Cystic Fibrosis (CF) Group: must have a diagnosis of CF
No use of supplemental oxygen
They must be able to perform spirometry and have stable lung function (within 10% personal best in the last 6 months) and no exacerbations within the past 4 weeks
Baseline forced expiratory volume in 1 second (FEV1) \>80% with ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lung (FEV1:FVC) ratio \>0.7
You may not be if
Healthy volunteers: with any history of chronic lung disease (i.e. asthma)
Active or former smoker with less than 1 year of quitting
Unable to undergo an MRI of the lungs and chest because of contraindications, including:
* Injury to the eye involving a metallic object
* Injury to the body involving a metallic object
* Presence of an implanted drug infusion device that is not MRI safe
* Bone growth of fusion simulator
* Presence of cochlear, otologic, or ear implant
* Shunt (spinal or intraventricular)
* Any implant held in place by magnet
* Claustrophobia
Unable to tolerate the inhalation of the gas mixture
Facial hair preventing a tight fit of the mask used in the study
Pregnancy
Changes in medication that may affect CF lung disease or lung function in the past 28 days, including experimental therapies
