Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The lungs are well expanded and clear . There is no pleural effusion or pneumothorax . The cardiomediastinal silhouette is unremarkable . Central pulmonary arteries appear prominent in caliber , however .
    OUTPUT:
    
No evidence of acute cardiopulmonary process . Prominent central pulmonary arteries , significance uncertain although etiologies such as pulmonary hypertension are possible .