Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP and lateral views of the chest . Tracheostomy tube is seen in place . Mild cardiomegaly is unchanged . There are bibasilar opacities that may represent atelectasis ; however , aspiration or pneumonia can not be ruled out . Correlate clinically . No large pleural effusion or pneumothorax .
    OUTPUT:
    
Mild interstitial edema . Bibasilar opacities are likely chronic . CT can be done to assess for subtle changes .