Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . Dilated main pulmonary artery and proximal branches are unchanged since at least ___ as assessed by CT . The hila are normal . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
No evidence of acute cardiopulmonary process . Chronic pulmonary artery dilatation .