Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Analysis is performed in direct comparison with the next preceding PA and lateral chest examination of ___ . Heart size , mediastinal structures , and pulmonary vasculature are within normal limits and unchanged . Again noted is the mild degree of left lateral pleural blunting extending mildly into the posterior pleural sinus . When comparison is made with the preceding study , the amount of pleural effusion remains small and is practically unchanged . No pneumothorax has developed , and no new infiltrates are seen .
    OUTPUT:
    
Stable chest findings . No evidence of recurrent pleural effusion . The small amount of low density is similar to what has been seen post thoracocentesis performed on ___ .