Imaging Airway Liquid Absorption in Cystic Fibrosis

The investigators have recently developed a novel aerosol-based imaging technique to detect changes in liquid absorption in the airways - a central pathophysiological process known to be important in cystic fibrosis (CF) lung disease. This technique may provide a measure of disease severity and indication of therapeutic correction in advance of currently available outcome measures. It involves the simultaneous delivery of two radiopharmaceuticals by inhalation: one an absorbable small-molecule (Indium-111 labeled diethylenetriaminepentaacetic acid; In-DTPA) and the other a non-absorbable particle (Technetium 99m labeled sulfur colloid; Tc-SC). The overarching hypothesis is that In-DTPA absorption provides a quantifiable, non-invasive measurement of airway liquid absorption that (a) is sensitive to CF genotype, (b) uniquely identifies basic disease phenotype and predicts disease severity, and (c) is modulated by therapeutic interventions.