Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Compared to the chest radiograph obtained 4 hours prior , a moderate right pneumothorax is increased in size . Apparent leftward mediastinal shift is less conspicuous , however . Right lower lobe atelectasis is more prominent . No pleural effusion . Heart size is normal . Cardiomediastinal hilar silhouettes are unremarkable .
    OUTPUT:
    
Increased , moderate right pneumothorax with less conspicuous leftward mediastinal shift , still raising the possibility of tension .