Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: An endotracheal tube , NG tube , and right upper extremity PICC with its tip at the cavoatrial junction are unchanged . There is no change in left lower lobe opacity . There is no large pleural effusion , or pneumothorax . The cardiac silhouette remains moderately enlarged , mediastinal contours are notable for calcification of the aortic arch .
    OUTPUT:
    
Mild residual retrocardiac opacification remains , pneumonia vs . atelectasis .