Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Lung volumes are low . Heart size is mildly enlarged but unchanged . Mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Patchy opacities in the lung bases is likely reflective of atelectasis in the setting of low lung volumes . No focal consolidation , pleural effusion or pneumothorax is identified . No acute osseous abnormality is seen .
    OUTPUT:
    
Low lung volumes . Patchy bibasilar airspace opacities most likely reflect atelectasis however infection , including atypical pneumonia , can not be completely excluded in the correct clinical setting .