Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is persistent elevation of the right hemidiaphragm and overall low lung volumes . Prominence of the pulmonary vasculature again suggests mild interstitial pulmonary edema . The cardiac and mediastinal silhouettes are stable . No pleural effusion or pneumothorax is seen . The patient is status post median sternotomy , similar in appearance . Degenerative changes are seen along the spine .
    OUTPUT:
    
Persistent mild interstitial pulmonary edema . Persistent elevation of the right hemidiaphragm .