Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Cardiac , mediastinal and hilar contours are normal . Pulmonary vasculature is not engorged . Lung volumes are lower compared to the previous study with patchy bibasilar airspace opacities noted . Attenuation of the pulmonary vascular markings towards the apices is compatible with underlying emphysema . No pleural effusion or pneumothorax is identified .
    OUTPUT:
    
Low lung volumes with patchy bibasilar airspace opacities , worrisome for pneumonia .