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 obtained four hours earlier during the same day . The position of the ETT is unchanged and symmetrical within the lumen of the trachea . The tube terminates just above the previously described left - sided impression on the trachea caused by the now operated aneurysm . Postoperative widening of the superior mediastinum is unchanged during the latest four hours . The Swan - Ganz catheter has been withdrawn but the right internal jugular sheath remains in position . There is now a small right - sided apical pneumothorax measuring up to 2 cm in width . When reviewing the same area on the preceding examination four hours ago , such pneumothorax was not present . On the other hand , evidence of bilateral air inclusion in Bibasilar hazy densities and obliteration of the diaphragmatic the pectoralis muscle structures is again noted as before . contours is suggestive of bilateral pleural effusion . The latter finding appears to be stable .
    OUTPUT:
    
Development of small right apical pneumothorax possibly related to Swan - Ganz removal and the remaining sheath . ___ was informed by telephone .