Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patchy left base opacity may be due to atelectasis although underlying infection to be present in the appropriate clinical setting . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Patchy left base opacity may represent combination of atelectasis and left lower lobe pneumonia .