Diagnostic Aerosols: Current Status and Future Prospects

Abstract

The inhalation of diagnostic aerosols directly into the respiratory tract (RT) can mimic the entry of air, inhaled allergens, and toxins. Such inhalation has also the advantage for diagnosis of diseases of the RT in that the active ingredient has, at least initially, a high ratio of local/systemic concentration. Nonradioactive aerosols have been used in the bronchial reactivity testing and as contrast media in bronchography. More recent developments include the assessment of airway dimensions and presence of airway diseases by means of the aerosol bolus technique. Radiolabeled aerosols have been used for anatomical (static) imaging of RT and in the kinetic mode to follow the clearance processes. Gamma scintigraphy has been used extensively in the differential diagnosis of pulmonary embolism and ventilation defects. Detection and localization of airway obstruction are also possible using radioaerosols. Transport processes in the RT can be followed by delivering radiolabeled soluble probes by inhalation to ...