Radioaerosol mucociliary clearance of tracheobronchial tree in normal subjects and in patients with respiratory diseases.

The rate of mucociliary clearance in the tracheobronchial tree was studied both in patients and controls using radioisotopic techniques. The radioisotope is deposited in the larger airways and its rate of movement is measured as it is being transported up the trachea due to mucociliary activity. The BARC aerosol generation system was modified and used for this purpose. One hour study was acquired on a computerised gamma camera in each case. The rate of movement of the bolus of radioactivity was calculated by measuring the distance travelled in a known period of time. The mean velocity of transport was 9.0mm/min in normal subjects. In patients variable speed of transportation was obtained ranging from absolutely no movement to near normal speeds. Different patterns of transport were observed including linear, spiral, static and regurgitative. It was concluded that this simple non-invasive technique can be used for in vivo monitoring of mucociliary tracheal activity.