Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in sitting semi-upright position . Analysis is performed in direct comparison with the next preceding similar study of ___ . The previously described left - sided pigtail end drainage catheter remains in unchanged position . The previously remaining significant pleural effusion has now been drained almost completely . The left - sided diaphragmatic contour can again be identified . There are some linear densities in the left lower lung base suggestive of atelectasis . The right - sided hemithorax remains unchanged and is normal .
    OUTPUT:
    
Effective removal of left - sided pleural effusion , no evidence of pneumothorax .