Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A pleural line is vaguely apparent in the interspace between the third and fourth posterior ribs , although very difficult to visualize . No focal consolidation , pleural effusion , or left pneumothorax . Cardiomediastinal and hilar contours unchanged .
    OUTPUT:
    
No substantial change in the right apical pneumothorax , however the pleural line it is extremely difficult to visualize on the current radiograph .