Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are clear . There is no pneumothorax . The heart size appears smaller on today 's exam , and is now within normal limits . Mediastinal contours are stable . Left lateral chest wall postsurgical changes are also stable . Mild spinal degenerative changes are unchanged .
    OUTPUT:
    
Clear lungs with no evidence of pneumonia or pulmonary edema .