Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The patient is status post median sternotomy , CABG , mitral valve surgery , and right upper lobectomy . Volume loss in the right lung is again noted with scarring again seen in the right lung base . Ill - defined opacity projecting over the right hilum appears similar to the prior study , likely reflecting a combination of postoperative changes from prior upper lobe resection and residua of the previously seen air and fluid collection in the retrosternal space . Though , no air is identified within the retrosternal space on the current lateral view . The cardiac and mediastinal contours are stable . No new focal consolidation , pleural effusion or pneumothorax is present . There are no acute osseous abnormalities .
    OUTPUT:
    
No significant interval change from the prior study except that the previously noted gas seen within a retrosternal fluid collection appears to have resolved .