Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: AP portable semi upright view of the chest . Lung volumes are markedly low which limits assessment . There is subtle increase in left basal opacity which could represent pneumonia . Mild bibasilar atelectasis also likely present . No overt edema . No large effusion or pneumothorax . Heart size remains prominent . Mediastinal contour is unchanged . A vascular stent projects over the left axilla . Bony structures are intact .
    OUTPUT:
    
Bibasilar opacities likely represent atelectasis . Increasing left lower lobe opacity , may represent a developing pneumonia .