Chronic allograft rejection of the transplanted lung (CLAD) is a major health issue in patients after lung transplant. This study is a registry-forming study with concurrent tissue banking from surveillance bronchoscopy in addition to extra tissue sampling of blood and urine. Patients will be characterized by usual clinical phenotyping and the latest imaging methods so that diseased condition underlying CLAD can be better understood.

Chronic allograft rejection of the transplanted lung (CLAD) is a major health issue that lead to almost 50% mortality within 5 years from the time of lung transplant. In the past CLAD was exclusively occurring in small airways causing a condition called "Bronchiolitis Obliteran Syndrome" (BOS). However, recently many have observed restrictive changes in lung physiology with or without parenchymal abnormalities. This new CLAD is called RAS or RCLAD. What is also concerning is that RAS is thought to be associated with disproportionally high morbidity and mortality. This clinical trial intends to create a registry of patients who completed lung transplant and who are undergoing routine surveillance bronchoscopy. A subgroup of patients will be characterized by hyper polarized gas magnetic resonance image to enhance detection of CLAD, and to be correlated between the MRI imaging results and clinical/biochemical results. This study is anticipated to advance our understanding of CLAD which is currently inevitably fatal outcome among patients after lung transplant.

Inclusion Criteria:

1. All patients who successfully underwent lung transplant at the University of Virginia.
2. Followed by medical lung transplant team for post-lung transplant rejection surveillance program at the University of Virginia.
3. Subjects with co -morbid illnesses such as neurologic, liver and or kidney or GI tract disease/ dysfunction are not excluded
4. Clinically stable to undergo MRI Imaging

Exclusion Criteria:

1. Continuous oxygen use at home if decided to consent for MRI imaging
2. Blood oxygen saturation of less than 92%as measured by pulse oximetry on the day of imaging if decided to consent for MRI imaging.
3. Forced Expiratory Volume in 1 second (FEV1) percent predicted less than 25% if decided to consent for MRI imaging.
4. Pregnancy or lactation if decided to consent for MRI imaging.
5. Claustrophobia, inner ear implants, aneurysm or other surgical clips, metal foreign bodies in eye, pacemaker or other contraindication to MR scanning. Subjects with any implanted device that cannot be verified as MRI compliant will be excluded if decided to consent for MRI imaging.
6. Chest circumference greater than that of the xenon MR and/or helium coil. The circumference of the coil is approximately 42 inches if decided to consent for MRI imaging.
7. History of congenital cardiac disease, chronic renal failure, or cirrhosis if decided to consent for MRI imaging.
8. Inability to understand simple instructions or to hold still for approximately 10 seconds if decided to consent for MRI imaging.
9. History of respiratory infection within 2 weeks prior to the MR scan if decided to consent for MRI imaging.
10. History of MI, stroke and/or poorly controlled hypertension if decided to consent for MRI imaging.