¹⁹F (Perfluoropropane) MRI

Briefly, during this two-hour visit, participants will provide written informed consent and then undergo: 1. Brief medical history and vital signs, 2. Full pulmonary function tests, 3. Proton MRI, 4. 19F(perfluoropropane) MRI, As part of the MRI, participants will inhale or 19F gas as a contrast agent to assess lung ventilation Spirometry will be performed at each visit according to American Thoracic Society (ATS) guidelines using MedGraphics Elite Series (MedGraphics Corporation. St. Paul, MN USA) and/or nDD EasyOne Spirometer (nDD Medical Technologies Inc. Andover, MA USA). Fractional exhaled nitric oxide (FeNO) will be measured using the NIOX VERO® (Circassia Pharmaceuticals Inc., Morrisville, NC, USA). All measurements will be performed at St Joseph's Healthcare London. They will be placed in the 3T PET/MRI scanner with a coil fitted over their torso and chest. Hearing protection will be provided to muffle the noise produced by the 3D imaging gradient coils. A pulse oximeter lead will be used to monitor heart rate and oxygen saturation. MRI will be performed for up to a period of seven to ten minutes. All imaging will be performed in a "breath-hold" fashion. All participants will have supplemental oxygen provided via nasal cannula at a flow rate of at least two liters per minute during the scanning process. Logs and records of gas exposure will be maintained for every volunteer in this study.