Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP single view of the chest has been obtained with patient in semi-upright position . Analysis is performed in direct comparison with the next preceding similar study dated ___ . During the one - day interval , the previously existing right - sided chest tube has been removed . There is now a small apical pleural separation of less than 0 .5 cm in width . Otherwise , the lungs appear well aerated and the previously present plate atelectasis on the right lung base remains unchanged . Similar as on previous examination , there exists a hazy density in the left upper lobe area , probably a pneumonic infiltrate . Heart size and mediastinal structures remain unchanged and the same holds for the double - lumen catheter introduced via the right internal jugular approach and terminating in the mid portion of the SVC .
    OUTPUT:
    
Very small apical pneumothorax , but otherwise unchanged chest findings .