Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are unchanged . Heart size is within normal limits . The pulmonary vascularity is not engorged . Blunting of the costophrenic angles bilaterally is compatible with small bilateral pleural effusions , relatively unchanged . Streaky opacities at lung bases likely reflect atelectasis . No pneumothorax is identified . There are mild degenerative changes in the thoracic spine .
    OUTPUT:
    
Streaky opacities within the lung bases likely reflect bibasilar atelectasis . Small bilateral effusions , relatively unchanged .