Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: No focal opacity to suggest pneumonia is seen . Unchanged blunting of the costophrenic angles could indicate small pleural effusions or pleural thickening . No pneumothorax or pulmonary edema is present . There is chronic , linear atelectatic scarring in the left mid-thorax . The heart size is within normal limits .
    OUTPUT:
    
No evidence of pneumonia .