Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since ___ , known left pneumothorax is unchanged and measures 1 .7 cm from the left lung apex . Unchanged appearance of known pulmonary fibrosis and low lung volumes . Left chest tube placement is unchanged . No evidence of tension . Heart size is normal .
    OUTPUT:
    
Unchanged known left pneumothorax measure 1 .7 cm on the left lung apex since ___ .