Consolidation vs Collapse on Chest X-ray

A 58-year-old woman with lung cancer undergoes right upper lobe resection. Post-operative day 3 chest X-ray shows opacity in the right hemithorax with the right heart border remaining visible and the right hemidiaphragm in normal position. Which investigation is most appropriate to determine whether this represents post-operative consolidation or atelectasis?

A 62-year-old man with a history of COPD and smoking presents with acute dyspnea and hypoxemia. Chest X-ray shows a wedge-shaped opacity in the right lower lobe with ipsilateral mediastinal shift, loss of lung volume, and absence of air bronchograms. All of the following radiological signs support the diagnosis of atelectasis EXCEPT:

Regarding the radiological distinction between pulmonary consolidation and atelectasis (collapse) on chest X-ray, all of the following statements are correct EXCEPT:

A 72-year-old man with lung cancer presents with progressive dyspnea over 3 days. Chest X-ray shows opacification of the entire right hemithorax with rightward tracheal deviation and elevation of the right hemidiaphragm. The left lung is hyperinflated. What is the most appropriate next step in management?

A 62-year-old man with COPD presents with acute dyspnea and cough. Chest X-ray shows an area of increased opacity in the right lower lobe with air bronchograms and preserved volume. What is the most common cause of this radiological finding?