Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Subtle left basilar opacity may represent atelectasis however early infectious process is not excluded in the appropriate clinical setting . The right lung is clear . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
Subtle left basilar opacity may represent atelectasis however early infectious process is not excluded in the appropriate clinical setting .