This study is being done to study a safe and non-invasive way to diagnose lung rejection and infection.

Lung transplant recipients are at high risk for lung rejection and lung infection after transplant. This is diagnosed by performing lung bronchoscopies and lung biopsies. These procedures carry an increased risk for complications and are costly. This study is being done to study a safe and non-invasive way to diagnose lung rejection and infection.

Inclusion Criteria:

• Adult patients (> 18 yrs) who had undergone single/double/heart-lung transplant
• Asymptomatic
• Normal spirometry defined as a FEV1 without significant drop from baseline (significant drop = >10% decrease from baseline)
• Clear chest radiograph over allograft

Exclusion Criteria:

• Patients who are unable to consent for the procedure
• Patients with subcutaneous emphysema or other technical challenges that could interfere with satisfactory image acquisition- as deemed by the operator.

This study is not blinded