Airway Clearance Therapy on Hyperpolarized 129Xenon and MRI

This is an observational cohort study building on an existing protocol at our institution recruiting CF patients who are 6-21 years old with one or two copies of the F508del CFTR mutation. That existing protocol seeks to enroll a total of 38 subjects; it includes three to four (three scheduled, with a fourth optional) study visits, with spirometry, LCI, UTE MRI, and 129Xe MRI being performed at each visit. This present study will utilize existing study visits for the NHLBI study, with a sub-set of 20 subjects opting-in to have all of the procedures performed twice, with an intervening ACT, during one of their study visits.