Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate normal cardiomediastinal silhouette . The lungs are clear . There is no pneumothorax , vascular congestion , or pleural effusion . Ill - defined slight increase in density in the left base is felt to represent low lung volumes with overlapping vascular structures , less likely consolidation , to be clinically correlated .
    OUTPUT:
    
No definite evidence of pneumonia .