Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Mild bibasilar opacities are likely atelectasis . No pneumothorax or pleural effusion is identified . Cardiomediastinal and hilar silhouette are normal size . Curvilinear dense opacity in the retrosternal region is unchanged and may reflect focal calcified pleural plaques or pericardium .
    OUTPUT:
    
Mild bibasilar opacities are likely atelectasis .