Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There is a small pneumothorax at the left apex . It measures 9 mm at its widest margin . The lungs are well expanded . The heart appears normal in size and configuration . Cardiomediastinal contours are unremarkable . The lungs are clear with no evidence of focal infiltrates . No pleural effusions . Bony structures are intact .
    OUTPUT:
    
Small , 9 - mm , pneumothorax is seen at the left apex .