Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable upright frontal view of the chest . There are low lung volumes . There is the opacity in the left lung base , which may represent atelectasis but can not exclude pneumonia or aspiration in the appropriate clinical setting . No pleural effusion or pneumothorax is seen . The cardiomediastinal silhouette top normal in size .
    OUTPUT:
    
Opacity in the left lung base , which may represent atelectasis but can not exclude pneumonia or aspiration in the appropriate clinical setting . Improved evaluation of the left lower lobe opacity could be achieved with a lateral view .