Healthy volunteers aged 18 to 85 will undergo hyperpolarized Xenon-129 (¹²⁹Xe) MRI and pulmonary function testing. The study aims to develop evaluation tools for ventilation defect percent (VDP), signal-to-noise and contrast-to-noise ratios (SNR/CNR) of ¹²⁹Xe dissolved-phase images, and spectroscopy-based analysis.

Briefly, during a one hour visit, subjects will provide written informed consent and then undergo:

1. brief medical history and vital signs,
2. full pulmonary function tests,
3. proton MRI,
4. spin-density, diffusion weighted, and/or dissolved phase 129-Xe MRI, Full pulmonary function tests including spirometry and FeNO test according to American Thoracic Society (ATS) guidelines.

Subjects will be placed in the 3T Magnetic Resonance (MR) scanner with one 129-Xe chest coil fitted over their torso and chest. Hearing protection will be provided to each subject to muffle the noise produced by the gradient radiofrequency (RF) coils. A pulse oximeter lead will be attached to all of the subjects to monitor their heart rate and oxygen saturation. MRI will be performed for up to a period of 30 minutes. All subjects will have supplemental oxygen available via nasal cannula at a flow-rate of 2 liters per minute as a precaution in the event of oxygen desaturation.

Inclusion Criteria:

• Patient understands study procedures and is willing to participate in the study as indicated by the patient's signature.
• Provision of written, informed consent prior to any study specific procedures.
• Males and females aged 18 to 85 years.
• Participant must be able to perform a breath-hold for 16s.
• Participant has a BMI between 18 and 40
• Participant must be able to perform reproducible pulmonary function tests (i.e., the 3 best acceptable spirograms have forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) values that do not vary more than 5% of the largest value or more than 100 ml, whichever is greater)
• Participants are judged to be in stable health on the basis of medical history

Exclusion Criteria:

• Patient has an MR incompatible implanted mechanically, electrically, or magnetically activated device or any metal in their body which cannot be removed, including but not limited to pacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment or foreign body, shunt, surgical staples (including clips or metallic sutures and/or ear implants) (at the discretion of the MRI Technologist).
• In the investigator's opinion, subject suffers from any physical, psychological or other condition(s) that might prevent performance of the MRI or CT, such as severe claustrophobia.
• Participants who are pregnant, breastfeeding or have a positive pregnancy test at initial screening visit.
• Participant is unable to perform spirometry maneuvers.
• Participant is unable to perform MRI and CT breath-hold maneuvers.
• Participant has a history of chronic or acute respiratory disease
• FEV1 <70%
• Participant has a history of cardiovascular disorders including coronary insufficiency, cardiac arrhythmias, severe hypertension (≥160 over ≥100)
• Participant has a daytime room air oxygen saturation ≤ 92% ± 2% while supine

Deidentified individual participant data supporting the results will be shared beginning 9 months after publication, available for up to 5 years. Access is open to researchers with approved proposals, subject to a data use agreement. Data will be shared via a secure platform upon approval