19F MRI to Evaluate Regional Ventilation in Healthy Subjects and Subjects With Cystic Fibrosis

The goal of this study is to evaluate the ability of conventional 'thermally' polarized perfluorinated gases (19F) mixed with oxygen to detect changes in ventilation using magnetic resonance imaging (MRI). A secondary goal is to assess the repeatability and the within-subject variability of these findings in CF lung disease. This is an open label pilot study expanding on work by other investigators currently using this technique in human subjects. Projection images using controlled breathing techniques will be obtained using 19F MRI, correlating spirometric variables with regional distribution of the gases.