Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is chronic elevation of left hemidiaphragm . The lungs are well expanded and clear . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable .
    OUTPUT:
    
No acute cardiopulmonary process . Chronic elevation left hemidiaphragm could be due to previous trauma , eventration , or phrenic nerve palsy .