Diaphragm Structure and Pathobiology in Patients Being Bridged to Lung Transplant

Inclusion Criteria (Cases): * Receiving a respiratory support modality as a bridge to lung transplantation * Formally listed for transplantation Inclusion Criteria (Control Group 1): \- Undergoing lung transplantation for either obstructive or restrictive lung disease Inclusion Criteria (Control Group 2): \- Undergoing elective thoracic surgery without any prior history of chronic pulmonary parenchymal disease Exclusion Criteria (Cases and Controls): * Previously diagnosed with neuromuscular disorder * Received invasive mechanical ventilation for \>48 hours in the preceding four weeks * Thoracic cage deformity