Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiomediastinal silhouette and hilar contours are unremarkable . The left hemidiaphragm is elevated , unchanged . Linear atelectasis at the left lung base is also unchanged . No evidence of focal opacity in the lungs concerning for an infectious process . No pneumothorax or pleural effusion . Stable compression of T12 .
    OUTPUT:
    
No evidence of pneumonia .