Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Low lung volumes accentuating bronchovascular crowding . Thicker linear opacities in both lung bases are probably worsening atelectasis , but could obscure early pneumonia . A small pleural effusion can not be excluded on the left due to costophrenic angle blunting . There is no pneumothorax or pulmonary vascular congestion . The heart is normal in size . Aortic arch calcification is present .
    OUTPUT:
    
Worsened bibasilar atelectasis could obscure pneumonia .