Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Frontal and lateral views of the chest were obtained . There are relatively low lung volumes . Patchy left base retrocardiac opacity may relate to atelectasis , although underlying consolidation can not be excluded . The right lung is clear . The cardiac silhouette is top normal . Mediastinal and hilar contours are unremarkable . Partially imaged is surgical metallic fusion hardware at the lower cervical spine .
    OUTPUT:
    
Low lung volumes . Patchy left base retrocardiac opacity , most likely represents atelectasis , although underlying consolidation can not be excluded .