Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral views of the chest are obtained . The previously seen left mid lung bleb and right mid lung bulla are again demonstrated , however there is interval resolution of the previously seen air - fluid level within the left mid lung bulla . Evidence of prior left apical bullectomy is again seen with persistence of moderate left pneumothorax . There is no focal consolidation or significant pleural effusion . The heart is normal in size .
    OUTPUT:
    
Interval resolution of air - fluid level in the left mid lung bulla and persistence of moderate left pneumothorax status post left apical bullectomy . Otherwise , unchanged since the prior study .