Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Again noted is the small post-operative pneumopericardium , which is stable in appearance compared to the last chest radiograph . Median sternotomy wires are in the expected location . Again noted is the left sided chest tube , Swan Ganz catheter , mediastinal drains , endotracheal tube , and a nasogastric tube . There is better ventilation of the left lung compared to the last chest radiograph performed on ___ at 15 : 18 . No large pleural effusions are noted . No evidence of pneumothorax .
    OUTPUT:
    
1 . Improved ventilation of the left lung when compared to the last CXR taken ___ at 3 : 19 PM . 2 . Stable post-operative pneumopericardium .