Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest was obtained with patient in sitting semi-upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . During the interval , right - sided thoracocentesis was performed . The massive right - sided pleural density as identified on the previous examination has decreased moderately . Still the remaining pleural effusion obliterates totally the right - sided hemidiaphragm and reaches along the right - sided lateral chest wall . After the thoracocentesis , there is no evidence of any hydropneumothorax in the right hemithorax . Left - sided pulmonary changes which include a plate atelectasis in the left lung base remain unchanged . No new abnormalities are seen .
    OUTPUT:
    
Marked reduction of right - sided pleural effusion after thoracocentesis , no pneumothorax .