Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest radiograph demonstrates a linear opacity projecting over the left lower lung zone likely scarring or atelectasis . Best appreciated on the lateral view , there appears to be increased opacities which may reflect superimposed shadows or alternatively sequela of atelectasis . The right lung is clear . Cardiomediastinal and hilar contours are stable and within normal limits . There is no pleural effusion or pneumothorax .
    OUTPUT:
    
Increased densities present on the lateral chest radiograph at the posterior costophrenic angle relative to study dated ___ may reflect superimposed shadows and atelectasis although infectious process can not be entirely excluded for which clinical correlation is recommended .