Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Heart size is normal . Mediastinal and hilar contours are unremarkable . The pulmonary vasculature is normal . There is minimal patchy opacity in the left lung base . This likely reflects atelectasis . No focal consolidation , pleural effusion or pneumothorax is identified . There are no acute osseous abnormalities .
    OUTPUT:
    
Patchy opacification of the left lung base likely reflects atelectasis though infection is not excluded in the correct clinical setting .