Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A Swan - Ganz catheter was pulled back approximately 4 cm since the prior study and the tip terminates in the right main pulmonary artery . There is mild pulmonary edema . The heart is moderately enlarged . There is no pneumothorax or pleural effusion . Otherwise , no significant changes compared to prior study .
    OUTPUT:
    
Swan - Ganz catheter tip pulled back approximately 4 cm . No pneumothorax .