Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is stably enlarged . Right hilar enlargement is compatible with right pulmonary artery enlargement suggesting pulmonary hypertension . The central pulmonary vasculature is prominent , also unchanged since prior examination . The lungs are clear . There is no definite pleural effusion or pneumothorax .
    OUTPUT:
    
No acute intrathoracic process .