Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac silhouette is stably enlarged . The lungs are clear . There is no pleural effusion or pneumothorax . A Swan - Ganz catheter is again noted , with the tip extending past the right main pulmonary artery , likely into a right lobar pulmonary artery .
    OUTPUT:
    
Swan - Ganz catheter positioned distal to the right main pulmonary artery .