Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Portable semi-upright radiograph of the chest demonstrates increased opacification at the bilateral bases , which may represent atelectasis , aspiration , or pneumonia in the appropriate clinical setting . The heart remains enlarged . Probable small left pleural effusion . No pneumothorax . Endotracheal tube ends 3 .8 cm from the carina .
    OUTPUT:
    
1 . Bibasilar opacities may represent atelectasis , aspiration , or pneumonia in the appropriate clinical setting . 2 . Unremarkable position of the endotracheal tube . However , the endotracheal tube appears narrow in caliber . 3 . Probable small left pleural effusion .