Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since the radiographs obtained 4 days prior , no significant changes are appreciated . Lung volumes remain low and mild elevation of the left hemidiaphragm with mild left lower lobe atelectasis are unchanged . The lungs are clear without focal consolidation . Cardiomediastinal and hilar silhouettes are normal . Pleural surfaces are normal .
    OUTPUT:
    
No radiographic evidence of pneumonia or acute cardiopulmonary abnormality .