Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single AP view of the chest provided . No significant changes from the prior examination . Mild atelectatic change in the left lung base . No pleural effusion , no pneumothorax . Left chest tube position is unchanged ending in the apex of the left hemi thorax .
    OUTPUT:
    
Left chest tube to this is unchanged . No pneumothorax .