Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The cardiac and mediastinal contours are normal . The right lung is clear without focal opacity , pleural effusion or pneumothorax . In the left lung , there is no focal consolidation ; however , linear opacities in the left lung base may represent atelectasis . The left costophrenic angle is blunted which may represent a pleural scarring . There is no pneumothorax in the left lung . There is no free air beneath the right hemidiaphragm . There is no acute osseous abnormality .
    OUTPUT:
    
Left lower lobe atelectasis . Blunting of the left costophrenic angle may be due to scarring . Please refer to subsequent CT for further details .