Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy left base opacity seen , which could be due to pneumonia and / or atelectasis . The right lung is clear . No large pleural effusion or pneumothorax is seen . Cardiac mediastinal silhouettes are stable . Surgical clips in noted overlying the left hemithorax .
    OUTPUT:
    
Patchy left base opacity new since the prior study could be due to pneumonia or atelectasis . Dedicated PA and lateral views would be helpful for further assessment if patient able .