Chronic Lung Allograft Dysfunction MRI Study

All subjects-Inclusion Criteria:

* Ages 18-80
* English Speaking Subjects
* Willingness and ability to provide informed consent
* Non-smoker

Lung transplant patients-inclusion criteria:

* \>/= 6 months from lung transplant
* History of bilateral lung transplant

CLAD-free patients-inclusion criteria:

* Stable spirometry with FEV1 \> 90% of baseline value (average of 2 best values) and forced mid-expiratory flow (FEF) (25-75) \> 75% of baseline
* Total Lung Capacity (TLC) \> 90 % of baseline
* Post-transplant chest radiograph without significant abnormality
* No evidence of on-going lung infection or allograft rejection

Early CLAD patients-inclusion criteria:

* FEV1 \< 80% of baseline value (average of 2 best values)
* Follow up 6-months or decline in lung function (20% decrease in FEV1 without evidence of infection or acute rejection)

Exclusion Criteria:

* SAO2 drops below 90% (in absence of mechanical failure) during normal tidal breathing
* Unilateral diaphragm paralysis
* Evidence of acute illness on day of study
* Evidence of restrictive lung disease
* Dependence on supplemental oxygen
* History of cardiac disease
* Pregnancy (self-declared)
* Lactating women
* Participants with metal objects in their body
* Known contraindication to MRI examination
* Systolic blood pressure reading of \< 100 mmHg or \> 200 mmHg
* Diastolic blood pressure reading of \<60 mmHg or \> 100 mmHg