Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Tracheostomy tube is seen coursing into the midline , overlying the trachea . The patient is status post median sternotomy and CABG . There has been a center resolution of previously seen perihilar opacities . There are bibasilar opacities which could be due to aspiration , infection , and / or atelectasis . No large pleural effusion is seen . There is no evidence of pneumothorax . The cardiac and mediastinal silhouettes are grossly stable . There are extensive vascular calcifications .
    OUTPUT:
    
Interval essential resolution of previously seen perihilar opacities . Patchy bibasilar opacities may be due to infection , aspiration , and / or atelectasis .