Inclusion Criteria:  Males or females age 8 - 20 years of age at enrollment Subjects with history of lung transplant Available clinically indicated pulmonary function test  Exclusion Criteria:  Any contraindication to the safe performance of MRI (metallic foreign bodies, non-safety rated implanted devices including but not limited to vascular clips, pacemaker, stent, infusion pump, neuro-stimulator, prosthesis) Subject unable to perform a spirometry Individuals requiring conscious sedation or anesthesia Severe claustrophobia Pregnant females