Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Single portable upright chest radiograph . Relative lucency of the bilateral upper lungs suggests background emphysematous changes . Bibasilar opacifications identified , left greater than right . Right - sided opacification may merely represent crowding and atelectasis ; however , more dense opacification on the left may reflect atelectasis , combined with small effusion versus developing pneumonia . Please note , the lung apices are excluded from view by the patient 's overlying chin .
    OUTPUT:
    
Bibasilar opacification , left greater than right . On the left , the opacifications may represent atelectasis with small effusion or developing pneumonia . Background emphysematous changes .