Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac , mediastinal and hilar contours are normal . Predominantly linear opacities within the left lower lobe likely reflect scarring and bronchiectasis with adjacent pleural thickening . More focal opacity within the periphery of the left lung base may also reflect an area of scarring , though infection can not be completely excluded . No pleural effusion or pneumothorax is seen . There is no pulmonary vascular engorgement . There are no acute osseous abnormalities .
    OUTPUT:
    
Predominantly linear opacities in the left lower lobe likely reflect scarring and known bronchiectasis . More focal opacity in the periphery of the left lung base may also reflect scarring , but infection can not be completely excluded .