Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Subtle linear opacities at the base of the left lung suggest atelectasis however infection should be considered in the appropriate clinical setting . There is no pleural effusion or pneumothorax . The cardiomediastinal and hilar contours are within normal limits .
    OUTPUT:
    
Linear opacities at the base of the left lung suggests atelectasis however infection should be considered in the appropriate clinical setting .