Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is equivocal subtle opacity in the left lung base , which may represent atelectasis or , possibly , an early , developing pneumonia . No other areas of focal consolidation , pleural effusion or pneumothorax . Cardiomediastinal silhouette is within normal limits . No acute osseous abnormalities identified .
    OUTPUT:
    
Equivocal subtle opacity at the left lung base , which may represent atelectasis or developing pneumonia . Otherwise , chest x-ray examination is within normal limits .