Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low leading to crowding of the bronchovascular structures . The lungs are otherwise clear without focal consolidation , pleural effusion , pneumothorax , or pulmonary edema . The patient is status post midline sternotomy with multiple sternotomy wires midline and intact . The heart is normal in size .
    OUTPUT:
    
Low lung volumes without acute cardiopulmonary process .