Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest demonstrate normal cardiomediastinal silhouette . There is trace increased focal opacity in the left base without correlation on lateral view , likely representing summation of shadows from vascular structures . The lungs are otherwise clear . There is no pneumothorax , vascular congestion , or pleural effusion .
    OUTPUT:
    
No acute cardiopulmonary process .