Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiographs are provided . There is no pleural effusion or pneumothorax . Subtle ill - defined opacity is present in the left lower lobe maybe atelectasis but can not exclude infection . Cardiomediastinal silhouette is normal . Osseous structures are unremarkable .
    OUTPUT:
    
Ill - defined left lower lobe opacity may represent atelectasis but can not exclude infectious process .