Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: A single portable frontal upright view of the chest was obtained . In comparison to the prior study , there is increased aeration of the left lung ; however dense consolidation persists . Lung volumes remain low . Opacities in the right cardiophrenic angle are largely unchanged and may reflect atelectasis or consolidation . There is no large effusion or pneumothorax .
    OUTPUT:
    
1 . Left lung consolidation , mildly improved . 2 . Persistent low lung volumes . 2 . Bilateral subsegmental atelectasis .