume (Bolus technique; Palmes et al. 1973; Heyder 1983) and (b) inhalation of a single breath with test particles contained in the inspired tidal volume (single-breath technique; Heyder 1989).