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 . Comparison is made with the next preceding similar study obtained 12 hours earlier during the same day . Previously described two right - sided chest tubes remain in unchanged position . Apical pneumothorax persists and appears to be unchanged . No new pulmonary abnormalities identified and the left hemithorax is unremarkable .
    OUTPUT:
    
Stable appearance of moderately sized right - sided apical pneumothorax .