Computer assisted measurement of airway gland secretions by the hillocks technique

We describe a computer-based image acquisition and analysis system designed for the quantitation of airway submucosal gland fluid flux by the hillocks technique. This technique is based on the detection of the increase in surface area of hillocks formed above gland duct openings by secretions captured under a thin layer of tantalum powder. The advantages of the system are: (a) ability to detect and measure individual submucosal gland secretions, (b) computer assisted data acquisition and analysis, and (c) decreased propagated error in hillock volume measurements. Test results of a practical implementation of the system demonstrate a swine tracheal submucosal gland flux induced by the muscarinic agonist acetylcholine (50 microM) of 0.65 microl/min/cm(2).